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Author name code: caffau
ADS astronomy entries on 2022-09-14
author:"Caffau, Elisabetta"
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Title: Chemical Evolution of R-process Elements in Stars
(CERES). I. Stellar parameters and chemical abundances from Na to Zr
Authors: Lombardo, Linda; Bonifacio, Piercarlo; François, Patrick;
Hansen, Camilla J.; Caffau, Elisabetta; Hanke, Michael; Skúladóttir,
Ása; Arcones, Almudena; Eichler, Marius; Reichert, Moritz; Psaltis,
Athanasios; Koch Hansen, Andreas J.; Sbordone, Luca
2022A&A...665A..10L Altcode: 2022arXiv220613836L
<BR /> Aims: The Chemical Evolution of R-process Elements in Stars
(CERES) project aims to provide a homogeneous analysis of a sample
of metal-poor stars ([Fe/H] < -1.5). We present the stellar
parameters and the chemical abundances of elements up to Zr for a
sample of 52 giant stars. <BR /> Methods: We relied on a sample of
high signal-to-noise UVES spectra. We determined stellar parameters
from Gaia photometry and parallaxes. Chemical abundances were derived
using spectrum synthesis and model atmospheres. <BR /> Results:
We determined chemical abundances of 26 species of 18 elements:
Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y,
and Zr. For several stars, we were able to measure both neutral
and ionised species, including Si, Sc, Mn, and Zr. We have roughly
doubled the number of measurements of Cu for stars at [Fe/H] ≤
−2.5. The homogeneity of the sample made it possible to highlight
the presence of two Zn-rich stars ([Zn/Fe] ∼ +0.7), one r-rich
and the other r-poor. We report the existence of two branches in the
[Zn/Fe] versus [Ni/Fe] plane and suggest that the high [Zn/Fe] branch
is the result of hypernova nucleosynthesis. We discovered two stars
with peculiar light neutron-capture abundance patterns: CES1237+1922
(also known as BS 16085-0050), which is ∼1 dex underabundant in
Sr, Y, and Zr with respect to the other stars in the sample, and
CES2250-4057 (also known as HE 2247-4113), which shows a ∼1 dex
overabundance of Sr with respect to Y and Zr. <BR /> Conclusions: The
high quality of our dataset allowed us to measure hardly detectable
ions. This can provide guidance in the development of line formation
computations that take deviations from local thermodynamic equilibrium
and hydrodynamical effects into account. <P />Chemical abundances
(Table 3) are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr/">cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/665/A10">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/665/A10</A>
<P />Based on observations collected at the European Southern
Observatory under ESO programme 0104.D-0059 and on data obtained from
the ESO Science Archive Facility.
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Title: The Gaia-ESO Public Spectroscopic Survey: Motivation,
implementation, GIRAFFE data processing, analysis, and final data
products
Authors: Gilmore, G.; Randich, S.; Worley, C. C.; Hourihane, A.;
Gonneau, A.; Sacco, G. G.; Lewis, J. R.; Magrini, L.; Francois, P.;
Jeffries, R. D.; Koposov, S. E.; Bragaglia, A.; Alfaro, E. J.; Allende
Prieto, C.; Blomme, R.; Korn, A. J.; Lanzafame, A. C.; Pancino, E.;
Recio-Blanco, A.; Smiljanic, R.; Van Eck, S.; Zwitter, T.; Bensby, T.;
Flaccomio, E.; Irwin, M. J.; Franciosini, E.; Morbidelli, L.; Damiani,
F.; Bonito, R.; Friel, E. D.; Vink, J. S.; Prisinzano, L.; Abbas,
U.; Hatzidimitriou, D.; Held, E. V.; Jordi, C.; Paunzen, E.; Spagna,
A.; Jackson, R. J.; Maiz Apellaniz, J.; Asplund, M.; Bonifacio, P.;
Feltzing, S.; Binney, J.; Drew, J.; Ferguson, A. M. N.; Micela, G.;
Negueruela, I.; Prusti, T.; Rix, H. -W.; Vallenari, A.; Bergemann,
M.; Casey, A. R.; de Laverny, P.; Frasca, A.; Hill, V.; Lind, K.;
Sbordone, L.; Sousa, S. G.; Adibekyan, V.; Caffau, E.; Daflon, S.;
Feuillet, D. K.; Gebran, M.; Gonzalez Hernandez, J. I.; Guiglion,
G.; Herrero, A.; Lobel, A.; Merle, T.; Mikolaitis, S.; Montes, D.;
Morel, T.; Ruchti, G.; Soubiran, C.; Tabernero, H. M.; Tautvaisiene,
G.; Traven, G.; Valentini, M.; Van der Swaelmen, M.; Villanova, S.;
Viscasillas Vazquez, C.; Bayo, A.; Biazzo, K.; Carraro, G.; Edvardsson,
B.; Heiter, U.; Jofre, P.; Marconi, G.; Martayan, C.; Masseron, T.;
Monaco, L.; Walton, N. A.; Zaggia, S.; Aguirre Borsen-Koch, V.; Alves,
J.; Balaguer-Nunez, L.; Barklem, P. S.; Barrado, D.; Bellazzini, M.;
Berlanas, S. R.; Binks, A. S.; Bressan, A.; Capuzzo-Dolcetta, R.;
Casagrande, L.; Casamiquela, L.; Collins, R. S.; D'Orazi, V.; Dantas,
M. L. L.; Debattista, V. P.; Delgado-Mena, E.; Di Marcantonio, P.;
Drazdauskas, A.; Evans, N. W.; Famaey, B.; Franchini, M.; Fremat, Y.;
Fu, X.; Geisler, D.; Gerhard, O.; Gonzalez Solares, E. A.; Grebel,
E. K.; Gutierrez Albarran, M. L.; Jimenez-Esteban, F.; Jonsson, H.;
Khachaturyants, T.; Kordopatis, G.; Kos, J.; Lagarde, N.; Ludwig,
H. -G.; Mahy, L.; Mapelli, M.; Marfil, E.; Martell, S. L.; Messina,
S.; Miglio, A.; Minchev, I.; Moitinho, A.; Montalban, J.; Monteiro,
M. J. P. F. G.; Morossi, C.; Mowlavi, N.; Mucciarelli, A.; Murphy,
D. N. A.; Nardetto, N.; Ortolani, S.; Paletou, F.; Palous, J.;
Pickering, J. C.; Quirrenbach, A.; Re Fiorentin, P.; Read, J. I.;
Romano, D.; Ryde, N.; Sanna, N.; Santos, W.; Seabroke, G. M.; Spina,
L.; Steinmetz, M.; Stonkute, E.; Sutorius, E.; Thevenin, F.; Tosi,
M.; Tsantaki, M.; Wright, N.; Wyse, R. F. G.; Zoccali, M.; Zorec,
J.; Zucker, D. B.
2022arXiv220805432G Altcode:
The Gaia-ESO Public Spectroscopic Survey is an ambitious project
designed to obtain astrophysical parameters and elemental abundances
for 100,000 stars, including large representative samples of the
stellar populations in the Galaxy, and a well-defined sample of 60
(plus 20 archive) open clusters. We provide internally consistent
results calibrated on benchmark stars and star clusters, extending
across a very wide range of abundances and ages. This provides a
legacy data set of intrinsic value, and equally a large wide-ranging
dataset that is of value for homogenisation of other and future
stellar surveys and Gaia's astrophysical parameters. This article
provides an overview of the survey methodology, the scientific aims,
and the implementation, including a description of the data processing
for the GIRAFFE spectra. A companion paper (arXiv:2206.02901)
introduces the survey results. Gaia-ESO aspires to quantify both
random and systematic contributions to measurement uncertainties. Thus
all available spectroscopic analysis techniques are utilised, each
spectrum being analysed by up to several different analysis pipelines,
with considerable effort being made to homogenise and calibrate the
resulting parameters. We describe here the sequence of activities up to
delivery of processed data products to the ESO Science Archive Facility
for open use. The Gaia-ESO Survey obtained 202,000 spectra of 115,000
stars using 340 allocated VLT nights between December 2011 and January
2018 from GIRAFFE and UVES. The full consistently reduced final data set
of spectra was released through the ESO Science Archive Facility in late
2020, with the full astrophysical parameters sets following in 2022.
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Title: The Pristine survey - XVIII. C-19: tidal debris of a dark
matter-dominated globular cluster?
Authors: Errani, Raphaël; Navarro, Julio F.; Ibata, Rodrigo;
Martin, Nicolas; Yuan, Zhen; Aguado, David S.; Bonifacio, Piercarlo;
Caffau, Elisabetta; González Hernández, Jonay I.; Malhan, Khyati;
Sánchez-Janssen, Rubén; Sestito, Federico; Starkenburg, Else;
Thomas, Guillaume F.; Venn, Kim A.
2022MNRAS.514.3532E Altcode: 2022arXiv220302513E; 2022MNRAS.tmp.1475E
The recently discovered C-19 stellar stream is a collection of
kinematically associated metal-poor stars in the halo of the Milky Way
lacking an obvious progenitor. The stream spans across an arc of ~15°
in the sky, and orbit-fitting suggests an apocentric distance of ${\sim}
20\, \mathrm{kpc}$ and a pericentre of ${\sim} 10\, \mathrm{kpc}$. The
narrow metallicity dispersion of stars with available spectra, together
with light element abundance variations, suggests a globular cluster
(GC) origin. The observed metallicity ([Fe/H] ≍ -3.4), however,
is much lower than that of any known GC. In addition, the width
and velocity dispersion of the stream are similar to those expected
from disrupting dwarf galaxies, and substantially larger than the
tidal debris of GCs able to disrupt on C-19's orbit. We propose
here an unconventional model where the C-19 progenitor is a dark
matter-dominated stellar system with GC-like abundance patterns. We
use N-body simulations to show that the tidal disruption of a ~100
pc King-model stellar component embedded in a ~20 km s<SUP>-1</SUP>
cuspy cold dark matter halo yields debris consistent with C-19's
observed width and velocity dispersion. The stellar component of the
progenitor is fully disrupted, and is spread over two distinct streams,
one corresponding to C-19 and another possibly hiding behind the
Galactic plane. If such companion stream were found, it would suggest
that dark matter-dominated dwarfs may also develop GC-like enrichment
patterns, a finding that would inform our theoretical understanding of
the formation of multiple populations in GCs and dwarf galaxies alike.
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Title: The Pristine survey - XVII. The C-19 stream is dynamically
hot and more extended than previously thought
Authors: Yuan, Zhen; Martin, Nicolas F.; Ibata, Rodrigo A.; Caffau,
Elisabetta; Bonifacio, Piercarlo; Mashonkina, Lyudmila I.; Errani,
Raphaël; Doliva-Dolinsky, Amandine; Starkenburg, Else; Venn, Kim A.;
Arentsen, Anke; Aguado, David S.; Bellazzini, Michele; Famaey, Benoit;
Fouesneau, Morgan; González Hernández, Jonay I.; Jablonka, Pascale;
Lardo, Carmela; Malhan, Khyati; Navarro, Julio F.; Sánchez Janssen,
Rubén; Sestito, Federico; Thomas, Guillaume F.; Viswanathan, Akshara;
Vitali, Sara
2022MNRAS.514.1664Y Altcode: 2022arXiv220302512Y; 2022MNRAS.tmp.1369Y
The C-19 stream is the most metal-poor stellar system ever discovered,
with a mean metallicity [Fe/H] = -3.38 ± 0.06. Its low metallicity
dispersion (σ<SUB>[Fe/H]</SUB> < 0.18 at the 95 per cent
confidence level) and variations in sodium abundances strongly suggest
a globular cluster origin. In this work, we use Very Large Telescope
(VLT)/UV-Visual Echelle Spectrograph (UVES) spectra of seven C-19
stars to derive more precise velocity measurements for member stars,
and to identify two new members with radial velocities and metallicities
consistent with the stream's properties. One of these new member stars
is located 30° away from the previously identified body of C-19,
implying that the stream is significantly more extended than previously
known and that more members likely await discovery. In the main part
of C-19, we measure a radial velocity dispersion σ<SUB>v</SUB> =
6.2$^{+2.0}_{-1.4}{\rm \, km\, s^{-1}}$ from nine members, and a stream
width of 0.56° ± 0.08°, equivalent to ~158 pc at a heliocentric
distance of 18 kpc. These confirm that C-19 is comparatively hotter,
dynamically, than other known globular cluster streams and shares
the properties of faint dwarf galaxy streams. On the other hand, the
variations in the Na abundances of the three newly observed bright
member stars, the variations in Mg and Al for two of them, and the
normal Ba abundance of the one star where it can be measured provide
further evidence for a globular cluster origin. The tension between the
dynamical and chemical properties of C-19 suggests that its progenitor
experienced a complex birth environment or disruption history.
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Title: VizieR Online Data Catalog: CERES I. Abundances for 52 star
(Lombardo+, 2022)
Authors: Lombardo, L.; Bonifacio, P.; Francois, P.; Hansen, C. J.;
Caffau, E.; Hanke, M.; Skuladottir, A.; Arcones, A.; Eichler, M.;
Reichert, M.; Psaltis, A.; Koch Hansen, A. J.; Sbordone, L.
2022yCat..36650010L Altcode:
The target stars were observed with the Ultraviolet and Visual Echelle
Spectrograph (UVES) of the Very Large Telescope (VLT) at the European
Southern Observatory (ESO) during two runs (November 2019 and March
2020) with differing exposures to reach a S/N of 50 to 120 per pixel
at 390nm for most stars. <P />Our own observations were complemented
with archival data of comparable quality. All the archival data used
were acquired prior to 2019. <P />We present a homogeneous set of
stellar parameters and a chemical abundance analysis of elements
from Na to Zr for a sample of 52 Galactic halo giant stars with
-3:58<=[Fe/H]<=-1.79. <P />(2 data files).
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Title: Gaia Data Release 3: Summary of the content and survey
properties
Authors: Gaia Collaboration; Vallenari, A.; Brown, A. G. A.; Prusti,
T.; de Bruijne, J. H. J.; Arenou, F.; Babusiaux, C.; Biermann, M.;
Creevey, O. L.; Ducourant, C.; Evans, D. W.; Eyer, L.; Guerra, R.;
Hutton, A.; Jordi, C.; Klioner, S. A.; Lammers, U. L.; Lindegren,
L.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.;
Sartoretti, P.; Soubiran, C.; Tanga, P.; Walton, N. A.; Bailer-Jones,
C. A. L.; Bastian, U.; Drimmel, R.; Jansen, F.; Katz, D.; Lattanzi,
M. G.; van Leeuwen, F.; Bakker, J.; Cacciari, C.; Castañeda, J.;
De Angeli, F.; Fabricius, C.; Fouesneau, M.; Frémat, Y.; Galluccio,
L.; Guerrier, A.; Heiter, U.; Masana, E.; Messineo, R.; Mowlavi, N.;
Nicolas, C.; Nienartowicz, K.; Pailler, F.; Panuzzo, P.; Riclet,
F.; Roux, W.; Seabroke, G. M.; Sordoørcit, R.; Thévenin, F.;
Gracia-Abril, G.; Portell, J.; Teyssier, D.; Altmann, M.; Andrae, R.;
Audard, M.; Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme,
R.; Burgess, P. W.; Busonero, D.; Busso, G.; Cánovas, H.; Carry,
B.; Cellino, A.; Cheek, N.; Clementini, G.; Damerdji, Y.; Davidson,
M.; de Teodoro, P.; Nuñez Campos, M.; Delchambre, L.; Dell'Oro,
A.; Esquej, P.; Fernández-Hernández, J.; Fraile, E.; Garabato, D.;
García-Lario, P.; Gosset, E.; Haigron, R.; Halbwachs, J. -L.; Hambly,
N. C.; Harrison, D. L.; Hernández, J.; Hestroffer, D.; Hodgkin,
S. T.; Holl, B.; Janßen, K.; Jevardat de Fombelle, G.; Jordan,
S.; Krone-Martins, A.; Lanzafame, A. C.; Löffler, W.; Marchal, O.;
Marrese, P. M.; Moitinho, A.; Muinonen, K.; Osborne, P.; Pancino,
E.; Pauwels, T.; Recio-Blanco, A.; Reylé, C.; Riello, M.; Rimoldini,
L.; Roegiers, T.; Rybizki, J.; Sarro, L. M.; Siopis, C.; Smith, M.;
Sozzetti, A.; Utrilla, E.; van Leeuwen, M.; Abbas, U.; Ábrahám, P.;
Abreu Aramburu, A.; Aerts, C.; Aguado, J. J.; Ajaj, M.; Aldea-Montero,
F.; Altavilla, G.; Álvarez, M. A.; Alves, J.; Anders, F.; Anderson,
R. I.; Anglada Varela, E.; Antoja, T.; Baines, D.; Baker, S. G.;
Balaguer-Núñez, L.; Balbinot, E.; Balog, Z.; Barache, C.; Barbato,
D.; Barros, M.; Barstow, M. A.; Bartolomé, S.; Bassilana, J. -L.;
Bauchet, N.; Becciani, U.; Bellazzini, M.; Berihuete, A.; Bernet, M.;
Bertone, S.; Bianchi, L.; Binnenfeld, A.; Blanco-Cuaresma, S.; Blazere,
A.; Boch, T.; Bombrun, A.; Bossini, D.; Bouquillon, S.; Bragaglia, A.;
Bramante, L.; Breedt, E.; Bressan, A.; Brouillet, N.; Brugaletta, E.;
Bucciarelli, B.; Burlacu, A.; Butkevich, A. G.; Buzzi, R.; Caffau,
E.; Cancelliere, R.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.;
Carnerero, M. I.; Carrasco, J. M.; Casamiquela, L.; Castellani, M.;
Castro-Ginard, A.; Chaoul, L.; Charlot, P.; Chemin, L.; Chiaramida,
V.; Chiavassa, A.; Chornay, N.; Comoretto, G.; Contursi, G.; Cooper,
W. J.; Cornez, T.; Cowell, S.; Crifo, F.; Cropper, M.; Crosta, M.;
Crowley, C.; Dafonte, C.; Dapergolas, A.; David, M.; David, P.; de
Laverny, P.; De Luise, F.; De March, R.; De Ridder, J.; de Souza, R.;
de Torres, A.; del Peloso, E. F.; del Pozo, E.; Delbo, M.; Delgado,
A.; Delisle, J. -B.; Demouchy, C.; Dharmawardena, T. E.; Di Matteo,
P.; Diakite, S.; Diener, C.; Distefano, E.; Dolding, C.; Edvardsson,
B.; Enke, H.; Fabre, C.; Fabrizio, M.; Faigler, S.; Fedorets, G.;
Fernique, P.; Fienga, A.; Figueras, F.; Fournier, Y.; Fouron, C.;
Fragkoudi, F.; Gai, M.; Garcia-Gutierrez, A.; Garcia-Reinaldos, M.;
García-Torres, M.; Garofalo, A.; Gavel, A.; Gavras, P.; Gerlach,
E.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona, S.; Giuffrida, G.;
Gomel, R.; Gomez, A.; González-Núñez, J.; González-Santamaría,
I.; González-Vidal, J. J.; Granvik, M.; Guillout, P.; Guiraud, J.;
Gutiérrez-Sánchez, R.; Guy, L. P.; Hatzidimitriou, D.; Hauser, M.;
Haywood, M.; Helmer, A.; Helmi, A.; Sarmiento, M. H.; Hidalgo, S. L.;
Hilger, T.; Hładczuk, N.; Hobbs, D.; Holland, G.; Huckle, H. E.;
Jardine, K.; Jasniewicz, G.; Jean-Antoine Piccolo, A.; Jiménez-Arranz,
Ó.; Jorissen, A.; Juaristi Campillo, J.; Julbe, F.; Karbevska, L.;
Kervella, P.; Khanna, S.; Kontizas, M.; Kordopatis, G.; Korn, A. J.;
Kóspál, Á; Kostrzewa-Rutkowska, Z.; Kruszyńska, K.; Kun, M.;
Laizeau, P.; Lambert, S.; Lanza, A. F.; Lasne, Y.; Le Campion, J. -F.;
Lebreton, Y.; Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi,
I.; Liao, S.; Licata, E. L.; Lindstrøm, H. E. P.; Lister, T. A.;
Livanou, E.; Lobel, A.; Lorca, A.; Loup, C.; Madrero Pardo, P.;
Magdaleno Romeo, A.; Managau, S.; Mann, R. G.; Manteiga, M.; Marchant,
J. M.; Marconi, M.; Marcos, J.; Marcos Santos, M. M. S.; Marín Pina,
D.; Marinoni, S.; Marocco, F.; Marshall, D. J.; Polo, L. Martin;
Martín-Fleitas, J. M.; Marton, G.; Mary, N.; Masip, A.; Massari,
D.; Mastrobuono-Battisti, A.; Mazeh, T.; McMillan, P. J.; Messina,
S.; Michalik, D.; Millar, N. R.; Mints, A.; Molina, D.; Molinaro, R.;
Molnár, L.; Monari, G.; Monguió, M.; Montegriffo, P.; Montero, A.;
Mor, R.; Mora, A.; Morbidelli, R.; Morel, T.; Morris, D.; Muraveva, T.;
Murphy, C. P.; Musella, I.; Nagy, Z.; Noval, L.; Ocaña, F.; Ogden, A.;
Ordenovic, C.; Osinde, J. O.; Pagani, C.; Pagano, I.; Palaversa, L.;
Palicio, P. A.; Pallas-Quintela, L.; Panahi, A.; Payne-Wardenaar, S.;
Peñalosa Esteller, X.; Penttilä, A.; Pichon, B.; Piersimoni, A. M.;
Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Prša, A.; Pulone,
L.; Racero, E.; Ragaini, S.; Rainer, M.; Raiteri, C. M.; Rambaux, N.;
Ramos, P.; Ramos-Lerate, M.; Re Fiorentin, P.; Regibo, S.; Richards,
P. J.; Rios Diaz, C.; Ripepi, V.; Riva, A.; Rix, H. -W.; Rixon, G.;
Robichon, N.; Robin, A. C.; Robin, C.; Roelens, M.; Rogues, H. R. O.;
Rohrbasser, L.; Romero-Gómez, M.; Rowell, N.; Royer, F.; Ruz Mieres,
D.; Rybicki, K. A.; Sadowski, G.; Sáez Núñez, A.; Sagristà Sellés,
A.; Sahlmann, J.; Salguero, E.; Samaras, N.; Sanchez Gimenez, V.;
Sanna, N.; Santoveña, R.; Sarasso, M.; Schultheis, M.; Sciacca, E.;
Segol, M.; Segovia, J. C.; Ségransan, D.; Semeux, D.; Shahaf, S.;
Siddiqui, H. I.; Siebert, A.; Siltala, L.; Silvelo, A.; Slezak, E.;
Slezak, I.; Smart, R. L.; Snaith, O. N.; Solano, E.; Solitro, F.;
Souami, D.; Souchay, J.; Spagna, A.; Spina, L.; Spoto, F.; Steele,
I. A.; Steidelmüller, H.; Stephenson, C. A.; Süveges, M.; Surdej,
J.; Szabados, L.; Szegedi-Elek, E.; Taris, F.; Taylo, M. B.; Teixeira,
R.; Tolomei, L.; Tonello, N.; Torra, F.; Torra, J.; Torralba Elipe,
G.; Trabucchi, M.; Tsounis, A. T.; Turon, C.; Ulla, A.; Unger, N.;
Vaillant, M. V.; van Dillen, E.; van Reeven, W.; Vanel, O.; Vecchiato,
A.; Viala, Y.; Vicente, D.; Voutsinas, S.; Weiler, M.; Wevers, T.;
Wyrzykowski, L.; Yoldas, A.; Yvard, P.; Zhao, H.; Zorec, J.; Zucker,
S.; Zwitter, T.
2022arXiv220800211G Altcode:
We present the third data release of the European Space Agency's Gaia
mission, GDR3. The GDR3 catalogue is the outcome of the processing
of raw data collected with the Gaia instruments during the first
34 months of the mission by the Gaia Data Processing and Analysis
Consortium. The GDR3 catalogue contains the same source list, celestial
positions, proper motions, parallaxes, and broad band photometry in
the G, G$_{BP}$, and G$_{RP}$ pass-bands already present in the Early
Third Data Release. GDR3 introduces an impressive wealth of new data
products. More than 33 million objects in the ranges $G_{rvs} < 14$
and $3100 <T_{eff} <14500 $, have new determinations of their
mean radial velocities based on data collected by Gaia. We provide
G$_{rvs}$ magnitudes for most sources with radial velocities, and a
line broadening parameter is listed for a subset of these. Mean Gaia
spectra are made available to the community. The GDR3 catalogue includes
about 1 million mean spectra from the radial velocity spectrometer,
and about 220 million low-resolution blue and red prism photometer
BPRP mean spectra. The results of the analysis of epoch photometry are
provided for some 10 million sources across 24 variability types. GDR3
includes astrophysical parameters and source class probabilities for
about 470 million and 1500 million sources, respectively, including
stars, galaxies, and quasars. Orbital elements and trend parameters are
provided for some $800\,000$ astrometric, spectroscopic and eclipsing
binaries. More than $150\,000$ Solar System objects, including new
discoveries, with preliminary orbital solutions and individual epoch
observations are part of this release. Reflectance spectra derived
from the epoch BPRP spectral data are published for about 60\,000
asteroids. Finally, an additional data set is provided, namely the
Gaia Andromeda Photometric Survey (abridged)
---------------------------------------------------------
Title: Gaia Data Release 3: Properties of the line broadening
parameter derived with the Radial Velocity Spectrometer (RVS)
Authors: Frémat, Y.; Royer, F.; Marchal, O.; Blomme, R.; Sartoretti,
P.; Guerrier, A.; Panuzzo, P.; Katz, D.; Seabroke, G. M.; Thévenin,
F.; Cropper, M.; Benson, K.; Damerdji, Y.; Haigron, R.; Lobel, A.;
Smith, M.; Baker, S. G.; Chemin, L.; David, M.; Dolding, C.; Gosset,
E.; Janßen, K.; Jasniewicz, G.; Plum, G.; Samaras, N.; Snaith,
O.; Soubiran, C.; Vanel, O.; Zorec, J.; Zwitter, T.; Brouillet, N.;
Caffau, E.; Crifo, F.; Fabre, C.; Fragkoudi, F.; Huckle, H. E.; Lasne,
Y.; Leclerc, N.; Mastrobuono-Battisti, A.; Jean-Antoine Piccolo, A.;
Viala, Y.
2022arXiv220610986F Altcode:
The third release of the Gaia catalogue contains the radial velocities
for 33,812,183 stars having effective temperatures ranging from
3100 K to 14,500 K. The measurements are based on the comparison
of the observed RVS spectrum (wavelength coverage: 846--870 nm,
median resolving power: 11,500) to synthetic data broadened
to the adequate Along-Scan Line Spread Function. The additional
line-broadening, fitted as it would only be due to axial rotation,
is also produced by the pipeline and is available in the catalogue
(field name gaia_source:vbroad). To describe the properties of the
line-broadening information extracted from the RVS and published in
the catalogue, as well as to analyse the limitations imposed by the
adopted method, wavelength range, and instrument. We use simulations
to express the link existing between the line broadening measurement
provided in Gaia Data Release 3 and Vsin(i). We then compare the
observed values to the measurements published by various catalogues
and surveys (GALAH, APOGEE, LAMOST, ...). While we recommend being
cautious in the interpretation of the vbroad measurement, we also
find a reasonable global agreement between the Gaia Data Release 3
line broadening values and those found in the other catalogues. We
discuss and establish the validity domain of the published vbroad
values. The estimate tends to be overestimated at the lower vsini
end, and at $T_\mathrm{eff}>7500\,\mathrm{K}$ its quality and
significance degrade rapidly when $G_\mathrm{RVS}>10$. Despite
all the known and reported limitations, the Gaia Data Release 3
line broadening catalogue contains the measurements obtained for
3,524,677 stars with $T_\mathrm{eff}$\ ranging from 3500 to 14,500 K,
and $G_\mathrm{RVS}<12$. It gathers the largest stellar sample ever
considered for the purpose, and allows a first mapping of the \Gaia\
line broadening parameter across the HR diagram.
---------------------------------------------------------
Title: The Gaia-ESO Public Spectroscopic Survey: Implementation,
data products, open cluster survey, science, and legacy
Authors: Randich, S.; Gilmore, G.; Magrini, L.; Sacco, G. G.; Jackson,
R. J.; Jeffries, R. D.; Worley, C. C.; Hourihane, A.; Gonneau, A.;
Viscasillas Vàzquez, C.; Franciosini, E.; Lewis, J. R.; Alfaro, E. J.;
Allende Prieto, C.; Blomme, T. Bensby R.; Bragaglia, A.; Flaccomio, E.;
François, P.; Irwin, M. J.; Koposov, S. E.; Korn, A. J.; Lanzafame,
A. C.; Pancino, E.; Recio-Blanco, A.; Smiljanic, R.; Van Eck, S.;
Zwitter, T.; Asplund, M.; Bonifacio, P.; Feltzing, S.; Binney, J.;
Drew, J.; Ferguson, A. M. N.; Micela, G.; Negueruela, I.; Prusti,
T.; Rix, H. -W.; Vallenari, A.; Bayo, A.; Bergemann, M.; Biazzo, K.;
Carraro, G.; Casey, A. R.; Damiani, F.; Frasca, A.; Heiter, U.; Hill,
V.; Jofré, P.; de Laverny, P.; Lind, K.; Marconi, G.; Martayan, C.;
Masseron, T.; Monaco, L.; Morbidelli, L.; Prisinzano, L.; Sbordone,
L.; Sousa, S. G.; Zaggia, S.; Adibekyan, V.; Bonito, R.; Caffau,
E.; Daflon, S.; Feuillet, D. K.; Gebran, M.; González Hernández,
J. I.; Guiglion, G.; Herrero, A.; Lobel, A.; Maíz Apellániz,
J.; Merle, T.; Mikolaitis, S.; Montes, D.; Morel, T.; Soubiran,
C.; Spina, L.; Tabernero, H. M.; Tautvaišienė, G.; Traven, G.;
Valentini, M.; Van der Swaelmen, M.; Villanova, S.; Wright, N. J.;
Abbas, U.; Aguirre Børsen-Koch, V.; Alves, J.; Balaguer-Núnez,
L.; Barklem, P. S.; Barrado, D.; Berlanas, S. R.; Binks, A. S.;
Bressan, A.; Capuzzo--Dolcetta, R.; Casagrande, L.; Casamiquela, L.;
Collins, R. S.; D'Orazi, V.; Dantas, M. L. L.; Debattista, V. P.;
Delgado-Mena, E.; Di Marcantonio, P.; Drazdauskas, A.; Evans, N. W.;
Famaey, B.; Franchini, M.; Frémat, Y.; Friel, E. D.; Fu, X.; Geisler,
D.; Gerhard, O.; González Solares, E. A.; Grebel, E. K.; Gutiérrez
Albarrán, M. L.; Hatzidimitriou, D.; Held, E. V.; Jiménez-Esteban,
F.; Jönsson, H.; Jordi, C.; Khachaturyants, T.; Kordopatis, G.; Kos,
J.; Lagarde, N.; Mahy, L.; Mapelli, M.; Marfil, E.; Martell, S. L.;
Messina, S.; Miglio, A.; Minchev, I.; Moitinho, A.; Montalban, J.;
Monteiro, M. J. P. F. G.; Morossi, C.; Mowlavi, N.; Mucciarelli, A.;
Murphy, D. N. A.; Nardetto, N.; Ortolani, S.; Paletou, F.; Palouus, J.;
Paunzen, E.; Pickering, J. C.; Quirrenbach, A.; Re Fiorentin, P.; Read,
J. I.; Romano, D.; Ryde, N.; Sanna, N.; Santos, W.; Seabroke, G. M.;
Spagna, A.; Steinmetz, M.; Stonkuté, E.; Sutorius, E.; Thévenin,
F.; Tosi, M.; Tsantaki, M.; Vink, J. S.; Wright, N.; Wyse, R. F. G.;
Zoccali, M.; Zorec, J.; Zucker, D. B.; Walton, N. A.
2022arXiv220602901R Altcode:
In the last 15 years different ground-based spectroscopic surveys
have been started (and completed) with the general aim of delivering
stellar parameters and elemental abundances for large samples of
Galactic stars, complementing Gaia astrometry. Among those surveys,
the Gaia-ESO Public Spectroscopic Survey (GES), the only one performed
on a 8m class telescope, was designed to target 100,000 stars using
FLAMES on the ESO VLT (both Giraffe and UVES spectrographs), covering
all the Milky Way populations, with a special focus on open star
clusters. This article provides an overview of the survey implementation
(observations, data quality, analysis and its success, data products,
and releases), of the open cluster survey, of the science results and
potential, and of the survey legacy. A companion article (Gilmore et
al.) reviews the overall survey motivation, strategy, Giraffe pipeline
data reduction, organisation, and workflow. The GES has determined
homogeneous good-quality radial velocities and stellar parameters for a
large fraction of its more than 110,000 unique target stars. Elemental
abundances were derived for up to 31 elements for targets observed with
UVES. Lithium abundances are delivered for about 1/3 of the sample. The
analysis and homogenisation strategies have proven to be successful;
several science topics have been addressed by the Gaia-ESO consortium
and the community, with many highlight results achieved. The final
catalogue has been released through the ESO archive at the end of
May 2022, including the complete set of advanced data products. In
addition to these results, the Gaia-ESO Survey will leave a very
important legacy, for several aspects and for many years to come.
---------------------------------------------------------
Title: Gaia Data Release 3: G_RVS photometry from the RVS spectra
Authors: Sartoretti, P.; Marchal, O.; Babusiaux, C.; Jordi, C.;
Guerrier, A.; Panuzzo, P.; Katz, D.; Seabroke, G. M.; Thévenin, F.;
Cropper, M.; Benson, K.; Blomme, R.; Haigron, R.; Smith, M.; Baker,
S.; Chemin, L.; David, M.; Dolding, C.; Frémat, Y.; Janssen, K.;
Jasniewicz, G.; Lobel, A.; Plum, G.; Samaras, N.; Snaith, O.; Soubiran,
C.; Vanel, O.; Zwitter, T.; Brouillet, N.; Caffau, E.; Crifo, F.;
Fabre, C.; Frakgoudi, F.; Jean-Antoine Piccolo, A.; Huckle, H. E.;
Lasne, Y.; Leclerc, N.; Mastrobuono-Battisti, A.; Royer, F.; Viala,
Y.; Zorec, J.
2022arXiv220605725S Altcode:
Gaia Data Release 3 (DR3) contains the first release of magnitudes
estimated from the integration of Radial Velocity Spectrometer
(RVS) spectra for a sample of about 32.2 million stars brighter than
G_RVS~14 mag (or G~15 mag). In this paper, we describe the data used
and the approach adopted to derive and validate the G_RVS magnitudes
published in DR3. We also provide estimates of the G_RVS passband
and associated G_RVS zero-point. We derived G_RVS photometry from
the integration of RVS spectra over the wavelength range from 846
to 870 nm. We processed these spectra following a procedure similar
to that used for DR2, but incorporating several improvements that
allow a better estimation of G_RVS. These improvements pertain to the
stray-light background estimation, the line spread function calibration,
and the detection of spectra contaminated by nearby relatively bright
sources. We calibrated the G_RVS zero-point every 30 hours based on the
reference magnitudes of constant stars from the Hipparcos catalogue,
and used them to transform the integrated flux of the cleaned and
calibrated spectra into epoch magnitudes. The G_RVS magnitude of a
star published in DR3 is the median of the epoch magnitudes for that
star. We estimated the G_RVS passband by comparing the RVS spectra
of 108 bright stars with their flux-calibrated spectra from external
spectrophotometric libraries. The G_RVS magnitude provides information
that is complementary to that obtained from the G, G_BP, and G_RP
magnitudes, which is useful for constraining stellar metallicity and
interstellar extinction. The median precision of G_RVS measurements
ranges from about 0.006 mag for the brighter stars (i.e. with 3.5
< G_RVS < 6.5 mag) to 0.125 mag at the faint end. The derived
G_RVS passband shows that the effective transmittance of the RVS is
approximately 1.23 times better than the pre-launch estimate.
---------------------------------------------------------
Title: Gaia Data Release 3: Mapping the asymmetric disc of the
Milky Way
Authors: Gaia Collaboration; Drimmel, R.; Romero-Gomez, M.; Chemin,
L.; Ramos, P.; Poggio, E.; Ripepi, V.; Andrae, R.; Blomme, R.;
Cantat-Gaudin, T.; Castro-Ginard, A.; Clementini, G.; Figueras,
F.; Fouesneau, M.; Fremat, Y.; Jardine, K.; Khanna, S.; Lobel, A.;
Marshall, D. J.; Muraveva, T.; Brown, A. G. A.; Vallenari, A.; Prusti,
T.; de Bruijne, J. H. J.; Arenou, F.; Babusiaux, C.; Biermann, M.;
Creevey, O. L.; Ducourant, C.; Evans, D. W.; Eyer, L.; Guerra, R.;
Hutton, A.; Jordi, C.; Klioner, S. A.; Lammers, U. L.; Lindegren,
L.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.;
Sartoretti, P.; Soubiran, C.; Tanga, P.; Walton, N. A.; Bailer-Jones,
C. A. L.; Bastian, U.; Jansen, F.; Katz, D.; Lattanzi, M. G.; van
Leeuwen, F.; Bakker, J.; Cacciari, C.; Castañeda, J.; De Angeli, F.;
Fabricius, C.; Galluccio, L.; Guerrier, A.; Heiter, U.; Masana, E.;
Messineo, R.; Mowlavi, N.; Nicolas, C.; Nienartowicz, K.; Pailler, F.;
Panuzzo, P.; Riclet, F.; Roux, W.; Seabroke, G. M.; Sordoørcit, R.;
Thévenin, F.; Gracia-Abril, G.; Portell, J.; Teyssier, D.; Altmann,
M.; Audard, M.; Bellas-Velidis, I.; Benson, K.; Berthier, J.; Burgess,
P. W.; Busonero, D.; Busso, G.; Cánovas, H.; Carry, B.; Cellino, A.;
Cheek, N.; Damerdji, Y.; Davidson, M.; de Teodoro, P.; Nuñez Campos,
M.; Delchambre, L.; Dell'Oro, A.; Esquej, P.; Fernández-Hernández,
J.; Fraile, E.; Garabato, D.; García-Lario, P.; Gosset, E.; Haigron,
R.; Halbwachs, J. -L.; Hambly, N. C.; Harrison, D. L.; Hernández,
J.; Hestroffer, D.; Hodgkin, S. T.; Holl, B.; Janßen, K.; Jevardat
de Fombelle, G.; Jordan, S.; Krone-Martins, A.; Lanzafame, A. C.;
Löffler, W.; Marchal, O.; Marrese, P. M.; Moitinho, A.; Muinonen, K.;
Osborne, P.; Pancino, E.; Pauwels, T.; Recio-Blanco, A.; Reylé, C.;
Riello, M.; Rimoldini, L.; Roegiers, T.; Rybizki, J.; Sarro, L. M.;
Siopis, C.; Smith, M.; Sozzetti, A.; Utrilla, E.; van Leeuwen, M.;
Abbas, U.; Ábrahám, P.; Abreu Aramburu, A.; Aerts, C.; Aguado,
J. J.; Ajaj, M.; Aldea-Montero, F.; Altavilla, G.; Álvarez, M. A.;
Alves, J.; Anders, F.; Anderson, R. I.; Anglada Varela, E.; Antoja, T.;
Baines, D.; Baker, S. G.; Balaguer-Núñez, L.; Balbinot, E.; Balog,
Z.; Barache, C.; Barbato, D.; Barros, M.; Barstow, M. A.; Bartolomé,
S.; Bassilana, J. -L.; Bauchet, N.; Becciani, U.; Bellazzini, M.;
Berihuete, A.; Bernet, M.; Bertone, S.; Bianchi, L.; Binnenfeld, A.;
Blanco-Cuaresma, S.; Blazere, A.; Boch, T.; Bombrun, A.; Bossini, D.;
Bouquillon, S.; Bragaglia, A.; Bramante, L.; Breedt, E.; Bressan, A.;
Brouillet, N.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.; Butkevich,
A. G.; Buzzi, R.; Caffau, E.; Cancelliere, R.; Carballo, R.; Carlucci,
T.; Carnerero, M. I.; Carrasco, J. M.; Casamiquela, L.; Castellani,
M.; Chaoul, L.; Charlot, P.; Chiaramida, V.; Chiavassa, A.; Chornay,
N.; Comoretto, G.; Contursi, G.; Cooper, W. J.; Cornez, T.; Cowell,
S.; Crifo, F.; Cropper, M.; Crosta, M.; Crowley, C.; Dafonte, C.;
Dapergolas, A.; David, M.; David, P.; de Laverny, P.; De Luise, F.;
De March, R.; De Ridder, J.; de Souza, R.; de Torres, A.; del Peloso,
E. F.; del Pozo, E.; Delbo, M.; Delgado, A.; Delisle, J. -B.; Demouchy,
C.; Dharmawardena, T. E.; Di Matteo, P.; Diakite, S.; Diener, C.;
Distefano, E.; Dolding, C.; Edvardsson, B.; Enke, H.; Fabre, C.;
Fabrizio, M.; Faigler, S.; Fedorets, G.; Fernique, P.; Fienga, A.;
Fournier, Y.; Fouron, C.; Fragkoudi, F.; Gai, M.; Garcia-Gutierrez,
A.; Garcia-Reinaldos, M.; García-Torres, M.; Garofalo, A.; Gavel,
A.; Gavras, P.; Gerlach, E.; Geyer, R.; Giacobbe, P.; Gilmore, G.;
Girona, S.; Giuffrida, G.; Gomel, R.; Gomez, A.; González-Núñez,
J.; González-Santamaría, I.; González-Vidal, J. J.; Granvik,
M.; Guillout, P.; Guiraud, J.; Gutiérrez-Sánchez, R.; Guy, L. P.;
Hatzidimitriou, D.; Hauser, M.; Haywood, M.; Helmer, A.; Helmi, A.;
Sarmiento, M. H.; Hidalgo, S. L.; Hilger, T.; Hładczuk, N.; Hobbs,
D.; Holland, G.; Huckle, H. E.; Jasniewicz, G.; Jean-Antoine Piccolo,
A.; Jiménez-Arranz, Ó.; Jorissen, A.; Juaristi Campillo, J.; Julbe,
F.; Karbevska, L.; Kervella, P.; Kontizas, M.; Kordopatis, G.; Korn,
A. J.; Kóspál, Á; Kostrzewa-Rutkowska, Z.; Kruszyńska, K.; Kun, M.;
Laizeau, P.; Lambert, S.; Lanza, A. F.; Lasne, Y.; Le Campion, J. -F.;
Lebreton, Y.; Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi,
I.; Liao, S.; Licata, E. L.; Lindstrøm, H. E. P.; Lister, T. A.;
Livanou, E.; Lorca, A.; Loup, C.; Madrero Pardo, P.; Magdaleno Romeo,
A.; Managau, S.; Mann, R. G.; Manteiga, M.; Marchant, J. M.; Marconi,
M.; Marcos, J.; Marcos Santos, M. M. S.; Marín Pina, D.; Marinoni,
S.; Marocco, F.; Polo, L. Martin; Martín-Fleitas, J. M.; Marton, G.;
Mary, N.; Masip, A.; Massari, D.; Mastrobuono-Battisti, A.; Mazeh,
T.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Mints,
A.; Molina, D.; Molinaro, R.; Molnár, L.; Monari, G.; Monguió,
M.; Montegriffo, P.; Montero, A.; Mor, R.; Mora, A.; Morbidelli, R.;
Morel, T.; Morris, D.; Murphy, C. P.; Musella, I.; Nagy, Z.; Noval,
L.; Ocaña, F.; Ogden, A.; Ordenovic, C.; Osinde, J. O.; Pagani, C.;
Pagano, I.; Palaversa, L.; Palicio, P. A.; Pallas-Quintela, L.; Panahi,
A.; Payne-Wardenaar, S.; Peñalosa Esteller, X.; Penttilä, A.; Pichon,
B.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Prša,
A.; Pulone, L.; Racero, E.; Ragaini, S.; Rainer, M.; Raiteri, C. M.;
Rambaux, N.; Ramos-Lerate, M.; Re Fiorentin, P.; Regibo, S.; Richards,
P. J.; Rios Diaz, C.; Riva, A.; Rix, H. -W.; Rixon, G.; Robichon, N.;
Robin, A. C.; Robin, C.; Roelens, M.; Rogues, H. R. O.; Rohrbasser,
L.; Rowell, N.; Royer, F.; Ruz Mieres, D.; Rybicki, K. A.; Sadowski,
G.; Sáez Núñez, A.; Sagristà Sellés, A.; Sahlmann, J.; Salguero,
E.; Samaras, N.; Sanchez Gimenez, V.; Sanna, N.; Santoveña, R.;
Sarasso, M.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.;
Ségransan, D.; Semeux, D.; Shahaf, S.; Siddiqui, H. I.; Siebert,
A.; Siltala, L.; Silvelo, A.; Slezak, E.; Slezak, I.; Smart, R. L.;
Snaith, O. N.; Solano, E.; Solitro, F.; Souami, D.; Souchay, J.;
Spagna, A.; Spina, L.; Spoto, F.; Steele, I. A.; Steidelmüller,
H.; Stephenson, C. A.; Süveges, M.; Surdej, J.; Szabados, L.;
Szegedi-Elek, E.; Taris, F.; Taylo, M. B.; Teixeira, R.; Tolomei,
L.; Tonello, N.; Torra, F.; Torra, J.; Torralba Elipe, G.; Trabucchi,
M.; Tsounis, A. T.; Turon, C.; Ulla, A.; Unger, N.; Vaillant, M. V.;
van Dillen, E.; van Reeven, W.; Vanel, O.; Vecchiato, A.; Viala, Y.;
Vicente, D.; Voutsinas, S.; Weiler, M.; Wevers, T.; Wyrzykowski, L.;
Yoldas, A.; Yvard, P.; Zhao, H.; Zorec, J.; Zucker, S.; Zwitter, T.
2022arXiv220606207G Altcode:
With the most recent Gaia data release the number of sources with
complete 6D phase space information (position and velocity) has
increased to well over 33 million stars, while stellar astrophysical
parameters are provided for more than 470 million sources, in addition
to the identification of over 11 million variable stars. Using the
astrophysical parameters and variability classifications provided
in Gaia DR3, we select various stellar populations to explore and
identify non-axisymmetric features in the disc of the Milky Way in
both configuration and velocity space. Using more about 580 thousand
sources identified as hot OB stars, together with 988 known open
clusters younger than 100 million years, we map the spiral structure
associated with star formation 4-5 kpc from the Sun. We select over 2800
Classical Cepheids younger than 200 million years, which show spiral
features extending as far as 10 kpc from the Sun in the outer disc. We
also identify more than 8.7 million sources on the red giant branch
(RGB), of which 5.7 million have line-of-sight velocities, allowing
the velocity field of the Milky Way to be mapped as far as 8 kpc from
the Sun, including the inner disc. The spiral structure revealed by
the young populations is consistent with recent results using Gaia
EDR3 astrometry and source lists based on near infrared photometry,
showing the Local (Orion) arm to be at least 8 kpc long, and an outer
arm consistent with what is seen in HI surveys, which seems to be a
continuation of the Perseus arm into the third quadrant. Meanwhile,
the subset of RGB stars with velocities clearly reveals the large scale
kinematic signature of the bar in the inner disc, as well as evidence
of streaming motions in the outer disc that might be associated with
spiral arms or bar resonances. (abridged)
---------------------------------------------------------
Title: Gaia Data Release 3: The extragalactic content
Authors: Gaia Collaboration; Bailer-Jones, C. A. L.; Teyssier, D.;
Delchambre, L.; Ducourant, C.; Garabato, D.; Hatzidimitriou, D.;
Klioner, S. A.; Rimoldini, L.; Bellas-Velidis, I.; Carballo, R.;
Carnerero, M. I.; Diener, C.; Fouesneau, M.; Galluccio, L.; Gavras,
P.; Krone-Martins, A.; Raiteri, C. M.; Teixeira, R.; Brown, A. G. A.;
Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.; Arenou, F.; Babusiaux,
C.; Biermann, M.; Creevey, O. L.; Evans, D. W.; Eyer, L.; Guerra,
R.; Hutton, A.; Jordi, C.; Lammers, U. L.; Lindegren, L.; Luri, X.;
Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.; Sartoretti, P.;
Soubiran, C.; Tanga, P.; Walton, N. A.; Bastian, U.; Drimmel, R.;
Jansen, F.; Katz, D.; Lattanzi, M. G.; van Leeuwen, F.; Bakker, J.;
Cacciari, C.; Castañeda, J.; De Angeli, F.; Fabricius, C.; Frémat,
Y.; Guerrier, A.; Heiter, U.; Masana, E.; Messineo, R.; Mowlavi, N.;
Nicolas, C.; Nienartowicz, K.; Pailler, F.; Panuzzo, P.; Riclet, F.;
Roux, W.; Seabroke, G. M.; Sordo, R.; Thévenin, F.; Gracia-Abril, G.;
Portell, J.; Altmann, M.; Andrae, R.; Audard, M.; Benson, K.; Berthier,
J.; Blomme, R.; Burgess, P. W.; Busonero, D.; Busso, G.; Cánovas,
H.; Carry, B.; Cellino, A.; Cheek, N.; Clementini, G.; Damerdji,
Y.; Davidson, M.; de Teodoro, P.; Nuñez Campos, M.; Dell'Oro, A.;
Esquej, P.; Fernández-Hernández, J.; Fraile, E.; García-Lario, P.;
Gosset, E.; Haigron, R.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Holl, B.;
Janßen, K.; Jevardat de Fombelle, G.; Jordan, S.; Lanzafame, A. C.;
Löffler, W.; Marchal, O.; Marrese, P. M.; Moitinho, A.; Muinonen,
K.; Osborne, P.; Pancino, E.; Pauwels, T.; Recio-Blanco, A.; Reylé,
C.; Riello, M.; Roegiers, T.; Rybizki, J.; Sarro, L. M.; Siopis, C.;
Smith, M.; Sozzetti, A.; Utrilla, E.; van Leeuwen, M.; Abbas, U.;
Ábrahám, P.; Abreu Aramburu, A.; Aerts, C.; Aguado, J. J.; Ajaj,
M.; Aldea-Montero, F.; Altavilla, G.; Álvarez, M. A.; Alves, J.;
Anderson, R. I.; Anglada Varela, E.; Antoja, T.; Baines, D.; Baker,
S. G.; Balaguer-Núñez, L.; Balbinot, E.; Balog, Z.; Barache, C.;
Barbato, D.; Barros, M.; Barstow, M. A.; Bartolomé, S.; Bassilana,
J. -L.; Bauchet, N.; Becciani, U.; Bellazzini, M.; Berihuete, A.;
Bernet, M.; Bertone, S.; Bianchi, L.; Binnenfeld, A.; Blanco-Cuaresma,
S.; Boch, T.; Bombrun, A.; Bossini, D.; Bouquillon, S.; Bragaglia, A.;
Bramante, L.; Breedt, E.; Bressan, A.; Brouillet, N.; Brugaletta, E.;
Bucciarelli, B.; Burlacu, A.; Butkevich, A. G.; Buzzi, R.; Caffau,
E.; Cancelliere, R.; Cantat-Gaudin, T.; Carlucci, T.; Carrasco,
J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard, A.; Chaoul,
L.; Charlot, P.; Chemin, L.; Chiaramida, V.; Chiavassa, A.; Chornay,
N.; Comoretto, G.; Contursi, G.; Cooper, W. J.; Cornez, T.; Cowell,
S.; Crifo, F.; Cropper, M.; Crosta, M.; Crowley, C.; Dafonte, C.;
Dapergolas, A.; David, P.; de Laverny, P.; De Luise, F.; De March,
R.; De Ridder, J.; de Souza, R.; de Torres, A.; del Peloso, E. F.;
del Pozo, E.; Delbo, M.; Delgado, A.; Delisle, J. -B.; Demouchy, C.;
Dharmawardena, T. E.; Diakite, S.; Distefano, E.; Dolding, C.; Enke,
H.; Fabre, C.; Fabrizio, M.; Faigler, S.; Fedorets, G.; Fernique,
P.; Figueras, F.; Fournier, Y.; Fouron, C.; Fragkoudi, F.; Gai,
M.; Garcia-Gutierrez, A.; Garcia-Reinaldos, M.; García-Torres, M.;
Garofalo, A.; Gavel, A.; Gerlach, E.; Geyer, R.; Giacobbe, P.; Gilmore,
G.; Girona, S.; Giuffrida, G.; Gomel, R.; Gomez, A.; González-Núñez,
J.; González-Santamaría, I.; González-Vidal, J. J.; Granvik,
M.; Guillout, P.; Guiraud, J.; Gutiérrez-Sánchez, R.; Guy, L. P.;
Hauser, M.; Haywood, M.; Helmer, A.; Helmi, A.; Sarmiento, M. H.;
Hidalgo, S. L.; Hładczuk, N.; Hobbs, D.; Holland, G.; Huckle, H. E.;
Jardine, K.; Jasniewicz, G.; Jean-Antoine Piccolo, A.; Jiménez-Arranz,
Ó.; Juaristi Campillo, J.; Julbe, F.; Karbevska, L.; Kervella, P.;
Khanna, S.; Kontizas, M.; Kordopatis, G.; Korn, A. J.; Kóspál,
Á; Kostrzewa-Rutkowska, Z.; Kruszyńska, K.; Kun, M.; Laizeau, P.;
Lambert, S.; Lanza, A. F.; Lasne, Y.; Le Campion, J. -F.; Lebreton,
Y.; Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Liao,
S.; Licata, E. L.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.;
Lobel, A.; Lorca, A.; Loup, C.; Madrero Pardo, P.; Magdaleno Romeo,
A.; Managau, S.; Mann, R. G.; Manteiga, M.; Marchant, J. M.; Marconi,
M.; Marcos, J.; Marcos Santos, M. M. S.; Marín Pina, D.; Marinoni, S.;
Marocco, F.; Marshall, D. J.; Polo, L. Martin; Martín-Fleitas, J. M.;
Marton, G.; Mary, N.; Masip, A.; Massari, D.; Mastrobuono-Battisti,
A.; Mazeh, T.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar,
N. R.; Mints, A.; Molina, D.; Molinaro, R.; Molnár, L.; Monari,
G.; Monguió, M.; Montegriffo, P.; Montero, A.; Mor, R.; Mora, A.;
Morbidelli, R.; Morel, T.; Morris, D.; Muraveva, T.; Murphy, C. P.;
Musella, I.; Nagy, Z.; Noval, L.; Ocaña, F.; Ogden, A.; Ordenovic,
C.; Osinde, J. O.; Pagani, C.; Pagano, I.; Palaversa, L.; Palicio,
P. A.; Pallas-Quintela, L.; Panahi, A.; Payne-Wardenaar, S.; Peñalosa
Esteller, X.; Penttilä, A.; Pichon, B.; Piersimoni, A. M.; Pineau,
F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Prša, A.; Pulone, L.;
Racero, E.; Ragaini, S.; Rainer, M.; Ramos, P.; Ramos-Lerate, M.; Re
Fiorentin, P.; Regibo, S.; Richards, P. J.; Rios Diaz, C.; Ripepi, V.;
Riva, A.; Rix, H. -W.; Rixon, G.; Robichon, N.; Robin, A. C.; Robin,
C.; Roelens, M.; Rogues, H. R. O.; Rohrbasser, L.; Romero-Gómez, M.;
Rowell, N.; Royer, F.; Ruz Mieres, D.; Rybicki, K. A.; Sadowski, G.;
Sáez Núñez, A.; Sagristà Sellés, A.; Sahlmann, J.; Salguero, E.;
Samaras, N.; Sanchez Gimenez, V.; Sanna, N.; Santoveña, R.; Sarasso,
M.; Schultheis, M. S.; Sciacca, E.; Segol, M.; Segovia, J. C.;
Ségransan, D.; Semeux, D.; Shahaf, S.; Siddiqui, H. I.; Siebert,
A.; Siltala, L.; Silvelo, A.; Slezak, E.; Slezak, I.; Smart, R. L.;
Snaith, O. N.; Solano, E.; Solitro, F.; Souami, D.; Souchay, J.;
Spagna, A.; Spina, L.; Spoto, F.; Steele, I. A.; Steidelmüller,
H.; Stephenson, C. A.; Süveges, M.; Surdej, J.; Szabados, L.;
Szegedi-Elek, E.; Taris, F.; Taylor, M. B.; Tolomei, L.; Tonello,
N.; Torra, F.; Torra, J.; Torralba Elipe, G.; Trabucchi, M.; Tsounis,
A. T.; Turon, C.; Ulla, A.; Unger, N.; Vaillant, M. V.; van Dillen,
E.; van Reeven, W.; Vanel, O.; Vecchiato, A.; Viala, Y.; Vicente, D.;
Voutsinas, S.; Weiler, M.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.;
Yvard, P.; Zhao, H.; Zorec, J.; Zucker, S.; Zwitter, T.
2022arXiv220605681G Altcode:
The Gaia Galactic survey mission is designed and optimized to obtain
astrometry, photometry, and spectroscopy of nearly two billion stars in
our Galaxy. Yet as an all-sky multi-epoch survey, Gaia also observes
several million extragalactic objects down to a magnitude of G~21
mag. Due to the nature of the Gaia onboard selection algorithms,
these are mostly point-source-like objects. Using data provided by
the satellite, we have identified quasar and galaxy candidates via
supervised machine learning methods, and estimate their redshifts using
the low resolution BP/RP spectra. We further characterise the surface
brightness profiles of host galaxies of quasars and of galaxies from
pre-defined input lists. Here we give an overview of the processing
of extragalactic objects, describe the data products in Gaia DR3,
and analyse their properties. Two integrated tables contain the main
results for a high completeness, but low purity (50-70%), set of
6.6 million candidate quasars and 4.8 million candidate galaxies. We
provide queries that select purer sub-samples of these containing 1.9
million probable quasars and 2.9 million probable galaxies (both 95%
purity). We also use high quality BP/RP spectra of 43 thousand high
probability quasars over the redshift range 0.05-4.36 to construct a
composite quasar spectrum spanning restframe wavelengths from 72-100 nm.
---------------------------------------------------------
Title: Gaia Data Release 3: Reflectance spectra of Solar System
small bodies
Authors: Gaia Collaboration; Galluccio, L.; Delbo, M.; De Angeli, F.;
Pauwels, T.; Tanga, P.; Mignard, F.; Cellino, A.; Brown, A. G. A.;
Muinonen, K.; Penttila, A.; Jordan, S.; Vallenari, A.; Prusti,
T.; de Bruijne, J. H. J.; Arenou, F.; Babusiaux, C.; Biermann, M.;
Creevey, O. L.; Ducourant, C.; Evans, D. W.; Eyer, L.; Guerra, R.;
Hutton, A.; Jordi, C.; Klioner, S. A.; Lammers, U. L.; Lindegren,
L.; Luri, X.; Panem, C.; Pourbaix, D.; Randich, S.; Sartoretti, P.;
Soubiran, C.; Walton, N. A.; Bailer-Jones, C. A. L.; Bastian, U.;
Drimmel, R.; Jansen, F.; Katz, D.; Lattanzi, M. G.; van Leeuwen, F.;
Bakker, J.; Cacciari, C.; Castaneda, J.; Fabricius, C.; Fouesneau,
M.; Frémat, Y.; Guerrier, A.; Heiter, U.; Masana, E.; Messineo, R.;
Mowlavi, N.; Nicolas, C.; Nienartowicz, K.; Pailler, F.; Panuzzo,
P.; Riclet, F.; Roux, W.; Seabroke, G. M.; Sordo, R.; Thévenin, F.;
Gracia-Abril, G.; Portell, J.; Teyssier, D.; Altmann, M.; Andrae, R.;
Audard, M.; Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme, R.;
Burgess, P. W.; Busonero, D.; Busso, G.; Cánovas, H.; Carry, B.;
Cheek, N.; Clementini, G.; Damerdji, Y.; Davidson, M.; de Teodoro,
P.; Nunez Campos, M.; Delchambre, L.; Dell Oro, A.; Esquej, P.;
Fernández-Hernández, J.; Fraile, E.; Garabato, D.; García-Lario,
P.; Gosset, E.; Haigron, R.; Halbwachs, J. -L.; Hambly, N. C.;
Harrison, D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.;
Holl, B.; Janssen, K.; Jevardat de Fombelle, G.; Krone-Martins, A.;
Lanzafame, A. C.; Löffler, W.; Marchal, O.; Marrese, P. M.; Moitinho,
A.; Osborne, P.; Pancino, E.; Recio-Blanco, A.; Reylé, C.; Riello,
M.; Rimoldini, L.; Roegiers, T.; Rybizki, J.; Sarro, L. M.; Siopis,
C.; Smith, M.; Sozzetti, A.; Utrilla, E.; van Leeuwen, M.; Abbas, U.;
Ábrahám, P.; Abreu Aramburu, A.; Aerts, C.; Aguado, J. J.; Ajaj,
M.; Aldea-Montero, F.; Altavilla, G.; Álvarez, M. A.; Alves, J.;
Anderson, R. I.; Anglada Varela, E.; Antoja, T.; Baines, D.; Baker,
S. G.; Balaguer-Núnez, L.; Balbinot, E.; Balog, Z.; Barache, C.;
Barbato, D.; Barros, M.; Barstow, M. A.; Bartolomé, S.; Bassilana,
J. -L.; Bauchet, N.; Becciani, U.; Bellazzini, M.; Berihuete, A.;
Bernet, M.; Bertone, S.; Bianchi, L.; Binnenfeld, A.; Blanco-Cuaresma,
S.; Boch, T.; Bombrun, A.; Bossini, D.; Bouquillon, S.; Bragaglia, A.;
Bramante, L.; Breedt, E.; Bressan, A.; Brouillet, N.; Brugaletta, E.;
Bucciarelli, B.; Burlacu, A.; Butkevich, A. G.; Buzzi, R.; Caffau,
E.; Cancelliere, R.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.;
Carnerero, M. I.; Carrasco, J. M.; Casamiquela, L.; Castellani, M.;
Castro-Ginard, A.; Chaoul, L.; Charlot, P.; Chemin, L.; Chiaramida,
V.; Chiavassa, A.; Chornay, N.; Comoretto, G.; Contursi, G.; Cooper,
W. J.; Cornez, T.; Cowell, S.; Crifo, F.; Cropper, M.; Crosta, M.;
Crowley, C.; Dafonte, C.; Dapergolas, A.; David, P.; de Laverny, P.;
De Luise, F.; De March, R.; De Ridder, J.; de Souza, R.; de Torres,
A.; del Peloso, E. F.; del Pozo, E.; Delgado, A.; Delisle, J. -B.;
Demouchy, C.; Dharmawardena, T. E.; Diakite, S.; Diener, C.; Distefano,
E.; Dolding, C.; Enke, H.; Fabre, C.; Fabrizio, M.; Faigler, S.;
Fedorets, G.; Fernique, P.; Figueras, F.; Fournier, Y.; Fouron, C.;
Fragkoudi, F.; Gai, M.; Garcia-Gutierrez, A.; Garcia-Reinaldos, M.;
García-Torres, M.; Garofalo, A.; Gavel, A.; Gavras, P.; Gerlach,
E.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona, S.; Giuffrida, G.;
Gomel, R.; Gomez, A.; González-Núnez, J.; González-Santamaría,
I.; González-Vidal, J. J.; Granvik, M.; Guillout, P.; Guiraud, J.;
Gutiérrez-Sánchez, R.; Guy, L. P.; Hatzidimitriou, D.; Hauser,
M.; Haywood, M.; Helmer, A.; Helmi, A.; Sarmiento, M. H.; Hidalgo,
S. L.; Hadczuk, N.; Hobbs, D.; Holland, G.; Huckle, H. E.; Jardine,
K.; Jasniewicz, G.; Jean-Antoine Piccolo, A.; Jiménez-Arranz, Ó.;
Juaristi Campillo, J.; Julbe, F.; Karbevska, L.; Kervella, P.; Khanna,
S.; Kordopatis, G.; Korn, A. J.; Kospál, A; Kostrzewa-Rutkowska,
Z.; Kruszynska, K.; Kun, M.; Laizeau, P.; Lambert, S.; Lanza,
A. F.; Lasne, Y.; Le Campion, J. -F.; Lebreton, Y.; Lebzelter, T.;
Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Liao, S.; Licata, E. L.;
Lindstrom, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; Lorca,
A.; Loup, C.; Madrero Pardo, P.; Magdaleno Romeo, A.; Managau, S.;
Mann, R. G.; Manteiga, M.; Marchant, J. M.; Marconi, M.; Marcos, J.;
Marcos Santos, M. M. S.; Marín Pina, D.; Marinoni, S.; Marocco, F.;
Marshall, D. J.; Polo, L. Martin; Martín-Fleitas, J. M.; Marton, G.;
Mary, N.; Masip, A.; Massari, D.; Mastrobuono-Battisti, A.; Mazeh,
T.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Mints,
A.; Molina, D.; Molinaro, R.; Molnár, L.; Monari, G.; Monguió, M.;
Montegriffo, P.; Montero, A.; Mor, R.; Mora, A.; Morbidelli, R.; Morel,
T.; Morris, D.; Muraveva, T.; Murphy, C. P.; Musella, I.; Nagy, Z.;
Noval, L.; Ocana, F.; Ogden, A.; Ordenovic, C.; Osinde, J. O.; Pagani,
C.; Pagano, I.; Palaversa, L.; Palicio, P. A.; Pallas-Quintela, L.;
Panahi, A.; Payne-Wardenaar, S.; Penalosa Esteller, X.; Petit, J. -M.;
Pichon, B.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.;
Poggio, E.; Prsa, A.; Pulone, L.; Racero, E.; Ragaini, S.; Rainer, M.;
Raiteri, C. M.; Ramos, P.; Ramos-Lerate, M.; Re Fiorentin, P.; Regibo,
S.; Richards, P. J.; Rios Diaz, C.; Ripepi, V.; Riva, A.; Rix, H. -W.;
Rixon, G.; Robichon, N.; Robin, A. C.; Robin, C.; Roelens, M.; Rogues,
H. R. O.; Rohrbasser, L.; Romero-Gómez, M.; Rowell, N.; Royer, F.; Ruz
Mieres, D.; Rybicki, K. A.; Sadowski, G.; Sáez Núnez, A.; Sagristà
Sellés, A.; Sahlmann, J.; Salguero, E.; Samaras, N.; Sanchez Gimenez,
V.; Sanna, N.; Santovena, R.; Sarasso, M.; Schultheis, M.; Sciacca,
E.; Segol, M.; Segovia, J. C.; Ségransan, D.; Semeux, D.; Shahaf,
S.; Siddiqui, H. I.; Siebert, A.; Siltala, L.; Silvelo, A.; Slezak,
E.; Slezak, I.; Smart, R. L.; Snaith, O. N.; Solano, E.; Solitro,
F.; Souami, D.; Souchay, J.; Spagna, A.; Spina, L.; Spoto, F.;
Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.; Süveges,
M.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.; Taris, F.; Taylor,
M. B.; Teixeira, R.; Tolomei, L.; Tonello, N.; Torra, F.; Torra, J.;
Torralba Elipe, G.; Trabucchi, M.; Tsounis, A. T.; Turon, C.; Ulla,
A.; Unger, N.; Vaillant, M. V.; van Dillen, E.; van Reeven, W.; Vanel,
O.; Vecchiato, A.; Viala, Y.; Vicente, D.; Voutsinas, S.; Weiler, M.;
Wevers, T.; Wyrzykowski, L.; Yoldas, A.; Yvard, P.; Zhao, H.; Zorec,
J.; Zucker, S.; Zwitter, T.
2022arXiv220612174G Altcode:
The Gaia mission of the European Space Agency (ESA) has been routinely
observing Solar System objects (SSOs) since the beginning of its
operations in August 2014. The Gaia data release three (DR3) includes,
for the first time, the mean reflectance spectra of a selected sample of
60 518 SSOs, primarily asteroids, observed between August 5, 2014, and
May 28, 2017. Each reflectance spectrum was derived from measurements
obtained by means of the Blue and Red photometers (BP/RP), which were
binned in 16 discrete wavelength bands. We describe the processing
of the Gaia spectral data of SSOs, explaining both the criteria used
to select the subset of asteroid spectra published in Gaia DR3,
and the different steps of our internal validation procedures. In
order to further assess the quality of Gaia SSO reflectance spectra,
we carried out external validation against SSO reflectance spectra
obtained from ground-based and space-borne telescopes and available
in the literature. For each selected SSO, an epoch reflectance was
computed by dividing the calibrated spectrum observed by the BP/RP
at each transit on the focal plane by the mean spectrum of a solar
analogue. The latter was obtained by averaging the Gaia spectral
measurements of a selected sample of stars known to have very similar
spectra to that of the Sun. Finally, a mean of the epoch reflectance
spectra was calculated in 16 spectral bands for each SSO. The agreement
between Gaia mean reflectance spectra and those available in the
literature is good for bright SSOs, regardless of their taxonomic
spectral class. We identify an increase in the spectral slope of S-type
SSOs with increasing phase angle. Moreover, we show that the spectral
slope increases and the depth of the 1 um absorption band decreases
for increasing ages of S-type asteroid families.
---------------------------------------------------------
Title: Gaia Data Release 3: A Golden Sample of Astrophysical
Parameters
Authors: Gaia Collaboration; Creevey, O. L.; Sarro, L. M.; Lobel, A.;
Pancino, E.; Andrae, R.; Smart, R. L.; Clementini, G.; Heiter, U.;
Korn, A. J.; Fouesneau, M.; Frémat, Y.; De Angeli, F.; Vallenari, A.;
Harrison, D. L.; Thévenin, F.; Reylé, C.; Sordo, R.; Garofalo, A.;
Brown, A. G. A.; Eyer, L.; Prusti, T.; de Bruijne, J. H. J.; Arenou,
F.; Babusiaux, C.; Biermann, M.; Ducourant, C.; Evans, D. W.; Guerra,
R.; Hutton, A.; Jordi, C.; Klioner, S. A.; Lammers, U. L.; Lindegren,
L.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.;
Sartoretti, P.; Soubiran, C.; Tanga, P.; Walton, N. A.; Bailer-Jones,
C. A. L.; Bastian, U.; Drimmel, R.; Jansen, F.; Katz, D.; Lattanzi,
M. G.; van Leeuwen, F.; Bakker, J.; Cacciari, C.; Castañeda, J.;
Fabricius, C.; Galluccio, L.; Guerrier, A.; Masana, E.; Messineo, R.;
Mowlavi, N.; Nicolas, C.; Nienartowicz, K.; Pailler, F.; Panuzzo, P.;
Riclet, F.; Roux, W.; Seabroke, G. M.; Gracia-Abril, G.; Portell, J.;
Teyssier, D.; Altmann, M.; Audard, M.; Bellas-Velidis, I.; Benson,
K.; Berthier, J.; Blomme, R.; Burgess, P. W.; Busonero, D.; Busso,
G.; Cánovas, H.; Carry, B.; Cellino, A.; Cheek, N.; Damerdji, Y.;
Davidson, M.; de Teodoro, P.; Nuñez Campos, M.; Delchambre, L.;
Dell'Oro, A.; Esquej, P.; Fernández-Hernández, J.; Fraile, E.;
Garabato, D.; García-Lario, P.; Gosset, E.; Haigron, R.; Halbwachs,
J. -L.; Hambly, N. C.; Hernández, J.; Hestroffer, D.; Hodgkin,
S. T.; Holl, B.; Janßen, K.; Jevardat de Fombelle, G.; Jordan,
S.; Krone-Martins, A.; Lanzafame, A. C.; Löffler, W.; Marchal, O.;
Marrese, P. M.; Moitinho, A.; Muinonen, K.; Osborne, P.; Pauwels, T.;
Recio-Blanco, A.; Riello, M.; Rimoldini, L.; Roegiers, T.; Rybizki,
J.; Siopis, C.; Smith, M.; Sozzetti, A.; Utrilla, E.; van Leeuwen,
M.; Abbas, U.; Ábrahám, P.; Abreu Aramburu, A.; Aerts, C.; Aguado,
J. J.; Ajaj, M.; Aldea-Montero, F.; Altavilla, G.; Álvarez, M. A.;
Alves, J.; Anders, F.; Anderson, R. I.; Anglada Varela, E.; Antoja, T.;
Baines, D.; Baker, S. G.; Balaguer-Núñez, L.; Balbinot, E.; Balog,
Z.; Barache, C.; Barbato, D.; Barros, M.; Barstow, M. A.; Bartolomé,
S.; Bassilana, J. -L.; Bauchet, N.; Becciani, U.; Bellazzini, M.;
Berihuete, A.; Bernet, M.; Bertone, S.; Bianchi, L.; Binnenfeld, A.;
Blanco-Cuaresma, S.; Boch, T.; Bombrun, A.; Bossini, D.; Bouquillon,
S.; Bragaglia, A.; Bramante, L.; Breedt, E.; Bressan, A.; Brouillet,
N.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.; Butkevich, A. G.;
Buzzi, R.; Caffau, E.; Cancelliere, R.; Cantat-Gaudin, T.; Carballo,
R.; Carlucci, T.; Carnerero, M. I.; Carrasco, J. M.; Casamiquela,
L.; Castellani, M.; Castro-Ginard, A.; Chaoul, L.; Charlot, P.;
Chemin, L.; Chiaramida, V.; Chiavassa, A.; Chornay, N.; Comoretto,
G.; Contursi, G.; Cooper, W. J.; Cornez, T.; Cowell, S.; Crifo, F.;
Cropper, M.; Crosta, M.; Crowley, C.; Dafonte, C.; Dapergolas, A.;
David, P.; de Laverny, P.; De Luise, F.; De March, R.; De Ridder, J.;
de Souza, R.; de Torres, A.; del Peloso, E. F.; del Pozo, E.; Delbo,
M.; Delgado, A.; Delisle, J. -B.; Demouchy, C.; Dharmawardena, T. E.;
Di Matteo, P.; Diakite, S.; Diener, C.; Distefano, E.; Dolding, C.;
Enke, H.; Fabre, C.; Fabrizio, M.; Faigler, S.; Fedorets, G.; Fernique,
P.; Figueras, F.; Fournier, Y.; Fouron, C.; Fragkoudi, F.; Gai, M.;
Garcia-Gutierrez, A.; Garcia-Reinaldos, M.; García-Torres, M.; Gavel,
A.; Gavras, P.; Gerlach, E.; Geyer, R.; Giacobbe, P.; Gilmore, G.;
Girona, S.; Giuffrida, G.; Gomel, R.; Gomez, A.; González-Núñez,
J.; González-Santamaría, I.; González-Vidal, J. J.; Granvik, M.;
Guillout, P.; Guiraud, J.; Gutiérrez-Sánchez, R.; Guy, L. P.;
Hatzidimitriou, D.; Hauser, M.; Haywood, M.; Helmer, A.; Helmi,
A.; Sarmiento, M. H.; Hidalgo, S. L.; Hładczuk, N.; Hobbs, D.;
Holland, G.; Huckle, H. E.; Jardine, K.; Jasniewicz, G.; Jean-Antoine
Piccolo, A.; Jiménez-Arranz, Ó.; Juaristi Campillo, J.; Julbe, F.;
Karbevska, L.; Kervella, P.; Khanna, S.; Kordopatis, G.; Kóspál,
Á; Kostrzewa-Rutkowska, Z.; Kruszyńska, K.; Kun, M.; Laizeau, P.;
Lambert, S.; Lanza, A. F.; Lasne, Y.; Le Campion, J. -F.; Lebreton,
Y.; Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Liao,
S.; Licata, E. L.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.;
Lorca, A.; Loup, C.; Madrero Pardo, P.; Magdaleno Romeo, A.; Managau,
S.; Mann, R. G.; Manteiga, M.; Marchant, J. M.; Marconi, M.; Marcos,
J.; Marcos Santos, M. M. S.; Marín Pina, D.; Marinoni, S.; Marocco,
F.; Marshall, D. J.; Polo, L. Martin; Martín-Fleitas, J. M.; Marton,
G.; Mary, N.; Masip, A.; Massari, D.; Mastrobuono-Battisti, A.; Mazeh,
T.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Mints,
A.; Molina, D.; Molinaro, R.; Molnár, L.; Monari, G.; Monguió, M.;
Montegriffo, P.; Montero, A.; Mor, R.; Mora, A.; Morbidelli, R.; Morel,
T.; Morris, D.; Muraveva, T.; Murphy, C. P.; Musella, I.; Nagy, Z.;
Noval, L.; Ocaña, F.; Ogden, A.; Ordenovic, C.; Osinde, J. O.; Pagani,
C.; Pagano, I.; Palaversa, L.; Palicio, P. A.; Pallas-Quintela, L.;
Panahi, A.; Payne-Wardenaar, S.; Peñalosa Esteller, X.; Penttilä, A.;
Pichon, B.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.;
Poggio, E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.; Rainer,
M.; Raiteri, C. M.; Ramos, P.; Ramos-Lerate, M.; Re Fiorentin,
P.; Regibo, S.; Richards, P. J.; Rios Diaz, C.; Ripepi, V.; Riva,
A.; Rix, H. -W.; Rixon, G.; Robichon, N.; Robin, A. C.; Robin, C.;
Roelens, M.; Rogues, H. R. O.; Rohrbasser, L.; Romero-Gómez, M.;
Rowell, N.; Royer, F.; Ruz Mieres, D.; Rybicki, K. A.; Sadowski, G.;
Sáez Núñez, A.; Sagristà Sellés, A.; Sahlmann, J.; Salguero,
E.; Samaras, N.; Sanchez Gimenez, V.; Sanna, N.; Santoveña, R.;
Sarasso, M.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.;
Ségransan, D.; Semeux, D.; Shahaf, S.; Siddiqui, H. I.; Siebert,
A.; Siltala, L.; Silvelo, A.; Slezak, E.; Slezak, I.; Snaith, O. N.;
Solano, E.; Solitro, F.; Souami, D.; Souchay, J.; Spagna, A.; Spina,
L.; Spoto, F.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.;
Süveges, M.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.; Taris,
F.; Taylor, M. B.; Teixeira, R.; Tolomei, L.; Tonello, N.; Torra,
F.; Torra, J.; Torralba Elipe, G.; Trabucchi, M.; Tsounis, A. T.;
Turon, C.; Ulla, A.; Unger, N.; Vaillant, M. V.; van Dillen, E.;
van Reeven, W.; Vanel, O.; Vecchiato, A.; Viala, Y.; Vicente, D.;
Voutsinas, S.; Weiler, M.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.;
Yvard, P.; Zhao, H.; Zorec, J.; Zucker, S.; Zwitter, T.
2022arXiv220605870G Altcode:
Gaia Data Release 3 (DR3) provides a wealth of new data products for the
astronomical community to exploit, including astrophysical parameters
for a half billion stars. In this work we demonstrate the high
quality of these data products and illustrate their use in different
astrophysical contexts. We query the astrophysical parameter tables
along with other tables in Gaia DR3 to derive the samples of the stars
of interest. We validate our results by using the Gaia catalogue itself
and by comparison with external data. We have produced six homogeneous
samples of stars with high quality astrophysical parameters across
the HR diagram for the community to exploit. We first focus on three
samples that span a large parameter space: young massive disk stars
(~3M), FGKM spectral type stars (~3M), and UCDs (~20K). We provide
these sources along with additional information (either a flag or
complementary parameters) as tables that are made available in the
Gaia archive. We furthermore identify 15740 bone fide carbon stars,
5863 solar-analogues, and provide the first homogeneous set of stellar
parameters of the Spectro Photometric Standard Stars. We use a subset
of the OBA sample to illustrate its usefulness to analyse the Milky
Way rotation curve. We then use the properties of the FGKM stars to
analyse known exoplanet systems. We also analyse the ages of some
unseen UCD-companions to the FGKM stars. We additionally predict the
colours of the Sun in various passbands (Gaia, 2MASS, WISE) using the
solar-analogue sample.
---------------------------------------------------------
Title: Gaia Data Release 3: Hot-star radial velocities
Authors: Blomme, R.; Fremat, Y.; Sartoretti, P.; Guerrier, A.; Panuzzo,
P.; Katz, D.; Seabroke, G. M.; Thevenin, F.; Cropper, M.; Benson, K.;
Damerdji, Y.; Haigron, R.; Marchal, O.; Smith, M.; Baker, S.; Chemin,
L.; David, M.; Dolding, C.; Gosset, E.; Janssen, K.; Jasniewicz, G.;
Lobel, A.; Plum, G.; Samaras, N.; Snaith, O.; Soubiran, C.; Vanel,
O.; Zwitter, T.; Brouillet, N.; Caffau, E.; Crifo, F.; Fabre, C.;
Frakgoudi, F.; Huckle, H. E.; Jean-Antoine Piccolo, A.; Lasne, Y.;
Leclerc, N.; Mastrobuono-Battisti, A.; Royer, F.; Viala, Y.; Zorec, J.
2022arXiv220605486B Altcode:
The second Gaia data release, DR2, contained radial velocities of stars
with effective temperatures up to Teff = 6900 K. The third data release,
Gaia DR3, extends this up to Teff = 14,500 K. We derive the radial
velocities for hot stars (i.e. in the Teff = 6900 - 14,500 K range)
from data obtained with the Radial Velocity Spectrometer (RVS) on board
Gaia. The radial velocities were determined by the standard technique
of measuring the Doppler shift of a template spectrum that was compared
to the observed spectrum. The RVS wavelength range is very limited. The
proximity to and systematic blueward offset of the calcium infrared
triplet to the hydrogen Paschen lines in hot stars can result in a
systematic offset in radial velocity. For the hot stars, we developed
a specific code to improve the selection of the template spectrum,
thereby avoiding this systematic offset. With the improved code, and
with the correction we propose to the DR3 archive radial velocities,
we obtain values that agree with reference values to within 3 km/s (in
median). Because of the required S/N for applying the improved code,
the hot star radial velocities in DR3 are mostly limited to stars with
a magnitude in the RVS wavelength band <= 12 mag.
---------------------------------------------------------
Title: Gaia Data Release 3 Properties and validation of the radial
velocities
Authors: Katz, D.; Sartoretti, P.; Guerrier, A.; Panuzzo, P.; Seabroke,
G. M.; Thévenin, F.; Cropper, M.; Benson, K.; Blomme, R.; Haigron,
R.; Marchal, O.; Smith, M.; Baker, S.; Chemin, L.; Damerdji, Y.; David,
M.; Dolding, C.; Frémat, Y.; Gosset, E.; Janßen, K.; Jasniewicz, G.;
Lobel, A.; Plum, G.; Samaras, N.; Snaith, O.; Soubiran, C.; Vanel,
O.; Zwitter, T.; Antoja, T.; Arenou, F.; Babusiaux, C.; Brouillet,
N.; Caffau, E.; Di Matteo, P.; Fabre, C.; Fabricius, C.; Frakgoudi,
F.; Haywood, M.; Huckle, H. E.; Hottier, C.; Lasne, Y.; Leclerc, N.;
Mastrobuono-Battisti, A.; Royer, F.; Teyssier, D.; Zorec, J.; Crifo,
F.; Jean-Antoine Piccolo, A.; Turon, C.; Viala, Y.
2022arXiv220605902K Altcode:
Gaia Data Release 3 (Gaia DR3) contains the second release of the
combined radial velocities. It is based on the spectra collected during
the first 34 months of the nominal mission. The longer time baseline
and the improvements of the pipeline made it possible to push the
processing limit, from Grvs = 12 in Gaia DR2, to Grvs = 14 mag. In this
article, we describe the new functionalities implemented for Gaia DR3,
the quality filters applied during processing and post-processing and
the properties and performance of the published velocities. For Gaia
DR3, several functionalities were upgraded or added. (Abridged) Gaia
DR3 contains the combined radial velocities of 33 812 183 stars. With
respect to Gaia DR2, the interval of temperature has been expanded
from Teff \in [3600, 6750] K to Teff \in [3100, 14500] K for the
bright stars ( Grvs \leq 12 mag) and [3100, 6750] K for the fainter
stars. The radial velocities sample a significant part of the Milky
Way: they reach a few kilo-parsecs beyond the Galactic centre in the
disc and up to about 10-15 kpc vertically into the inner halo. The
median formal precision of the velocities is of 1.3 km/s at Grvs =
12 and 6.4 km/s at Grvs = 14 mag. The velocity zero point exhibits a
small systematic trend with magnitude starting around Grvs = 11 mag
and reaching about 400 m/s at Grvs = 14 mag. A correction formula
is provided, which can be applied to the published data. The Gaia
DR3 velocity scale is in satisfactory agreement with APOGEE, GALAH,
GES and RAVE, with systematic differences that mostly do not exceed
a few hundreds m/s. The properties of the radial velocities are also
illustrated with specific objects: open clusters, globular clusters as
well as the Large Magellanic Cloud (LMC). For example, the precision
of the data allows to map the line-of-sight rotational velocities of
the globular cluster 47 Tuc and of the LMC.
---------------------------------------------------------
Title: Gaia Data Release 3: Pulsations in main sequence OBAF-type
stars
Authors: Gaia Collaboration; De Ridder, J.; Ripepi, V.; Aerts, C.;
Palaversa, L.; Eyer, L.; Holl, B.; Audard, M.; Rimoldini, L.; Brown,
A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.; Arenou, F.;
Babusiaux, C.; Biermann, M.; Creevey, O. L.; Ducourant, C.; Evans,
D. W.; Guerra, R.; Hutton, A.; Jordi, C.; Klioner, S. A.; Lammers,
U. L.; Lindegren, L.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix,
D.; Randich, S.; Sartoretti, P.; Soubiran, C.; Tanga, P.; Walton,
N. A.; Bailer-Jones, C. A. L.; Bastian, U.; Drimmel, R.; Jansen, F.;
Katz, D.; Lattanzi, M. G.; van Leeuwen, F.; Bakker, J.; Cacciari, C.;
Castañeda, J.; De Angeli, F.; Fabricius, C.; Fouesneau, M.; Frémat,
Y.; Galluccio, L.; Guerrier, A.; Heiter, U.; Masana, E.; Messineo,
R.; Mowlavi, N.; Nicolas, C.; Nienartowicz, K.; Pailler, F.; Panuzzo,
P.; Riclet, F.; Roux, W.; Seabroke, G. M.; Sordo, R.; Thévenin, F.;
Gracia-Abril, G.; Portell, J.; Teyssier, D.; Altmann, M.; Andrae, R.;
Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme, R.; Burgess,
P. W.; Busonero, D.; Busso, G.; Cánovas, H.; Carry, B.; Cellino, A.;
Cheek, N.; Clementini, G.; Damerdji, Y.; Davidson, M.; de Teodoro,
P.; Nuñez Campos, M.; Delchambre, L.; Dell'Oro, A.; Esquej, P.;
Fernández-Hernández, J.; Fraile, E.; Garabato, D.; García-Lario, P.;
Gosset, E.; Haigron, R.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
D. L.; Hernández, J.; Hestroffer, D.; Hilger, T.; Hodgkin, S. T.;
Janßen, K.; Jevardat de Fombelle, G.; Jordan, S.; Krone-Martins, A.;
Lanzafame, A. C.; Löffler, W.; Marchal, O.; Marrese, P. M.; Moitinho,
A.; Muinonen, K.; Osborne, P.; Pancino, E.; Pauwels, T.; Recio-Blanco,
A.; Reylé, C.; Riello, M.; Roegiers, T.; Rybizki, J.; Sarro, L. M.;
Siopis, C.; Smith, M.; Sozzetti, A.; Utrilla, E.; van Leeuwen, M.;
Abbas, U.; Ábrahám, P.; Abreu Aramburu, A.; Aguado, J. J.; Ajaj,
M.; Aldea-Montero, F.; Altavilla, G.; Álvarez, M. A.; Alves, J.;
Anders, F.; Anderson, R. I.; Anglada Varela, E.; Antoja, T.; Baines,
D.; Baker, S. G.; Balaguer-Núñez, L.; Balbinot, E.; Balog, Z.;
Barache, C.; Barbato, D.; Barros, M.; Barstow, M. A.; Bartolomé,
S.; Bassilana, J. -L.; Bauchet, N.; Becciani, U.; Bellazzini, M.;
Berihuete, A.; Bernet, M.; Bertone, S.; Bianchi, L.; Binnenfeld, A.;
Blanco-Cuaresma, S.; Boch, T.; Bombrun, A.; Bossini, D.; Bouquillon,
S.; Bragaglia, A.; Bramante, L.; Breedt, E.; Bressan, A.; Brouillet,
N.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.; Butkevich, A. G.;
Buzzi, R.; Caffau, E.; Cancelliere, R.; Cantat-Gaudin, T.; Carballo,
R.; Carlucci, T.; Carnerero, M. I.; Carrasco, J. M.; Casamiquela,
L.; Castellani, M.; Castro-Ginard, A.; Chaoul, L.; Charlot, P.;
Chemin, L.; Chiaramida, V.; Chiavassa, A.; Chornay, N.; Comoretto,
G.; Contursi, G.; Cooper, W. J.; Cornez, T.; Cowell, S.; Crifo, F.;
Cropper, M.; Crosta, M.; Crowley, C.; Dafonte, C.; Dapergolas, A.;
David, P.; de Laverny, P.; De Luise, F.; De March, R.; de Souza, R.;
de Torres, A.; del Peloso, E. F.; del Pozo, E.; Delbo, M.; Delgado,
A.; Delisle, J. -B.; Demouchy, C.; Dharmawardena, T. E.; Diakite,
S.; Diener, C.; Distefano, E.; Dolding, C.; Enke, H.; Fabre, C.;
Fabrizio, M.; Faigler, S.; Fedorets, G.; Fernique, P.; Figueras, F.;
Fournier, Y.; Fouron, C.; Fragkoudi, F.; Gai, M.; Garcia-Gutierrez,
A.; Garcia-Reinaldos, M.; García-Torres, M.; Garofalo, A.; Gavel,
A.; Gavras, P.; Gerlach, E.; Geyer, R.; Giacobbe, P.; Gilmore, G.;
Girona, S.; Giuffrida, G.; Gomel, R.; Gomez, A.; González-Núñez,
J.; González-Santamaría, I.; González-Vidal, J. J.; Granvik,
M.; Guillout, P.; Guiraud, J.; Gutiérrez-Sánchez, R.; Guy, L. P.;
Hatzidimitriou, D.; Hauser, M.; Haywood, M.; Helmer, A.; Helmi, A.;
Sarmiento, M. H.; Hidalgo, S. L.; Hładczuk, N.; Hobbs, D.; Holland,
G.; Huckle, H. E.; Jardine, K.; Jasniewicz, G.; Jean-Antoine Piccolo,
A.; Jiménez-Arranz, Ó.; Juaristi Campillo, J.; Julbe, F.; Karbevska,
L.; Kervella, P.; Khanna, S.; Kordopatis, G.; Korn, A. J.; Kóspál,
Á; Kostrzewa-Rutkowska, Z.; Kruszyńska, K.; Kun, M.; Laizeau, P.;
Lambert, S.; Lanza, A. F.; Lasne, Y.; Le Campion, J. -F.; Lebreton,
Y.; Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Liao,
S.; Licata, E. L.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.;
Lobel, A.; Lorca, A.; Loup, C.; Madrero Pardo, P.; Magdaleno Romeo,
A.; Managau, S.; Mann, R. G.; Manteiga, M.; Marchant, J. M.; Marconi,
M.; Marcos, J.; Marcos Santos, M. M. S.; Marín Pina, D.; Marinoni, S.;
Marocco, F.; Marshall, D. J.; Polo, L. Martin; Martín-Fleitas, J. M.;
Marton, G.; Mary, N.; Masip, A.; Massari, D.; Mastrobuono-Battisti, A.;
Mazeh, T.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.;
Mints, A.; Molina, D.; Molinaro, R.; Molnár, L.; Monari, G.; Monguió,
M.; Montegriffo, P.; Montero, A.; Mor, R.; Mora, A.; Morbidelli,
R.; Morel, T.; Morris, D.; Muraveva, T.; Murphy, C. P.; Musella, I.;
Nagy, Z.; Noval, L.; Ocaña, F.; Ogden, A.; Ordenovic, C.; Osinde,
J. O.; Pagani, C.; Pagano, I.; Palicio, P. A.; Pallas-Quintela, L.;
Panahi, A.; Payne-Wardenaar, S.; Peñalosa Esteller, X.; Penttilä, A.;
Pichon, B.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.;
Poggio, E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.; Rainer, M.;
Raiteri, C. M.; Ramos, P.; Ramos-Lerate, M.; Re Fiorentin, P.; Regibo,
S.; Richards, P. J.; Rios Diaz, C.; Riva, A.; Rix, H. -W.; Rixon, G.;
Robichon, N.; Robin, A. C.; Robin, C.; Roelens, M.; Rogues, H. R. O.;
Rohrbasser, L.; Romero-Gómez, M.; Rowell, N.; Royer, F.; Ruz Mieres,
D.; Rybicki, K. A.; Sadowski, G.; Sáez Núñez, A.; Sagristà Sellés,
A.; Sahlmann, J.; Salguero, E.; Samaras, N.; Sanchez Gimenez, V.;
Sanna, N.; Santoveña, R.; Sarasso, M.; Schultheis, M.; Sciacca, E.;
Segol, M.; Segovia, J. C.; Ségransan, D.; Semeux, D.; Shahaf, S.;
Siddiqui, H. I.; Siebert, A.; Siltala, L.; Silvelo, A.; Slezak, E.;
Slezak, I.; Smart, R. L.; Snaith, O. N.; Solano, E.; Solitro, F.;
Souami, D.; Souchay, J.; Spagna, A.; Spina, L.; Spoto, F.; Steele,
I. A.; Steidelmüller, H.; Stephenson, C. A.; Süveges, M.; Surdej, J.;
Szabados, L.; Szegedi-Elek, E.; Taris, F.; Taylor, M. B.; Teixeira,
R.; Tolomei, L.; Tonello, N.; Torra, F.; Torra, J.; Torralba Elipe,
G.; Trabucchi, M.; Tsounis, A. T.; Turon, C.; Ulla, A.; Unger, N.;
Vaillant, M. V.; van Dillen, E.; van Reeven, W.; Vanel, O.; Vecchiato,
A.; Viala, Y.; Vicente, D.; Voutsinas, S.; Weiler, M.; Wevers, T.;
Wyrzykowski, Ł.; Yoldas, A.; Yvard, P.; Zhao, H.; Zorec, J.; Zucker,
S.; Zwitter, T.
2022arXiv220606075G Altcode:
The third Gaia data release provides photometric time series covering
34 months for about 10 million stars. For many of those stars, a
characterisation in Fourier space and their variability classification
are also provided. This paper focuses on intermediate- to high-mass
(IHM) main sequence pulsators M >= 1.3 Msun) of spectral types O,
B, A, or F, known as beta Cep, slowly pulsating B (SPB), delta Sct,
and gamma Dor stars. These stars are often multi-periodic and display
low amplitudes, making them challenging targets to analyse with sparse
time series. All datasets used in this analysis are part of the Gaia DR3
data release. The photometric time series were used to perform a Fourier
analysis, while the global astrophysical parameters necessary for
the empirical instability strips were taken from the Gaia DR3 gspphot
tables, and the vsini data were taken from the Gaia DR3 esphs tables. We
show that for nearby OBAF-type pulsators, the Gaia DR3 data are
precise and accurate enough to pinpoint them in the Hertzsprung-Russell
diagram. We find empirical instability strips covering broader regions
than theoretically predicted. In particular, our study reveals the
presence of fast rotating gravity-mode pulsators outside the strips,
as well as the co-existence of rotationally modulated variables inside
the strips as reported before in the literature. We derive an extensive
period-luminosity relation for delta Sct stars and provide evidence that
the relation features different regimes depending on the oscillation
period. Finally, we demonstrate how stellar rotation attenuates the
amplitude of the dominant oscillation mode of delta Sct stars.
---------------------------------------------------------
Title: Gaia Data Release 3: Stellar multiplicity, a teaser for the
hidden treasure
Authors: Gaia Collaboration; Arenou, F.; Babusiaux, C.; Barstow,
M. A.; Faigler, S.; Jorissen, A.; Kervella, P.; Mazeh, T.; Mowlavi,
N.; Panuzzo, P.; Sahlmann, J.; Shahaf, S.; Sozzetti, A.; Bauchet, N.;
Damerdji, Y.; Gavras, P.; Giacobbe, P.; Gosset, E.; Halbwachs, J. -L.;
Holl, B.; Lattanzi, M. G.; Leclerc, N.; Morel, T.; Pourbaix, D.; Re
Fiorentin, P.; Sadowski, G.; Ségransan, D.; Siopis, C.; Teyssier, D.;
Zwitter, T.; Planquart, L.; Brown, A. G. A.; Vallenari, A.; Prusti,
T.; de Bruijne, J. H. J.; Biermann, M.; Creevey, O. L.; Ducourant, C.;
Evans, D. W.; Eyer, L.; Guerra, R.; Hutton, A.; Jordi, C.; Klioner,
S. A.; Lammers, U. L.; Lindegren, L.; Luri, X.; Mignard, F.; Panem,
C.; Randich, S.; Sartoretti, P.; Soubiran, C.; Tanga, P.; Walton,
N. A.; Bailer-Jones, C. A. L.; Bastian, U.; Drimmel, R.; Jansen, F.;
Katz, D.; van Leeuwen, F.; Bakker, J.; Cacciari, C.; Castañeda, J.;
De Angeli, F.; Fabricius, C.; Fouesneau, M.; Frémat, Y.; Galluccio,
L.; Guerrier, A.; Heiter, U.; Masana, E.; Messineo, R.; Nicolas,
C.; Nienartowicz, K.; Pailler, F.; Riclet, F.; Roux, W.; Seabroke,
G. M.; Sordo, R.; Thévenin, F.; Gracia-Abril, G.; Portell, J.;
Altmann, M.; Andrae, R.; Audard, M.; Bellas-Velidis, I.; Benson,
K.; Berthier, J.; Blomme, R.; Burgess, P. W.; Busonero, D.; Busso,
G.; Cánovas, H.; Carry, B.; Cellino, A.; Cheek, N.; Clementini,
G.; Davidson, M.; de Teodoro, P.; Nuñez Campos, M.; Delchambre,
L.; Dell'Oro, A.; Esquej, P.; Fernández-Hernández, J.; Fraile,
E.; Garabato, D.; García-Lario, P.; Haigron, R.; Hambly, N. C.;
Harrison, D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.;
Janßen, K.; Jevardat de Fombelle, G.; Jordan, S.; Krone-Martins,
A.; Lanzafame, A. C.; Löffler, W.; Marchal, O.; Marrese, P. M.;
Moitinho, A.; Muinonen, K.; Osborne, P.; Pancino, E.; Pauwels, T.;
Recio-Blanco, A.; Reylé, C.; Riello, M.; Rimoldini, L.; Roegiers,
T.; Rybizki, J.; Sarro, L. M.; Smith, M.; Utrilla, E.; van Leeuwen,
M.; Abbas, U.; Ábrahám, P.; Abreu Aramburu, A.; Aerts, C.; Aguado,
J. J.; Ajaj, M.; Aldea-Montero, F.; Altavilla, G.; Álvarez, M. A.;
Alves, J.; Anders, F.; Anderson, R. I.; Anglada Varela, E.; Antoja, T.;
Baines, D.; Baker, S. G.; Balaguer-Núñez, L.; Balbinot, E.; Balog,
Z.; Barache, C.; Barbato, D.; Barros, M.; Bartolomé, S.; Bassilana,
J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.; Bernet, M.;
Bertone, S.; Bianchi, L.; Binnenfeld, A.; Blanco-Cuaresma, S.; Blazere,
A.; Boch, T.; Bombrun, A.; Bossini, D.; Bouquillon, S.; Bragaglia, A.;
Bramante, L.; Breedt, E.; Bressan, A.; Brouillet, N.; Brugaletta, E.;
Bucciarelli, B.; Burlacu, A.; Butkevich, A. G.; Buzzi, R.; Caffau,
E.; Cancelliere, R.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.;
Carnerero, M. I.; Carrasco, J. M.; Casamiquela, L.; Castellani, M.;
Castro-Ginard, A.; Chaoul, L.; Charlot, P.; Chemin, L.; Chiaramida,
V.; Chiavassa, A.; Chornay, N.; Comoretto, G.; Contursi, G.; Cooper,
W. J.; Cornez, T.; Cowell, S.; Crifo, F.; Cropper, M.; Crosta, M.;
Crowley, C.; Dafonte, C.; Dapergolas, A.; David, P.; de Laverny, P.;
De Luise, F.; De March, R.; De Ridder, J.; de Souza, R.; de Torres,
A.; del Peloso, E. F.; del Pozo, E.; Delbo, M.; Delgado, A.; Delisle,
J. -B.; Demouchy, C.; Dharmawardena, T. E.; Diakite, S.; Diener,
C.; Distefano, E.; Dolding, C.; Enke, H.; Fabre, C.; Fabrizio, M.;
Fedorets, G.; Fernique, P.; Figueras, F.; Fournier, Y.; Fouron, C.;
Fragkoudi, F.; Gai, M.; Garcia-Gutierrez, A.; Garcia-Reinaldos, M.;
García-Torres, M.; Garofalo, A.; Gavel, A.; Gerlach, E.; Geyer,
R.; Gilmore, G.; Girona, S.; Giuffrida, G.; Gomel, R.; Gomez, A.;
González-Núñez, J.; González-Santamaría, I.; González-Vidal,
J. J.; Granvik, M.; Guillout, P.; Guiraud, J.; Gutiérrez-Sánchez, R.;
Guy, L. P.; Hatzidimitriou, D.; Hauser, M.; Haywood, M.; Helmer, A.;
Helmi, A.; Sarmiento, M. H.; Hidalgo, S. L.; Hładczuk, N.; Hobbs, D.;
Holland, G.; Huckle, H. E.; Jardine, K.; Jasniewicz, G.; Jean-Antoine
Piccolo, A.; Jiménez-Arranz, Ó.; Juaristi Campillo, J.; Julbe, F.;
Karbevska, L.; Khanna, S.; Kordopatis, G.; Korn, A. J.; Kóspál,
Á; Kostrzewa-Rutkowska, Z.; Kruszyńska, K.; Kun, M.; Laizeau, P.;
Lambert, S.; Lanza, A. F.; Lasne, Y.; Le Campion, J. -F.; Lebreton, Y.;
Lebzelter, T.; Leccia, S.; Lecoeur-Taibi, I.; Liao, S.; Licata, E. L.;
Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; Lorca,
A.; Loup, C.; Madrero Pardo, P.; Magdaleno Romeo, A.; Managau, S.;
Mann, R. G.; Manteiga, M.; Marchant, J. M.; Marconi, M.; Marcos, J.;
Marcos Santos, M. M. S.; Marín Pina, D.; Marinoni, S.; Marocco, F.;
Marshall, D. J.; Polo, L. Martin; Martín-Fleitas, J. M.; Marton, G.;
Mary, N.; Masip, A.; Massari, D.; Mastrobuono-Battisti, A.; McMillan,
P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Mints, A.; Molina, D.;
Molinaro, R.; Molnár, L.; Monari, G.; Monguió, M.; Montegriffo, P.;
Montero, A.; Mor, R.; Mora, A.; Morbidelli, R.; Morris, D.; Muraveva,
T.; Murphy, C. P.; Musella, I.; Nagy, Z.; Noval, L.; Ocaña, F.; Ogden,
A.; Ordenovic, C.; Osinde, J. O.; Pagani, C.; Pagano, I.; Palaversa,
L.; Palicio, P. A.; Pallas-Quintela, L.; Panahi, A.; Payne-Wardenaar,
S.; Peñalosa Esteller, X.; Penttilä, A.; Pichon, B.; Piersimoni,
A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Prša, A.;
Pulone, L.; Racero, E.; Ragaini, S.; Rainer, M.; Raiteri, C. M.; Ramos,
P.; Ramos-Lerate, M.; Regibo, S.; Richards, P. J.; Rios Diaz, C.;
Ripepi, V.; Riva, A.; Rix, H. -W.; Rixon, G.; Robichon, N.; Robin,
A. C.; Robin, C.; Roelens, M.; Rogues, H. R. O.; Rohrbasser, L.;
Romero-Gómez, M.; Rowell, N.; Royer, F.; Ruz Mieres, D.; Rybicki,
K. A.; Sáez Núñez, A.; Sagristà Sellés, A.; Salguero, E.; Samaras,
N.; Sanchez Gimenez, V.; Sanna, N.; Santoveña, R.; Sarasso, M.;
Schultheis, M. S.; Sciacca, E.; Segol, M.; Segovia, J. C.; Semeux,
D.; Siddiqui, H. I.; Siebert, A.; Siltala, L.; Silvelo, A.; Slezak,
E.; Slezak, I.; Smart, R. L.; Snaith, O. N.; Solano, E.; Solitro,
F.; Souami, D.; Souchay, J.; Spagna, A.; Spina, L.; Spoto, F.;
Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.; Süveges,
M.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.; Taris, F.; Taylor,
M. B.; Teixeira, R.; Tolomei, L.; Tonello, N.; Torra, F.; Torra, J.;
Torralba Elipe, G.; Trabucchi, M.; Tsounis, A. T.; Turon, C.; Ulla,
A.; Unger, N.; Vaillant, M. V.; van Dillen, E.; van Reeven, W.; Vanel,
O.; Vecchiato, A.; Viala, Y.; Vicente, D.; Voutsinas, S.; Weiler,
M.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Yvard, P.; Zhao, H.;
Zorec, J.; Zucker, S.
2022arXiv220605595G Altcode:
The Gaia DR3 Catalogue contains for the first time about eight
hundred thousand solutions with either orbital elements or trend
parameters for astrometric, spectroscopic and eclipsing binaries, and
combinations of them. This paper aims to illustrate the huge potential
of this large non-single star catalogue. Using the orbital solutions
together with models of the binaries, a catalogue of tens of thousands
of stellar masses, or lower limits, partly together with consistent
flux ratios, has been built. Properties concerning the completeness
of the binary catalogues are discussed, statistical features of the
orbital elements are explained and a comparison with other catalogues
is performed. Illustrative applications are proposed for binaries
across the H-R diagram. The binarity is studied in the RGB/AGB and a
search for genuine SB1 among long-period variables is performed. The
discovery of new EL CVn systems illustrates the potential of combining
variability and binarity catalogues. Potential compact object companions
are presented, mainly white dwarf companions or double degenerates,
but one candidate neutron star is also presented. Towards the bottom of
the main sequence, the orbits of previously-suspected binary ultracool
dwarfs are determined and new candidate binaries are discovered. The
long awaited contribution of Gaia to the analysis of the substellar
regime shows the brown dwarf desert around solar-type stars using true,
rather than minimum, masses, and provides new important constraints on
the occurrence rates of substellar companions to M dwarfs. Several
dozen new exoplanets are proposed, including two with validated
orbital solutions and one super-Jupiter orbiting a white dwarf, all
being candidates requiring confirmation. Beside binarity, higher order
multiple systems are also found.
---------------------------------------------------------
Title: Gaia Data Release 3: Chemical cartography of the Milky Way
Authors: Gaia Collaboration; Recio-Blanco, A.; Kordopatis, G.; de
Laverny, P.; Palicio, P. A.; Spagna, A.; Spina, L.; Katz, D.; Re
Fiorentin, P.; Poggio, E.; McMillan, P. J.; Vallenari, A.; Lattanzi,
M. G.; Seabroke, G. M.; Casamiquela, L.; Bragaglia, A.; Antoja,
T.; Bailer-Jones, C. A. L.; Andrae, R.; Fouesneau, M.; Cropper, M.;
Cantat-Gaudin, T.; Heiter, U.; Bijaoui, A.; Brown, A. G. A.; Prusti,
T.; de Bruijne, J. H. J.; Arenou, F.; Babusiaux, C.; Biermann, M.;
Creevey, O. L.; Ducourant, C.; Evans, D. W.; Eyer, L.; Guerra, R.;
Hutton, A.; Jordi, C.; Klioner, S. A.; Lammers, U. L.; Lindegren,
L.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.;
Sartoretti, P.; Soubiran, C.; Tanga, P.; Walton, N. A.; Bastian, U.;
Drimmel, R.; Jansen, F.; van Leeuwen, F.; Bakker, J.; Cacciari, C.;
Castañeda, J.; De Angeli, F.; Fabricius, C.; Frémat, Y.; Galluccio,
L.; Guerrier, A.; Masana, E.; Messineo, R.; Mowlavi, N.; Nicolas,
C.; Nienartowicz, K.; Pailler, F.; Panuzzo, P.; Riclet, F.; Roux, W.;
Sordo, R.; Thévenin, F.; Gracia-Abril, G.; Portell, J.; Teyssier, D.;
Altmann, M.; Audard, M.; Bellas-Velidis, I.; Benson, K.; Berthier,
J.; Blomme, R.; Burgess, P. W.; Busonero, D.; Busso, G.; Cánovas,
H.; Carry, B.; Cellino, A.; Cheek, N.; Clementini, G.; Damerdji,
Y.; Davidson, M.; de Teodoro, P.; Nuñez Campos, M.; Delchambre,
L.; Dell'Oro, A.; Esquej, P.; Fernández-Hernández, J.; Fraile, E.;
Garabato, D.; García-Lario, P.; Gosset, E.; Haigron, R.; Halbwachs,
J. -L.; Hambly, N. C.; Harrison, D. L.; Hernández, J.; Hestroffer,
D.; Hodgkin, S. T.; Holl, B.; Janßen, K.; Jevardat de Fombelle, G.;
Jordan, S.; Krone-Martins, A.; Lanzafame, A. C.; Löffler, W.; Marchal,
O.; Marrese, P. M.; Moitinho, A.; Muinonen, K.; Osborne, P.; Pancino,
E.; Pauwels, T.; Reylé, C.; Riello, M.; Rimoldini, L.; Roegiers,
T.; Rybizki, J.; Sarro, L. M.; Siopis, C.; Smith, M.; Sozzetti,
A.; Utrilla, E.; van Leeuwen, M.; Abbas, U.; Ábrahám, P.; Abreu
Aramburu, A.; Aerts, C.; Aguado, J. J.; Ajaj, M.; Aldea-Montero, F.;
Altavilla, G.; Álvarez, M. A.; Alves, J.; Anders, F.; Anderson, R. I.;
Anglada Varela, E.; Baines, D.; Baker, S. G.; Balaguer-Núñez, L.;
Balbinot, E.; Balog, Z.; Barache, C.; Barbato, D.; Barros, M.; Barstow,
M. A.; Bartolomé, S.; Bassilana, J. -L.; Bauchet, N.; Becciani, U.;
Bellazzini, M.; Berihuete, A.; Bernet, M.; Bertone, S.; Bianchi, L.;
Binnenfeld, A.; Blanco-Cuaresma, S.; Boch, T.; Bombrun, A.; Bossini,
D.; Bouquillon, S.; Bramante, L.; Breedt, E.; Bressan, A.; Brouillet,
N.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.; Butkevich, A. G.;
Buzzi, R.; Caffau, E.; Cancelliere, R.; Carballo, R.; Carlucci, T.;
Carnerero, M. I.; Carrasco, J. M.; Castellani, M.; Castro-Ginard,
A.; Chaoul, L.; Charlot, P.; Chemin, L.; Chiaramida, V.; Chiavassa,
A.; Chornay, N.; Comoretto, G.; Contursi, G.; Cooper, W. J.; Cornez,
T.; Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Dafonte, C.;
Dapergolas, A.; David, P.; De Luise, F.; De March, R.; De Ridder,
J.; de Souza, R.; de Torres, A.; del Peloso, E. F.; del Pozo, E.;
Delbo, M.; Delgado, A.; Delisle, J. -B.; Demouchy, C.; Dharmawardena,
T. E.; Di Matteo, P.; Diakite, S.; Diener, C.; Distefano, E.; Dolding,
C.; Edvardsson, B.; Enke, H.; Fabre, C.; Fabrizio, M.; Faigler, S.;
Fedorets, G.; Fernique, P.; Figueras, F.; Fournier, Y.; Fouron, C.;
Fragkoudi, F.; Gai, M.; Garcia-Gutierrez, A.; Garcia-Reinaldos, M.;
García-Torres, M.; Garofalo, A.; Gavel, A.; Gavras, P.; Gerlach,
E.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona, S.; Giuffrida, G.;
Gomel, R.; Gomez, A.; González-Núñez, J.; González-Santamaría,
I.; González-Vidal, J. J.; Granvik, M.; Guillout, P.; Guiraud, J.;
Gutiérrez-Sánchez, R.; Guy, L. P.; Hatzidimitriou, D.; Hauser,
M.; Haywood, M.; Helmer, A.; Helmi, A.; Sarmiento, M. H.; Hidalgo,
S. L.; Hładczuk, N.; Hobbs, D.; Holland, G.; Huckle, H. E.; Jardine,
K.; Jasniewicz, G.; Jean-Antoine Piccolo, A.; Jiménez-Arranz,
Ó.; Juaristi Campillo, J.; Julbe, F.; Karbevska, L.; Kervella,
P.; Khanna, S.; Korn, A. J.; Kóspál, Á; Kostrzewa-Rutkowska,
Z.; Kruszyńska, K.; Kun, M.; Laizeau, P.; Lambert, S.; Lanza,
A. F.; Lasne, Y.; Le Campion, J. -F.; Lebreton, Y.; Lebzelter, T.;
Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Liao, S.; Licata, E. L.;
Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; Lorca,
A.; Loup, C.; Madrero Pardo, P.; Magdaleno Romeo, A.; Managau, S.;
Mann, R. G.; Manteiga, M.; Marchant, J. M.; Marconi, M.; Marcos, J.;
Marcos Santos, M. M. S.; Marín Pina, D.; Marinoni, S.; Marocco, F.;
Marshall, D. J.; Polo, L. Martin; Martín-Fleitas, J. M.; Marton, G.;
Mary, N.; Masip, A.; Massari, D.; Mastrobuono-Battisti, A.; Mazeh,
T.; Messina, S.; Michalik, D.; Millar, N. R.; Mints, A.; Molina, D.;
Molinaro, R.; Molnár, L.; Monari, G.; Monguió, M.; Montegriffo, P.;
Montero, A.; Mor, R.; Mora, A.; Morbidelli, R.; Morel, T.; Morris, D.;
Muraveva, T.; Murphy, C. P.; Musella, I.; Nagy, Z.; Noval, L.; Ocaña,
F.; Ogden, A.; Ordenovic, C.; Osinde, J. O.; Pagani, C.; Pagano, I.;
Palaversa, L.; Pallas-Quintela, L.; Panahi, A.; Payne-Wardenaar, S.;
Peñalosa Esteller, X.; Penttilä, A.; Pichon, B.; Piersimoni, A. M.;
Pineau, F. -X.; Plachy, E.; Plum, G.; Prša, A.; Pulone, L.; Racero,
E.; Ragaini, S.; Rainer, M.; Raiteri, C. M.; Ramos, P.; Ramos-Lerate,
M.; Regibo, S.; Richards, P. J.; Rios Diaz, C.; Ripepi, V.; Riva,
A.; Rix, H. -W.; Rixon, G.; Robichon, N.; Robin, A. C.; Robin, C.;
Roelens, M.; Rogues, H. R. O.; Rohrbasser, L.; Romero-Gómez, M.;
Rowell, N.; Royer, F.; Ruz Mieres, D.; Rybicki, K. A.; Sadowski, G.;
Sáez Núñez, A.; Sagristà Sellés, A.; Sahlmann, J.; Salguero,
E.; Samaras, N.; Sanchez Gimenez, V.; Sanna, N.; Santoveña, R.;
Sarasso, M.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.;
Ségransan, D.; Semeux, D.; Shahaf, S.; Siddiqui, H. I.; Siebert,
A.; Siltala, L.; Silvelo, A.; Slezak, E.; Slezak, I.; Smart, R. L.;
Snaith, O. N.; Solano, E.; Solitro, F.; Souami, D.; Souchay, J.;
Spoto, F.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.;
Süveges, M.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.; Taris,
F.; Taylor, M. B.; Teixeira, R.; Tolomei, L.; Tonello, N.; Torra,
F.; Torra, J.; Torralba Elipe, G.; Trabucchi, M.; Tsounis, A. T.;
Turon, C.; Ulla, A.; Unger, N.; Vaillant, M. V.; van Dillen, E.;
van Reeven, W.; Vanel, O.; Vecchiato, A.; Viala, Y.; Vicente, D.;
Voutsinas, S.; Weiler, M.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.;
Yvard, P.; Zhao, H.; Zorec, J.; Zucker, S.; Zwitter, T.
2022arXiv220605534G Altcode:
Gaia DR3 opens a new era of all-sky spectral analysis of stellar
populations thanks to the nearly 5.6 million stars observed by the RVS
and parametrised by the GSP-spec module. The all-sky Gaia chemical
cartography allows a powerful and precise chemo-dynamical view of
the Milky Way with unprecedented spatial coverage and statistical
robustness. First, it reveals the strong vertical symmetry of the
Galaxy and the flared structure of the disc. Second, the observed
kinematic disturbances of the disc -- seen as phase space correlations
-- and kinematic or orbital substructures are associated with chemical
patterns that favour stars with enhanced metallicities and lower
[alpha/Fe] abundance ratios compared to the median values in the radial
distributions. This is detected both for young objects that trace the
spiral arms and older populations. Several alpha, iron-peak elements
and at least one heavy element trace the thin and thick disc properties
in the solar cylinder. Third, young disc stars show a recent chemical
impoverishment in several elements. Fourth, the largest chemo-dynamical
sample of open clusters analysed so far shows a steepening of the
radial metallicity gradient with age, which is also observed in the
young field population. Finally, the Gaia chemical data have the
required coverage and precision to unveil galaxy accretion debris
and heated disc stars on halo orbits through their [alpha/Fe] ratio,
and to allow the study of the chemo-dynamical properties of globular
clusters. Gaia DR3 chemo-dynamical diagnostics open new horizons before
the era of ground-based wide-field spectroscopic surveys. They unveil
a complex Milky Way that is the outcome of an eventful evolution,
shaping it to the present day (abridged).
---------------------------------------------------------
Title: The Complexity of the Cetus Stream Unveiled from the Fusion
of STREAMFINDER and StarGO
Authors: Yuan, Zhen; Malhan, Khyati; Sestito, Federico; Ibata, Rodrigo
A.; Martin, Nicolas F.; Chang, Jiang; Li, Ting S.; Caffau, Elisabetta;
Bonifacio, Piercarlo; Bellazzini, Michele; Huang, Yang; Voggel, Karina;
Longeard, Nicolas; Arentsen, Anke; Doliva-Dolinsky, Amandine; Navarro,
Julio; Famaey, Benoit; Starkenburg, Else; Aguado, David S.
2022ApJ...930..103Y Altcode: 2021arXiv211205775Y
We combine the power of two stream-searching tools, STREAMFINDER and
StarGO applied to the Gaia EDR3 data, to detect stellar debris belonging
to the Cetus stream system that forms a complex, nearly polar structure
around the Milky Way. In this work, we find the southern extensions
of the northern Cetus stream as the Palca stream and a new southern
stream, which overlap on the sky but have different distances. These
two stream wraps extend over more than ~100° on the sky (-60° <
δ < +40°). The current N-body model of the system reproduces both
as two wraps in the trailing arm. We also show that the Cetus system
is confidently associated with the Triangulum/Pisces, Willka Yaku,
and the recently discovered C-20 streams. The association with the
ATLAS-Aliqa Uma stream is much weaker. All of these stellar debris are
very metal-poor, comparable to the average metallicity of the southern
Cetus stream with [Fe/H] = -2.17 ± 0.20. The estimated stellar mass
of the Cetus progenitor is at least 10<SUP>5.6</SUP> M <SUB>⊙</SUB>,
compatible with Ursa Minor or Draco dwarf galaxies. The associated
globular cluster with similar stellar mass, NGC 5824 very possibly
was accreted in the same group infall. The multi-wrap Cetus stream
is a perfect example of a dwarf galaxy that has undergone several
periods of stripping, leaving behind debris at multiple locations
in the halo. The full characterization of such systems is crucial to
unravel the history of the assembly of the Milky Way, and importantly,
to provide nearby fossils to study ancient low-mass dwarf galaxies.
---------------------------------------------------------
Title: Sulfur abundances in the Galactic bulge and disk
Authors: Lucertini, Francesca; Monaco, Lorenzo; Caffau, Elisabetta;
Bonifacio, Piercarlo; Mucciareli, Alessio
2022joks.confE...2L Altcode:
Context. The measurement of α-element abundances provides a
powerful tool for placing constraints on the chemical evolution and
star formation history of galaxies. The majority of studies on the
α-element sulfur (S) are focused on local stars, making S behavior in
other environments an astronomical topic that is yet to be explored
in detail. <P />Aims. The investigation of S in the Galactic bulge
was recently considered for the first time. This work aims to improve
our knowledge on S behavior in this component of the Milky Way. <P
/>Methods. We present the S abundances of 74 dwarf and sub-giant
stars in the Galactic bulge, along with 21 and 30 F and G thick- and
thin-disk stars, respectively. We performed a local thermodynamic
equilibrium analysis and applied corrections for non-LTE on high
resolution and high signal-to-noise UVES spectra. S abundances were
derived from multiplets 1, 6, and 8 in the metallicity range of -2 <
[Fe/H] < 0.6, by spectrosynthesis or line equivalent widths. <P
/>Results. We confirm that the behavior of S resembles that of an
α-element within the Galactic bulge. In the [S/Fe] versus [Fe/H]
diagram, S presents a plateau at low metallicity, followed by a
decreasing of [S/Fe] with the increasing of [Fe/H], before reaching
[S/Fe] ∼ 0 at a super-solar metallicity. We found that the Galactic
bulge is S-rich with respect to both the thick- and thin-disks at -1
< [Fe/H] < 0.3, supporting a scenario of more rapid formation
and chemical evolution in the Galactic bulge than in the disk.
---------------------------------------------------------
Title: Gaia Early Data Release 3: The celestial reference frame
(Gaia-CRF3)
Authors: Gaia Collaboration; Klioner, S. A.; Lindegren, L.; Mignard,
F.; Hernández, J.; Ramos-Lerate, M.; Bastian, U.; Biermann, M.;
Bombrun, A.; de Torres, A.; Gerlach, E.; Geyer, R.; Hilger, T.; Hobbs,
D.; Lammers, U. L.; McMillan, P. J.; Steidelmüller, H.; Teyssier, D.;
Raiteri, C. M.; Bartolomé, S.; Bernet, M.; Castañeda, J.; Clotet,
M.; Davidson, M.; Fabricius, C.; Garralda Torres, N.; González-Vidal,
J. J.; Portell, J.; Rowell, N.; Torra, F.; Torra, J.; Brown, A. G. A.;
Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.; Arenou, F.; Babusiaux,
C.; Creevey, O. L.; Ducourant, C.; Evans, D. W.; Eyer, L.; Guerra, R.;
Hutton, A.; Jordi, C.; Luri, X.; Panem, C.; Pourbaix, D.; Randich, S.;
Sartoretti, P.; Soubiran, C.; Tanga, P.; Walton, N. A.; Bailer-Jones,
C. A. L.; Drimmel, R.; Jansen, F.; Katz, D.; Lattanzi, M. G.; van
Leeuwen, F.; Bakker, J.; Cacciari, C.; De Angeli, F.; Fouesneau, M.;
Frémat, Y.; Galluccio, L.; Guerrier, A.; Heiter, U.; Masana, E.;
Messineo, R.; Mowlavi, N.; Nicolas, C.; Nienartowicz, K.; Pailler,
F.; Panuzzo, P.; Riclet, F.; Roux, W.; Seabroke, G. M.; Sordo, R.;
Thévenin, F.; Gracia-Abril, G.; Altmann, M.; Andrae, R.; Audard, M.;
Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme, R.; Burgess,
P. W.; Busonero, D.; Busso, G.; Cánovas, H.; Carry, B.; Cellino, A.;
Cheek, N.; Clementini, G.; Damerdji, Y.; de Teodoro, P.; Nuñez Campos,
M.; Delchambre, L.; Dell'Oro, A.; Esquej, P.; Fernández-Hernández,
J.; Fraile, E.; Garabato, D.; García-Lario, P.; Gosset, E.; Haigron,
R.; Halbwachs, J. -L.; Hambly, N. C.; Harrison, D. L.; Hestroffer,
D.; Hodgkin, S. T.; Holl, B.; Janßen, K.; Jevardat de Fombelle,
G.; Jordan, S.; Krone-Martins, A.; Lanzafame, A. C.; Löffler, W.;
Marchal, O.; Marrese, P. M.; Moitinho, A.; Muinonen, K.; Osborne,
P.; Pancino, E.; Pauwels, T.; Recio-Blanco, A.; Reylé, C.; Riello,
M.; Rimoldini, L.; Roegiers, T.; Rybizki, J.; Sarro, L. M.; Siopis,
C.; Smith, M.; Sozzetti, A.; Utrilla, E.; van Leeuwen, M.; Abbas, U.;
Ábrahám, P.; Abreu Aramburu, A.; Aerts, C.; Aguado, J. J.; Ajaj, M.;
Aldea-Montero, F.; Altavilla, G.; Álvarez, M. A.; Alves, J.; Anderson,
R. I.; Anglada Varela, E.; Antoja, T.; Baines, D.; Baker, S. G.;
Balaguer-Núñez, L.; Balbinot, E.; Balog, Z.; Barache, C.; Barbato,
D.; Barros, M.; Barstow, M. A.; Bassilana, J. -L.; Bauchet, N.;
Becciani, U.; Bellazzini, M.; Berihuete, A.; Bertone, S.; Bianchi, L.;
Binnenfeld, A.; Blanco-Cuaresma, S.; Boch, T.; Bossini, D.; Bouquillon,
S.; Bragaglia, A.; Bramante, L.; Breedt, E.; Bressan, A.; Brouillet,
N.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.; Butkevich, A. G.;
Buzzi, R.; Caffau, E.; Cancelliere, R.; Cantat-Gaudin, T.; Carballo,
R.; Carlucci, T.; Carnerero, M. I.; Carrasco, J. M.; Casamiquela,
L.; Castellani, M.; Castro-Ginard, A.; Chaoul, L.; Charlot, P.;
Chemin, L.; Chiaramida, V.; Chiavassa, A.; Chornay, N.; Comoretto,
G.; Contursi, G.; Cooper, W. J.; Cornez, T.; Cowell, S.; Crifo, F.;
Cropper, M.; Crosta, M.; Crowley, C.; Dafonte, C.; Dapergolas, A.;
David, P.; de Laverny, P.; De Luise, F.; De March, R.; De Ridder, J.;
de Souza, R.; del Peloso, E. F.; del Pozo, E.; Delbo, M.; Delgado,
A.; Delisle, J. -B.; Demouchy, C.; Dharmawardena, T. E.; Diakite, S.;
Diener, C.; Distefano, E.; Dolding, C.; Enke, H.; Fabre, C.; Fabrizio,
M.; Faigler, S.; Fedorets, G.; Fernique, P.; Fienga, A.; Figueras, F.;
Fournier, Y.; Fouron, C.; Fragkoudi, F.; Gai, M.; Garcia-Gutierrez,
A.; Garcia-Reinaldos, M.; García-Torres, M.; Garofalo, A.; Gavel,
A.; Gavras, P.; Giacobbe, P.; Gilmore, G.; Girona, S.; Giuffrida, G.;
Gomel, R.; Gomez, A.; González-Núñez, J.; González-Santamaría,
I.; Granvik, M.; Guillout, P.; Guiraud, J.; Gutiérrez-Sánchez, R.;
Guy, L. P.; Hatzidimitriou, D.; Hauser, M.; Haywood, M.; Helmer, A.;
Helmi, A.; Sarmiento, M. H.; Hidalgo, S. L.; Hładczuk, N.; Holland,
G.; Huckle, H. E.; Jardine, K.; Jasniewicz, G.; Jean-Antoine Piccolo,
A.; Jiménez-Arranz, Ó.; Juaristi Campillo, J.; Julbe, F.; Karbevska,
L.; Kervella, P.; Khanna, S.; Kordopatis, G.; Korn, A. J.; Kóspál,
Á; Kostrzewa-Rutkowska, Z.; Kruszyńska, K.; Kun, M.; Laizeau, P.;
Lambert, S.; Lanza, A. F.; Lasne, Y.; Le Campion, J. -F.; Lebreton,
Y.; Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Liao,
S.; Licata, E. L.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.;
Lobel, A.; Lorca, A.; Loup, C.; Madrero Pardo, P.; Magdaleno Romeo,
A.; Managau, S.; Mann, R. G.; Manteiga, M.; Marchant, J. M.; Marconi,
M.; Marcos, J.; Marcos Santos, M. M. S.; Marín Pina, D.; Marinoni, S.;
Marocco, F.; Marshall, D. J.; Polo, L. Martin; Martín-Fleitas, J. M.;
Marton, G.; Mary, N.; Masip, A.; Massari, D.; Mastrobuono-Battisti, A.;
Mazeh, T.; Messina, S.; Michalik, D.; Millar, N. R.; Mints, A.; Molina,
D.; Molinaro, R.; Molnár, L.; Monari, G.; Monguió, M.; Montegriffo,
P.; Montero, A.; Mor, R.; Mora, A.; Morbidelli, R.; Morel, T.; Morris,
D.; Muraveva, T.; Murphy, C. P.; Musella, I.; Nagy, Z.; Noval, L.;
Ocaña, F.; Ogden, A.; Ordenovic, C.; Osinde, J. O.; Pagani, C.;
Pagano, I.; Palaversa, L.; Palicio, P. A.; Pallas-Quintela, L.;
Panahi, A.; Payne-Wardenaar, S.; Peñalosa Esteller, X.; Penttilä,
A.; Pichon, B.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum,
G.; Poggio, E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.;
Rainer, M.; Rambaux, N.; Ramos, P.; Re Fiorentin, P.; Regibo, S.;
Richards, P. J.; Rios Diaz, C.; Ripepi, V.; Riva, A.; Rix, H. -W.;
Rixon, G.; Robichon, N.; Robin, A. C.; Robin, C.; Roelens, M.; Rogues,
H. R. O.; Rohrbasser, L.; Romero-Gómez, M.; Royer, F.; Ruz Mieres, D.;
Rybicki, K. A.; Sadowski, G.; Sáez Núñez, A.; Sagristà Sellés, A.;
Sahlmann, J.; Salguero, E.; Samaras, N.; Sanchez Gimenez, V.; Sanna,
N.; Santoveña, R.; Sarasso, M.; Schultheis, M.; Sciacca, E.; Segol,
M.; Segovia, J. C.; Ségransan, D.; Semeux, D.; Shahaf, S.; Siddiqui,
H. I.; Siebert, A.; Siltala, L.; Silvelo, A.; Slezak, E.; Slezak,
I.; Smart, R. L.; Snaith, O. N.; Solano, E.; Solitro, F.; Souami,
D.; Souchay, J.; Spagna, A.; Spina, L.; Spoto, F.; Steele,
I. A.; Stephenson, C. A.; Süveges, M.; Surdej, J.; Szabados, L.;
Szegedi-Elek, E.; Taris, F.; Taylor, M. B.; Teixeira, R.; Tolomei,
L.; Tonello, N.; Torralba Elipe, G.; Trabucchi, M.; Tsounis, A. T.;
Turon, C.; Ulla, A.; Unger, N.; Vaillant, M. V.; van Dillen, E.;
van Reeven, W.; Vanel, O.; Vecchiato, A.; Viala, Y.; Vicente, D.;
Voutsinas, S.; Weiler, M.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.;
Yvard, P.; Zhao, H.; Zorec, J.; Zucker, S.; Zwitter, T.
2022arXiv220412574G Altcode:
Gaia-CRF3 is the celestial reference frame for positions and proper
motions in the third release of data from the Gaia mission, Gaia DR3
(and for the early third release, Gaia EDR3, which contains identical
astrometric results). The reference frame is defined by the positions
and proper motions at epoch 2016.0 for a specific set of extragalactic
sources in the (E)DR3 catalogue. We describe the construction of
Gaia-CRF3, and its properties in terms of the distributions in
magnitude, colour, and astrometric quality. Compact extragalactic
sources in Gaia DR3 were identified by positional cross-matching with
17 external catalogues of quasars (QSO) and active galactic nuclei
(AGN), followed by astrometric filtering designed to remove stellar
contaminants. Selecting a clean sample was favoured over including a
higher number of extragalactic sources. For the final sample, the random
and systematic errors in the proper motions are analysed, as well as the
radio-optical offsets in position for sources in the third realisation
of the International Celestial Reference Frame (ICRF3). The Gaia-CRF3
comprises about 1.6 million QSO-like sources, of which 1.2 million have
five-parameter astrometric solutions in Gaia DR3 and 0.4 million have
six-parameter solutions. The sources span the magnitude range G = 13
to 21 with a peak density at 20.6 mag, at which the typical positional
uncertainty is about 1 mas. The proper motions show systematic errors
on the level of 12 ${\mu}$as yr${}^{-1}$ on angular scales greater than
15 deg. For the 3142 optical counterparts of ICRF3 sources in the S/X
frequency bands, the median offset from the radio positions is about
0.5 mas, but exceeds 4 mas in either coordinate for 127 sources. We
outline the future of the Gaia-CRF in the next Gaia data releases.
---------------------------------------------------------
Title: Detailed investigation of two high-speed evolved Galactic stars
Authors: Matas Pinto, Aroa del Mar; Caffau, Elisabetta; François,
Patrick; Spite, Monique; Bonifacio, Piercarlo; Wanajo, Shinya; Aoki,
Wako; Monaco, Lorenzo; Suda, Takuma; Spite, François; Sbordone,
Luca; Lombardo, Linda; Mucciarelli, Alessio
2022AN....34310032M Altcode:
The study of metal poor stars provides clarification and knowledge about
the primordial Universe. Specially, halo stars provide explanations of
the nature of the first generations of stars and the nucleosynthesis
in the metal-poor regime. We present a detailed chemical analysis and
determination of the kinematic and orbital properties of two stars
characterized by high speed with respect to the Sun. We analyzed two
high-resolution Subaru spectra employing the MyGIsFOS code, which allows
to derive the detailed chemical abundances for 28 elements (C, N, O, Na,
Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba,
La, Ce, Pr, Nd, Sm, and Eu), and abundance from two ionization states
in the case of four elements (Ti, Cr, Fe, and Zr). TYC 622-742-1 and
TYC 1193-1918-1 are metal-poor stars ([Fe/H] of −2.37 and −1.60),
they are similar in the chemical pattern with respect to Fe, they are α
enhanced and show a slight excess in Eu abundance. Both giant stars are
poor in C and rich in N, as expected for evolved stars, and this fact
is supported by the low <SUP>12</SUP>C/<SUP>13</SUP>C isotopic ratio
in TYC 1193-1918-1. Nevertheless, the C abundance of TYC 622-742-1 is
particularly low. TYC 622-742-1 and TYC 1193-1918-1 have a similar
chemical composition to the other Galactic halo stars of comparable
metallicity. According to their kinematics, both stars belong to the
Galactic halo, but they are not a part of the Gaia-Sausage-Enceladus
structure.
---------------------------------------------------------
Title: Sulfur abundances in the Galactic bulge and disk
Authors: Lucertini, F.; Monaco, L.; Caffau, E.; Bonifacio, P.;
Mucciarelli, A.
2022A&A...657A..29L Altcode: 2021arXiv210906216L
Context. The measurement of α-element abundances provides a
powerful tool for placing constraints on the chemical evolution and
star formation history of galaxies. The majority of studies on the
α-element sulfur (S) are focused on local stars, making S behavior in
other environments an astronomical topic that is yet to be explored
in detail. <BR /> Aims: The investigation of S in the Galactic bulge
was recently considered for the first time. This work aims to improve
our knowledge on S behavior in this component of the Milky Way. <BR />
Methods: We present the S abundances of 74 dwarf and sub-giant stars in
the Galactic bulge, along with 21 and 30 F and G thick- and thin-disk
stars, respectively. We performed a local thermodynamic equilibrium
analysis and applied corrections for non-LTE on high resolution and
high signal-to-noise UVES spectra. S abundances were derived from
multiplets 1, 6, and 8 in the metallicity range of − 2 < [Fe/H]
< 0.6, by spectrosynthesis or line equivalent widths. <BR /> Results:
We confirm that the behavior of S resembles that of an α-element
within the Galactic bulge. In the [S/Fe] versus [Fe/H] diagram,
S presents a plateau at low metallicity, followed by a decreasing
of [S/Fe] with the increasing of [Fe/H], before reaching [S/Fe] ~
0 at a super-solar metallicity. We found that the Galactic bulge is
S-rich with respect to both the thick- and thin-disks at − 1 <
[Fe/H] < 0.3, supporting a scenario of more rapid formation and
chemical evolution in the Galactic bulge than in the disk. <P />This
paper is based on data collected with the Very Large Telescope (VLT)
at the European Southern Observatory (ESO) on Paranal, Chile (ESO
Program ID 065.L-0507, 071.B-0529, 076.B-0055, 076.B-0133, 077.B-0507,
079.D-0567, 082.B-0453, 083.B-0265, 084.B-0837, 084.D-0965, 085.B-0399,
086.B-0757, 087.B-0600, 087.D-0724, 088.B-0349, 089.B-0047, 090.B-0204,
091.B-0289, 092.B-0626, 093.B-0700, 094.B-0282, 165.L-0263, 167.D-0173,
266.D-5655; and data from the UVES Paranal Observatory Project (ESO
DDT Program ID 266.D-5655).
---------------------------------------------------------
Title: A stellar stream remnant of a globular cluster below the
metallicity floor
Authors: Martin, Nicolas F.; Venn, Kim A.; Aguado, David S.;
Starkenburg, Else; González Hernández, Jonay I.; Ibata, Rodrigo A.;
Bonifacio, Piercarlo; Caffau, Elisabetta; Sestito, Federico; Arentsen,
Anke; Allende Prieto, Carlos; Carlberg, Raymond G.; Fabbro, Sébastien;
Fouesneau, Morgan; Hill, Vanessa; Jablonka, Pascale; Kordopatis,
Georges; Lardo, Carmela; Malhan, Khyati; Mashonkina, Lyudmila I.;
McConnachie, Alan W.; Navarro, Julio F.; Sánchez-Janssen, Rubén;
Thomas, Guillaume F.; Yuan, Zhen; Mucciarelli, Alessio
2022Natur.601...45M Altcode: 2022arXiv220101309M
Stellar ejecta gradually enrich the gas out of which subsequent stars
form, making the least chemically enriched stellar systems direct
fossils of structures formed in the early Universe<SUP>1</SUP>. Although
a few hundred stars with metal content below 1,000th of the
solar iron content are known in the Galaxy<SUP>2-4</SUP>, none of
them inhabit globular clusters, some of the oldest known stellar
structures. These show metal content of at least approximately 0.2%
of the solar metallicity ([Fe /H ]≳−2.7 )?. This metallicity
floor appears universal<SUP>5,6</SUP>, and it has been proposed that
protogalaxies that merged into the galaxies we observe today were
simply not massive enough to form clusters that survived to the present
day<SUP>7</SUP>. Here we report observations of a stellar stream, C-19,
whose metallicity is less than 0.05% of the solar metallicity ([F e /
H ]=−3.38 ±0.06 (s t a t i s t i c a l )±0.20 (s y s t e m a t i
c ))?. The low metallicity dispersion and the chemical abundances of
the C-19 stars show that this stream is the tidal remnant of the most
metal-poor globular cluster ever discovered, and is significantly below
the purported metallicity floor: clusters with significantly lower
metallicities than observed today existed in the past and contributed
their stars to the Milky Way halo.
---------------------------------------------------------
Title: The Pristine survey - XIV. Chemical analysis of two
ultra-metal-poor stars
Authors: Lardo, C.; Mashonkina, L.; Jablonka, P.; Bonifacio, P.;
Caffau, E.; Aguado, D. S.; González Hernández, J. I.; Sestito,
F.; Kielty, C. L.; Venn, K. A.; Hill, V.; Starkenburg, E.; Martin,
N. F.; Sitnova, T.; Arentsen, A.; Carlberg, R. G.; Navarro, J. F.;
Kordopatis, G.
2021MNRAS.508.3068L Altcode: 2021arXiv210914477L; 2021MNRAS.tmp.2603L
Elemental abundances of the most metal-poor stars reflect the
conditions in the early Galaxy and the properties of the first
stars. We present a spectroscopic follow-up of two ultra-metal-poor
stars ([Fe/H] < -4.0) identified by the survey Pristine: Pristine
221.8781+9.7844 and Pristine 237.8588+12.5660 (hereafter Pr 221 and Pr
237, respectively). Combining data with earlier observations, we find a
radial velocity of -149.25 ± 0.27 and -3.18 ± 0.19 km s<SUP>-1</SUP>
for Pr 221 and Pr 237, respectively, with no evidence of variability
between 2018 and 2020. From a one-dimensional (1D) local thermodynamic
equilibrium (LTE) analysis, we measure [Fe/H]<SUB>LTE</SUB> = -4.79
± 0.14 for Pr 221 and -4.22 ± 0.12 for Pr 237, in good agreement
with previous studies. Abundances of Li, Na, Mg, Al, Si, Ca, Ti,
Fe, and Sr were derived based on the non-LTE (NLTE) line formation
calculations. When NLTE effects are included, we measure slightly
higher metallicities: [Fe/H]<SUB>NLTE</SUB> = -4.40 ± 0.13 and -3.93
± 0.12, for Pr 221 and Pr 237, respectively. Analysis of the G band
yields [C/Fe]<SUB>1D-LTE</SUB> ≤ +2.3 and [C/Fe]<SUB>1D-LTE</SUB>
≤ +2.0 for Pr 221 and Pr 237. Both stars belong to the low-carbon
band. Upper limits on nitrogen abundances are also derived. Abundances
for other elements exhibit good agreement with those of stars with
similar parameters. Finally, to get insight into the properties of
their progenitors, we compare NLTE abundances to theoretical yields
of zero-metallicity supernovae (SNe). This suggests that the SNe
progenitors had masses ranging from 10.6 to 14.4 M<SUB>⊙</SUB>
and low-energy explosions with (0.3-1.2) × 10<SUP>51</SUP> erg.
---------------------------------------------------------
Title: Young giants of intermediate mass. Evidence of rotation
and mixing
Authors: Lombardo, Linda; François, Patrick; Bonifacio, Piercarlo;
Caffau, Elisabetta; del Mar Matas Pinto, Aroa; Charbonnel, Corinne;
Meynet, Georges; Monaco, Lorenzo; Cescutti, Gabriele; Mucciarelli,
Alessio
2021A&A...656A.155L Altcode: 2021arXiv211005229L
Context. In the search of a sample of metal-poor bright giants
using Strömgren photometry, we serendipitously found a sample
of 26 young (ages younger than 1 Gyr) metal-rich giants, some of
which have high rotational velocities. <BR /> Aims: We determined
the chemical composition and rotational velocities of these stars
in order to compare them with predictions from stellar evolution
models. These stars where of spectral type A to B when on the main
sequence, and we therefore wished to compare their abundance pattern
to that of main-sequence A and B stars. <BR /> Methods: Stellar
masses were derived by comparison of the position of the stars in the
colour-magnitude diagram with theoretical evolutionary tracks. These
masses, together with Gaia photometry and parallaxes, were used to
derive the stellar parameters. We used spectrum synthesis and model
atmospheres to determine chemical abundances for 16 elements (C, N, O,
Mg, Al, Ca, Fe, Sr, Y, Ba, La, Ce, Pr, Nd, Sm, and Eu) and rotational
velocities. <BR /> Results: The age-metallicity degeneracy can affect
photometric metallicity calibrations. We identify 15 stars as likely
binary stars. All stars are in prograde motion around the Galactic
centre and belong to the thin-disc population. All but one of the sample
stars present low [C/Fe] and high [N/Fe] ratios together with constant
[(C+N+O)/Fe], suggesting that they have undergone CNO processing
and first dredge-up. The observed rotational velocities are in line
with theoretical predictions of the evolution of rotating stars. <P
/>Based on observations obtained at Observatoire de Haute Provence,
Canada-France-Hawaii Telescope and Telescopio Nazionale Galileo.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Updated radial velocities from
Gaia DR2 (Seabroke+, 2021)
Authors: Seabroke, G. M.; Fabricius, C.; Teyssier, D.; Sartoretti, P.;
Katz, D.; Cropper, M.; Antoja, T.; Benson, K.; Smith, M.; Dolding,
C.; Gosset, E.; Panuzzo, P.; Thevenin, F.; Allende Prieto, C.;
Blomme, R.; Guerrier, A.; Huckle, H.; Jean-Antoine, A.; Haigron, R.;
Marchal, O.; Baker, S.; Damerdji, Y.; David, M.; Fremat, Y.; Janssen,
K.; Jasniewicz, G.; Lobel, A.; Samaras, N.; Plum, G.; Soubiran, C.;
Vanel, O.; Zwitter, T.; Ajaj, M.; Caffau, E.; Chemin, L.; Royer, F.;
Brouillet, N.; Crifo, F.; Guy, L. P.; Hambly, N. C.; Leclerc, N.;
Mastrobuono-Battisti, A.; Viala, Y.
2021yCat..36530160S Altcode:
EDR3 status of high-velocity stars in the negative and positive tail
of DR2's radial velocity distribution. <P />(2 data files).
---------------------------------------------------------
Title: The metal-poor end of the Spite plateau. II. Chemical and
dynamical investigation
Authors: Matas Pinto, A. M.; Spite, M.; Caffau, E.; Bonifacio, P.;
Sbordone, L.; Sivarani, T.; Steffen, M.; Spite, F.; François, P.;
Di Matteo, P.
2021A&A...654A.170M Altcode: 2021arXiv211000243M
Context. The study of old, metal-poor stars deepens our knowledge on
the early stages of the universe. In particular, the study of these
stars gives us a valuable insight into the masses of the first massive
stars and their emission of ionising photons. <BR /> Aims: We present
a detailed chemical analysis and determination of the kinematic and
orbital properties of a sample of 11 dwarf stars. These are metal-poor
stars, and a few of them present a low lithium content. We inspected
whether the other elements also present anomalies. <BR /> Methods:
We analysed the high-resolution UVES spectra of a few metal-poor stars
using the Turbospectrum code to synthesise spectral lines profiles. This
allowed us to derive a detailed chemical analysis of Fe, C, Li, Na,
Mg, Al, Si, CaI, CaII, ScII, TiII, Cr, Mn, Co, Ni, Sr, and Ba. <BR />
Results: We find excellent coherence with the reference metal-poor First
Stars sample. The lithium-poor stars do not present any anomaly of the
abundance of the elements other than lithium. Among the Li-poor stars,
we show that CS 22882-027 is very probably a blue-straggler. The star
CS 30302-145, which has a Li abundance compatible with the plateau,
has a very low Si abundance and a high Mn abundance. In many aspects,
it is similar to the α-poor star HE 1424-0241, but it is less
extreme. It could have been formed in a satellite galaxy and later
been accreted by our Galaxy. This hypothesis is also supported by
its kinematics. <P />The table with equivalent widths discussed in
this paper is only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr/">cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/654/A170">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/654/A170</A>
<P />Based on observations collected at the European Organisation for
Astronomical Research in the Southern Hemisphere (Programmes 076.A-0463
PI(Lopez), 077.D-0299 PI(Bonifacio)), 086.D-0871(A) (PI Meléndez).
---------------------------------------------------------
Title: Gaia Early Data Release 3. Updated radial velocities from
Gaia DR2
Authors: Seabroke, G. M.; Fabricius, C.; Teyssier, D.; Sartoretti, P.;
Katz, D.; Cropper, M.; Antoja, T.; Benson, K.; Smith, M.; Dolding,
C.; Gosset, E.; Panuzzo, P.; Thévenin, F.; Allende Prieto, C.;
Blomme, R.; Guerrier, A.; Huckle, H.; Jean-Antoine, A.; Haigron, R.;
Marchal, O.; Baker, S.; Damerdji, Y.; David, M.; Frémat, Y.; Janßen,
K.; Jasniewicz, G.; Lobel, A.; Samaras, N.; Plum, G.; Soubiran, C.;
Vanel, O.; Zwitter, T.; Ajaj, M.; Caffau, E.; Chemin, L.; Royer, F.;
Brouillet, N.; Crifo, F.; Guy, L. P.; Hambly, N. C.; Leclerc, N.;
Mastrobuono-Battisti, A.; Viala, Y.
2021A&A...653A.160S Altcode: 2021arXiv210802796S
Context. Gaia's Early Third Data Release (EDR3) does not contain new
radial velocities because these will be published in Gaia's full third
data release (DR3), expected in the first half of 2022. To maximise
the usefulness of EDR3, Gaia's second data release (DR2) sources
(with radial velocities) are matched to EDR3 sources to allow their
DR2 radial velocities to also be included in EDR3. This presents
two considerations: (i) a list of 70 365 sources with potentially
contaminated DR2 radial velocities has been published; and (ii) EDR3
is based on a new astrometric solution and a new source list, which
means sources in DR2 may not be in EDR3. <BR /> Aims: The two aims of
this work are: (i) investigate the list in order to improve the DR2
radial velocities being included in EDR3 and to avoid false-positive
hypervelocity candidates; and (ii) match the DR2 sources (with radial
velocities) to EDR3 sources. <BR /> Methods: Thetwo methods of this
work are: (i) unpublished, preliminary DR3 radial velocities of sources
on the list, and high-velocity stars not on the list, are compared
with their DR2 radial velocities to identify and remove contaminated
DR2 radial velocities from EDR3; and (ii) proper motions and epoch
position propagation is used to attempt to match all sources with radial
velocities in DR2 to EDR3 sources. The comparison of DR2 and DR3 radial
velocities is used to resolve match ambiguities. <BR /> Results: EDR3
contains 7 209 831 sources with a DR2 radial velocity, which is 99.8%
of sources with a radial velocity in DR2 (7 224 631). 14 800 radial
velocities from DR2 are not propagated to any EDR3 sources because
(i) 3871 from the list are found to either not have a DR3 radial
velocity or it differs significantly from its DR2 value, and five
high-velocity stars not on the list are confirmed to have contaminated
radial velocities, in one case because of contamination from the
non-overlapping Radial Velocity Spectrometer windows of a nearby, bright
star; and (ii) 10 924 DR2 sources could not be satisfactorily matched to
any EDR3 sources, so their DR2 radial velocities are also missing from
EDR3. <BR /> Conclusions: The reliability of radial velocities in EDR3
has improved compared to DR2 because the update removes a small fraction
of erroneous radial velocities (0.05% of DR2 radial velocities and 5.5%
of the list). Lessons learnt from EDR3 (e.g. bright star contamination)
will improve the radial velocities in future Gaia data releases. The
main reason for radial velocities from DR2 not propagating to EDR3
is not related to DR2 radial velocity quality. It is because the DR2
astrometry is based on one component of close binary pairs, while
EDR3 astrometry is based on the other component, which prevents these
sources from being unambiguously matched.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Abundances of metal-poor stars
(Matas Pinto+, 2021)
Authors: Matas Pinto, A. M.; Spite, M.; Caffau, E.; Bonifacio, P.;
Sbordone, L.; Sivarani, T.; Steffen, M.; Spite, F.; Francois, P.;
Di Matteo, P.
2021yCat..36540170M Altcode:
The observations of the stars we studied are described in detail in
Paper I (Sbordone et al., 2010A&A...522A..26S, Cat. J/A+A/522/A26)
(see their Table 1). <P />Briefly, observations were performed with
the high-resolution spectrograph UVES at the ESO-VLT. The spectra have
a resolving power R=~40000 and were centred at 390nm (spectral range:
330-451nm) and 580nm (spectral range: 479-680nm). For two stars (BS
17572-100 and HE 1413-1954) that were previously studied in the frame
of the HERES program (Christlieb et al., 2004A&A...428.1027C;
Barklem et al., 2005A&A...439..129B, Cat. J/A+A/439/129) from
UVES spectra centred at 437nm (spectral range: 376-497nm), the blue
spectra were centred at 346 nm (spectral range: 320-386nm). The S/N of
the spectra at 400nm is only about half of the S/N measured at 670nm
(see Table 1 in Paper I) and thus generally does not exceed 50. For
two stars, CS 22188-033 and HE 0148-2611, new UVES spectra from the
ESO archives, centred at 390 and 580nm, were also used, increasing
the S/N ratio of the mean spectrum. The data were reduced using the
standard UVES pipeline with the same procedures as used in Bonifacio
et al. (2007A&A...462..851B). <P />Here we present the table with
equivalent widths discussed in the paper. <P />(2 data files).
---------------------------------------------------------
Title: The Gaia RVS benchmark stars. I. Chemical inventory of the
first sample of evolved stars and its Rb NLTE investigation
Authors: Caffau, E.; Bonifacio, P.; Korotin, S. A.; François,
P.; Lallement, R.; Matas Pinto, A. M.; Di Matteo, P.; Steffen, M.;
Mucciarelli, A.; Katz, D.; Haywood, M.; Chemin, L.; Sartoretti, P.;
Sbordone, L.; Andrievsky, S. M.; Kovtyukh, V. V.; Spite, M.; Spite,
F.; Panuzzo, P.; Royer, F.; Thévenin, F.; Ludwig, H. -G.; Marchal,
O.; Plum, G.
2021A&A...651A..20C Altcode:
Context. The Radial Velocity Spectrometer (RVS) on board the Gaia
satellite is not provided with a wavelength calibration lamp. It uses
its observations of stars with known radial velocity to derive the
dispersion relation. To derive an accurate radial velocity calibration,
a precise knowledge of the line spread function (LSF) of the RVS is
necessary. Good-quality ground-based observations in the wavelength
range of the RVS are highly desired to determine the LSF. <BR /> Aims:
Several radial velocity standard stars are available to the Gaia
community. The highest possible number of calibrators will surely
allow us to improve the accuracy of the radial velocity. Because
the LSF may vary across the focal plane of the RVS, a large number
of high-quality spectra for the LSF calibration may allow us to
better sample the properties of the focal plane. <BR /> Methods:
We selected a sample of stars to be observed with UVES at the Very
Large Telescope, in a setting including the wavelength range of RVS,
that are bright enough to allow obtaining high-quality spectra in a
short time. We also selected stars that lack chemical investigation in
order to increase the sample of bright, close by stars with a complete
chemical inventory. <BR /> Results: We here present the chemical
analysis of the first sample of 80 evolved stars. The quality of the
spectra is very good, therefore we were able to derive abundances for
20 elements. The metallicity range spanned by the sample is about 1
dex, from slightly metal-poor to solar metallicity. We derived the
Rb abundance for all stars and investigated departures from local
thermodynamical equilibrium (NLTE) in the formation of its lines. <BR />
Conclusions: The sample of spectra is of good quality, which is useful
for a Gaia radial velocity calibration. The Rb NLTE effects in this
stellar parameters range are small but sometimes non-negligible,
especially for spectra of this good quality. <P />Tables B.3
and C.1 are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/651/A20">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/651/A20</A>
<P />Based on observations made with UVES at VLT 104.D.0325.
---------------------------------------------------------
Title: TOPoS. VI. The metal-weak tail of the metallicity distribution
functions of the Milky Way and the Gaia-Sausage-Enceladus structure
Authors: Bonifacio, P.; Monaco, L.; Salvadori, S.; Caffau, E.; Spite,
M.; Sbordone, L.; Spite, F.; Ludwig, H. -G.; Di Matteo, P.; Haywood,
M.; François, P.; Koch-Hansen, A. J.; Christlieb, N.; Zaggia, S.
2021A&A...651A..79B Altcode: 2021arXiv210508360B
Context. The goal of the Turn-Off Primordial Stars survey (TOPoS)
project is to find and analyse turn-off (TO) stars of extremely low
metallicity. To select the targets for spectroscopic follow-up at high
spectral resolution, we relied on low-resolution spectra from the
Sloan Digital Sky Survey (SDSS). <BR /> Aims: In this paper, we use
the metallicity estimates we obtained from our analysis of the SDSS
spectra to construct the metallicity distribution function (MDF) of the
Milky Way, with special emphasis on its metal-weak tail. The goal is
to provide the underlying distribution out of which the TOPoS sample
was extracted. <BR /> Methods: We made use of SDSS photometry, Gaia
photometry, and distance estimates derived from the Gaia parallaxes to
derive a metallicity estimate for a large sample of over 24 million TO
stars. This sample was used to derive the metallicity bias of the sample
for which SDSS spectra are available. <BR /> Results: We determined that
the spectroscopic sample is strongly biased in favour of metal-poor
stars, as intended. A comparison with the unbiased photometric
sample allows us to correct for the selection bias. We selected a
sub-sample of stars with reliable parallaxes for which we combined
the SDSS radial velocities with Gaia proper motions and parallaxes to
compute actions and orbital parameters in the Galactic potential. This
allowed us to characterise the stars dynamically, and in particular
to select a sub-sample that belongs to the Gaia-Sausage-Enceladus
(GSE) accretion event. We are thus also able to provide the MDF of
GSE. <BR /> Conclusions: The metal-weak tail derived in our study is
very similar to that derived in the H3 survey and in the Hamburg/ESO
Survey. This allows us to average the three MDFs and provide an
error bar for each metallicity bin. Inasmuch as the GSE structure is
representative of the progenitor galaxy that collided with the Milky
Way, that galaxy appears to be strongly deficient in metal-poor
stars compared to the Milky Way, suggesting that the metal-weak
tail of the latter has been largely formed by accretion of low-mass
galaxies rather than massive galaxies, such as the GSE progenitor. <P
/>Spectroscopic and photometric metallicities derived and discussed
in this paper as well as orbital actions computed and discussed in
this paper are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr/">cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/651/A79">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/651/A79</A>
---------------------------------------------------------
Title: Charting the Galactic Acceleration Field. I. A Search for
Stellar Streams with Gaia DR2 and EDR3 with Follow-up from ESPaDOnS
and UVES
Authors: Ibata, Rodrigo; Malhan, Khyati; Martin, Nicolas; Aubert,
Dominique; Famaey, Benoit; Bianchini, Paolo; Monari, Giacomo;
Siebert, Arnaud; Thomas, Guillaume F.; Bellazzini, Michele; Bonifacio,
Piercarlo; Caffau, Elisabetta; Renaud, Florent
2021ApJ...914..123I Altcode: 2020arXiv201205245I
We present maps of the stellar streams detected in the Gaia Data Release
2 (DR2) and Early Data Release 3 (EDR3) catalogs using the STREAMFINDER
algorithm. We also report the spectroscopic follow-up of the brighter
DR2 stream members obtained with the high-resolution CFHT/ESPaDOnS
and VLT/UVES spectrographs as well as with the medium-resolution
NTT/EFOSC2 spectrograph. Two new stellar streams that do not have a
clear progenitor are detected in DR2 (named Hríd and Gunnthrá), and
seven are detected in EDR3 (named Gaia-6 to Gaia-12). Several candidate
streams are also identified. The software also finds very long tidal
tails associated with the 15 globular clusters: NGC 288, NGC 1261, NGC
1851, NGC 2298, NGC 2808, NGC 3201, M68, ωCen, NGC 5466, Palomar 5,
M5, NGC 6101, M92, NGC 6397, and NGC 7089. These stellar streams will be
used in subsequent contributions in this series to chart the properties
of the Galactic acceleration field on ~100 pc to ~100 kpc scales.
---------------------------------------------------------
Title: Gaia Early Data Release 3. Summary of the contents and survey
properties (Corrigendum)
Authors: Gaia Collaboration; Brown, A. G. A.; Vallenari, A.;
Prusti, T.; de Bruijne, J. H. J.; Babusiaux, C.; Biermann, M.;
Creevey, O. L.; Evans, D. W.; Eyer, L.; Hutton, A.; Jansen, F.;
Jordi, C.; Klioner, S. A.; Lammers, U.; Lindegren, L.; Luri, X.;
Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.; Sartoretti, P.;
Soubiran, C.; Walton, N. A.; Arenou, F.; Bailer-Jones, C. A. L.;
Bastian, U.; Cropper, M.; Drimmel, R.; Katz, D.; Lattanzi, M. G.;
van Leeuwen, F.; Bakker, J.; Cacciari, C.; Castañeda, J.; De Angeli,
F.; Ducourant, C.; Fabricius, C.; Fouesneau, M.; Frémat, Y.; Guerra,
R.; Guerrier, A.; Guiraud, J.; Jean-Antoine Piccolo, A.; Masana, E.;
Messineo, R.; Mowlavi, N.; Nicolas, C.; Nienartowicz, K.; Pailler,
F.; Panuzzo, P.; Riclet, F.; Roux, W.; Seabroke, G. M.; Sordo, R.;
Tanga, P.; Thévenin, F.; Gracia-Abril, G.; Portell, J.; Teyssier,
D.; Altmann, M.; Andrae, R.; Bellas-Velidis, I.; Benson, K.; Berthier,
J.; Blomme, R.; Brugaletta, E.; Burgess, P. W.; Busso, G.; Carry, B.;
Cellino, A.; Cheek, N.; Clementini, G.; Damerdji, Y.; Davidson, M.;
Delchambre, L.; Dell'Oro, A.; Fernández-Hernández, J.; Galluccio,
L.; García-Lario, P.; Garcia-Reinaldos, M.; González-Núñez, J.;
Gosset, E.; Haigron, R.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
D. L.; Hatzidimitriou, D.; Heiter, U.; Hernández, J.; Hestroffer,
D.; Hodgkin, S. T.; Holl, B.; Janßen, K.; Jevardat de Fombelle, G.;
Jordan, S.; Krone-Martins, A.; Lanzafame, A. C.; Löffler, W.; Lorca,
A.; Manteiga, M.; Marchal, O.; Marrese, P. M.; Moitinho, A.; Mora, A.;
Muinonen, K.; Osborne, P.; Pancino, E.; Pauwels, T.; Petit, J. -M.;
Recio-Blanco, A.; Richards, P. J.; Riello, M.; Rimoldini, L.; Robin,
A. C.; Roegiers, T.; Rybizki, J.; Sarro, L. M.; Siopis, C.; Smith, M.;
Sozzetti, A.; Ulla, A.; Utrilla, E.; van Leeuwen, M.; van Reeven, W.;
Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.; Aguado, J. J.;
Ajaj, M.; Altavilla, G.; Álvarez, M. A.; Álvarez Cid-Fuentes, J.;
Alves, J.; Anderson, R. I.; Anglada Varela, E.; Antoja, T.; Audard, M.;
Baines, D.; Baker, S. G.; Balaguer-Núñez, L.; Balbinot, E.; Balog,
Z.; Barache, C.; Barbato, D.; Barros, M.; Barstow, M. A.; Bartolomé,
S.; Bassilana, J. -L.; Bauchet, N.; Baudesson-Stella, A.; Becciani, U.;
Bellazzini, M.; Bernet, M.; Bertone, S.; Bianchi, L.; Blanco-Cuaresma,
S.; Boch, T.; Bombrun, A.; Bossini, D.; Bouquillon, S.; Bragaglia, A.;
Bramante, L.; Breedt, E.; Bressan, A.; Brouillet, N.; Bucciarelli,
B.; Burlacu, A.; Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau,
E.; Cancelliere, R.; Cánovas, H.; Cantat-Gaudin, T.; Carballo, R.;
Carlucci, T.; Carnerero, M. I.; Carrasco, J. M.; Casamiquela, L.;
Castellani, M.; Castro-Ginard, A.; Castro Sampol, P.; Chaoul, L.;
Charlot, P.; Chemin, L.; Chiavassa, A.; Cioni, M. -R. L.; Comoretto,
G.; Cooper, W. J.; Cornez, T.; Cowell, S.; Crifo, F.; Crosta, M.;
Crowley, C.; Dafonte, C.; Dapergolas, A.; David, M.; David, P.; de
Laverny, P.; De Luise, F.; De March, R.; De Ridder, J.; de Souza,
R.; de Teodoro, P.; de Torres, A.; del Peloso, E. F.; del Pozo, E.;
Delbo, M.; Delgado, A.; Delgado, H. E.; Delisle, J. -B.; Di Matteo,
P.; Diakite, S.; Diener, C.; Distefano, E.; Dolding, C.; Eappachen,
D.; Edvardsson, B.; Enke, H.; Esquej, P.; Fabre, C.; Fabrizio, M.;
Faigler, S.; Fedorets, G.; Fernique, P.; Fienga, A.; Figueras, F.;
Fouron, C.; Fragkoudi, F.; Fraile, E.; Franke, F.; Gai, M.; Garabato,
D.; Garcia-Gutierrez, A.; García-Torres, M.; Garofalo, A.; Gavras,
P.; Gerlach, E.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona,
S.; Giuffrida, G.; Gomel, R.; Gomez, A.; Gonzalez-Santamaria, I.;
González-Vidal, J. J.; Granvik, M.; Gutiérrez-Sánchez, R.; Guy,
L. P.; Hauser, M.; Haywood, M.; Helmi, A.; Hidalgo, S. L.; Hilger,
T.; Hładczuk, N.; Hobbs, D.; Holland, G.; Huckle, H. E.; Jasniewicz,
G.; Jonker, P. G.; Juaristi Campillo, J.; Julbe, F.; Karbevska, L.;
Kervella, P.; Khanna, S.; Kochoska, A.; Kontizas, M.; Kordopatis, G.;
Korn, A. J.; Kostrzewa-Rutkowska, Z.; Kruszyńska, K.; Lambert, S.;
Lanza, A. F.; Lasne, Y.; Le Campion, J. -F.; Le Fustec, Y.; Lebreton,
Y.; Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Liao,
S.; Licata, E.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.;
Lobel, A.; Madrero Pardo, P.; Managau, S.; Mann, R. G.; Marchant,
J. M.; Marconi, M.; Marcos Santos, M. M. S.; Marinoni, S.; Marocco, F.;
Marshall, D. J.; Martin Polo, L.; Martín-Fleitas, J. M.; Masip, A.;
Massari, D.; Mastrobuono-Battisti, A.; Mazeh, T.; McMillan, P. J.;
Messina, S.; Michalik, D.; Millar, N. R.; Mints, A.; Molina, D.;
Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor, R.; Morbidelli, R.;
Morel, T.; Morris, D.; Mulone, A. F.; Munoz, D.; Muraveva, T.; Murphy,
C. P.; Musella, I.; Noval, L.; Ordénovic, C.; Orrù, G.; Osinde,
J.; Pagani, C.; Pagano, I.; Palaversa, L.; Palicio, P. A.; Panahi,
A.; Pawlak, M.; Peñalosa Esteller, X.; Penttilä, A.; Piersimoni,
A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poretti,
E.; Poujoulet, E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.;
Rainer, M.; Raiteri, C. M.; Rambaux, N.; Ramos, P.; Ramos-Lerate,
M.; Re Fiorentin, P.; Regibo, S.; Reylé, C.; Ripepi, V.; Riva, A.;
Rixon, G.; Robichon, N.; Robin, C.; Roelens, M.; Rohrbasser, L.;
Romero-Gómez, M.; Rowell, N.; Royer, F.; Rybicki, K. A.; Sadowski,
G.; Sagristà Sellés, A.; Sahlmann, J.; Salgado, J.; Salguero, E.;
Samaras, N.; Sanchez Gimenez, V.; Sanna, N.; Santoveña, R.; Sarasso,
M.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Ségransan,
D.; Semeux, D.; Shahaf, S.; Siddiqui, H. I.; Siebert, A.; Siltala,
L.; Slezak, E.; Smart, R. L.; Solano, E.; Solitro, F.; Souami, D.;
Souchay, J.; Spagna, A.; Spoto, F.; Steele, I. A.; Steidelmüller, H.;
Stephenson, C. A.; Süveges, M.; Szabados, L.; Szegedi-Elek, E.; Taris,
F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Thuillot, W.; Tonello, N.;
Torra, F.; Torra, J.; Turon, C.; Unger, N.; Vaillant, M.; van Dillen,
E.; Vanel, O.; Vecchiato, A.; Viala, Y.; Vicente, D.; Voutsinas,
S.; Weiler, M.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Yvard, P.;
Zhao, H.; Zorec, J.; Zucker, S.; Zurbach, C.; Zwitter, T.
2021A&A...650C...3G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: VizieR Online Data Catalog: TO stars metallicity estimate
(Bonifacio+, 2021)
Authors: Bonifacio, P.; Monaco, L.; Salvadori, S.; Caffau, E.; Spite,
M.; Sbordone, L.; Spite, F.; Ludwig, H. -G.; Di Matteo, P.; Haywood,
M.; Francois, P.; Koch-Hansen, A. J.; Christlieb, N. C.; Zaggia, S.
2021yCat..36510079B Altcode:
We made use of SDSS photometry, Gaia photometry, and distance estimates
derived from the Gaia parallaxes to derive a metallicity estimate for
a large sample of over 24 million TO stars. This sample was used to
derive the metallicity bias of the sample for which SDSS spectra are
available. <P />(3 data files).
---------------------------------------------------------
Title: Gaia Early Data Release 3. Structure and properties of the
Magellanic Clouds
Authors: Gaia Collaboration; Luri, X.; Chemin, L.; Clementini,
G.; Delgado, H. E.; McMillan, P. J.; Romero-Gómez, M.; Balbinot,
E.; Castro-Ginard, A.; Mor, R.; Ripepi, V.; Sarro, L. M.; Cioni,
M. -R. L.; Fabricius, C.; Garofalo, A.; Helmi, A.; Muraveva, T.;
Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.;
Babusiaux, C.; Biermann, M.; Creevey, O. L.; Evans, D. W.; Eyer,
L.; Hutton, A.; Jansen, F.; Jordi, C.; Klioner, S. A.; Lammers, U.;
Lindegren, L.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.;
Sartoretti, P.; Soubiran, C.; Walton, N. A.; Arenou, F.; Bailer-Jones,
C. A. L.; Bastian, U.; Cropper, M.; Drimmel, R.; Katz, D.; Lattanzi,
M. G.; van Leeuwen, F.; Bakker, J.; Castañeda, J.; De Angeli, F.;
Ducourant, C.; Fouesneau, M.; Frémat, Y.; Guerra, R.; Guerrier, A.;
Guiraud, J.; Jean-Antoine Piccolo, A.; Masana, E.; Messineo, R.;
Mowlavi, N.; Nicolas, C.; Nienartowicz, K.; Pailler, F.; Panuzzo,
P.; Riclet, F.; Roux, W.; Seabroke, G. M.; Sordo, R.; Tanga, P.;
Thévenin, F.; Gracia-Abril, G.; Portell, J.; Teyssier, D.; Altmann,
M.; Andrae, R.; Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme,
R.; Brugaletta, E.; Burgess, P. W.; Busso, G.; Carry, B.; Cellino,
A.; Cheek, N.; Damerdji, Y.; Davidson, M.; Delchambre, L.; Dell'Oro,
A.; Fernández-Hernández, J.; Galluccio, L.; García-Lario, P.;
Garcia-Reinaldos, M.; González-Núñez, J.; Gosset, E.; Haigron, R.;
Halbwachs, J. -L.; Hambly, N. C.; Harrison, D. L.; Hatzidimitriou,
D.; Heiter, U.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Holl,
B.; Janßen, K.; Jevardat de Fombelle, G.; Jordan, S.; Krone-Martins,
A.; Lanzafame, A. C.; Löffler, W.; Lorca, A.; Manteiga, M.; Marchal,
O.; Marrese, P. M.; Moitinho, A.; Mora, A.; Muinonen, K.; Osborne, P.;
Pancino, E.; Pauwels, T.; Recio-Blanco, A.; Richards, P. J.; Riello,
M.; Rimoldini, L.; Robin, A. C.; Roegiers, T.; Rybizki, J.; Siopis,
C.; Smith, M.; Sozzetti, A.; Ulla, A.; Utrilla, E.; van Leeuwen, M.;
van Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.;
Aguado, J. J.; Ajaj, M.; Altavilla, G.; Álvarez, M. A.; Álvarez
Cid-Fuentes, J.; Alves, J.; Anderson, R. I.; Anglada Varela, E.;
Antoja, T.; Audard, M.; Baines, D.; Baker, S. G.; Balaguer-Núñez,
L.; Balog, Z.; Barache, C.; Barbato, D.; Barros, M.; Barstow, M. A.;
Bartolomé, S.; Bassilana, J. -L.; Bauchet, N.; Baudesson-Stella, A.;
Becciani, U.; Bellazzini, M.; Bernet, M.; Bertone, S.; Bianchi, L.;
Blanco-Cuaresma, S.; Boch, T.; Bombrun, A.; Bossini, D.; Bouquillon,
S.; Bragaglia, A.; Bramante, L.; Breedt, E.; Bressan, A.; Brouillet,
N.; Bucciarelli, B.; Burlacu, A.; Busonero, D.; Butkevich, A. G.;
Buzzi, R.; Caffau, E.; Cancelliere, R.; Cánovas, H.; Cantat-Gaudin,
T.; Carballo, R.; Carlucci, T.; Carnerero, M. I.; Carrasco, J. M.;
Casamiquela, L.; Castellani, M.; Castro Sampol, P.; Chaoul, L.;
Charlot, P.; Chiavassa, A.; Comoretto, G.; Cooper, W. J.; Cornez,
T.; Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Dafonte, C.;
Dapergolas, A.; David, M.; David, P.; de Laverny, P.; De Luise, F.;
De March, R.; De Ridder, J.; de Souza, R.; de Teodoro, P.; de Torres,
A.; del Peloso, E. F.; del Pozo, E.; Delgado, A.; Delisle, J. -B.;
Di Matteo, P.; Diakite, S.; Diener, C.; Distefano, E.; Dolding,
C.; Eappachen, D.; Enke, H.; Esquej, P.; Fabre, C.; Fabrizio, M.;
Faigler, S.; Fedorets, G.; Fernique, P.; Fienga, A.; Figueras, F.;
Fouron, C.; Fragkoudi, F.; Fraile, E.; Franke, F.; Gai, M.; Garabato,
D.; Garcia-Gutierrez, A.; García-Torres, M.; Gavras, P.; Gerlach,
E.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona, S.; Giuffrida, G.;
Gomez, A.; Gonzalez-Santamaria, I.; González-Vidal, J. J.; Granvik,
M.; Gutiérrez-Sánchez, R.; Guy, L. P.; Hauser, M.; Haywood, M.;
Hidalgo, S. L.; Hilger, T.; Hładczuk, N.; Hobbs, D.; Holland, G.;
Huckle, H. E.; Jasniewicz, G.; Jonker, P. G.; Juaristi Campillo, J.;
Julbe, F.; Karbevska, L.; Kervella, P.; Khanna, S.; Kochoska, A.;
Kontizas, M.; Kordopatis, G.; Korn, A. J.; Kostrzewa-Rutkowska, Z.;
Kruszyńska, K.; Lambert, S.; Lanza, A. F.; Lasne, Y.; Le Campion,
J. -F.; Le Fustec, Y.; Lebreton, Y.; Lebzelter, T.; Leccia, S.;
Leclerc, N.; Lecoeur-Taibi, I.; Liao, S.; Licata, E.; Lindstrøm,
H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; Madrero Pardo, P.;
Managau, S.; Mann, R. G.; Marchant, J. M.; Marconi, M.; Marcos Santos,
M. M. S.; Marinoni, S.; Marocco, F.; Marshall, D. J.; Martin Polo, L.;
Martín-Fleitas, J. M.; Masip, A.; Massari, D.; Mastrobuono-Battisti,
A.; Mazeh, T.; Messina, S.; Michalik, D.; Millar, N. R.; Mints, A.;
Molina, D.; Molinaro, R.; Molnár, L.; Montegriffo, P.; Morbidelli,
R.; Morel, T.; Morris, D.; Mulone, A. F.; Munoz, D.; Murphy,
C. P.; Musella, I.; Noval, L.; Ordénovic, C.; Orrù, G.; Osinde,
J.; Pagani, C.; Pagano, I.; Palaversa, L.; Palicio, P. A.; Panahi,
A.; Pawlak, M.; Peñalosa Esteller, X.; Penttilä, A.; Piersimoni,
A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poretti,
E.; Poujoulet, E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.;
Rainer, M.; Raiteri, C. M.; Rambaux, N.; Ramos, P.; Ramos-Lerate,
M.; Re Fiorentin, P.; Regibo, S.; Reylé, C.; Riva, A.; Rixon,
G.; Robichon, N.; Robin, C.; Roelens, M.; Rohrbasser, L.; Rowell,
N.; Royer, F.; Rybicki, K. A.; Sadowski, G.; Sagristà Sellés,
A.; Sahlmann, J.; Salgado, J.; Salguero, E.; Samaras, N.; Gimenez,
V. Sanchez; Sanna, N.; Santoveña, R.; Sarasso, M.; Schultheis, M.;
Sciacca, E.; Segol, M.; Segovia, J. C.; Ségransan, D.; Semeux, D.;
Siddiqui, H. I.; Siebert, A.; Siltala, L.; Slezak, E.; Smart, R. L.;
Solano, E.; Solitro, F.; Souami, D.; Souchay, J.; Spagna, A.; Spoto,
F.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.; Süveges,
M.; Szabados, L.; Szegedi-Elek, E.; Taris, F.; Tauran, G.; Taylor,
M. B.; Teixeira, R.; Thuillot, W.; Tonello, N.; Torra, F.; Torra,
J.; Turon, C.; Unger, N.; Vaillant, M.; van Dillen, E.; Vanel, O.;
Vecchiato, A.; Viala, Y.; Vicente, D.; Voutsinas, S.; Weiler, M.;
Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Yvard, P.; Zhao, H.; Zorec,
J.; Zucker, S.; Zurbach, C.; Zwitter, T.
2021A&A...649A...7G Altcode: 2020arXiv201201771G
Context. This work is part of the Gaia Data Processing and Analysis
Consortium papers published with the Gaia Early Data Release 3
(EDR3). It is one of the demonstration papers aiming to highlight
the improvements and quality of the newly published data by applying
them to a scientific case. <BR /> Aims: We use the Gaia EDR3 data to
study the structure and kinematics of the Magellanic Clouds. The large
distance to the Clouds is a challenge for the Gaia astrometry. The
Clouds lie at the very limits of the usability of the Gaia data,
which makes the Clouds an excellent case study for evaluating the
quality and properties of the Gaia data. <BR /> Methods: The basis
of our work are two samples selected to provide a representation as
clean as possible of the stars of the Large Magellanic Cloud (LMC)
and the Small Magellanic Cloud (SMC). The selection used criteria
based on position, parallax, and proper motions to remove foreground
contamination from the Milky Way, and allowed the separation of the
stars of both Clouds. From these two samples we defined a series
of subsamples based on cuts in the colour-magnitude diagram; these
subsamples were used to select stars in a common evolutionary phase and
can also be used as approximate proxies of a selection by age. <BR />
Results: We compared the Gaia Data Release 2 and Gaia EDR3 performances
in the study of the Magellanic Clouds and show the clear improvements
in precision and accuracy in the new release. We also show that the
systematics still present in the data make the determination of the
3D geometry of the LMC a difficult endeavour; this is at the very
limit of the usefulness of the Gaia EDR3 astrometry, but it may become
feasible with the use of additional external data. We derive radial
and tangential velocity maps and global profiles for the LMC for the
several subsamples we defined. To our knowledge, this is the first
time that the two planar components of the ordered and random motions
are derived for multiple stellar evolutionary phases in a galactic disc
outside the Milky Way, showing the differences between younger and older
phases. We also analyse the spatial structure and motions in the central
region, the bar, and the disc, providing new insightsinto features and
kinematics. Finally, we show that the Gaia EDR3 data allows clearly
resolving the Magellanic Bridge, and we trace the density and velocity
flow of the stars from the SMC towards the LMC not only globally,
but also separately for young and evolved populations. This allows
us to confirm an evolved population in the Bridge that is slightly
shift from the younger population. Additionally, we were able to
study the outskirts of both Magellanic Clouds, in which we detected
some well-known features and indications of new ones. <P />Velocity
profiles are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/649/A7">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/649/A7</A>
---------------------------------------------------------
Title: Gaia Early Data Release 3. The Galactic anticentre
Authors: Gaia Collaboration; Antoja, T.; McMillan, P. J.; Kordopatis,
G.; Ramos, P.; Helmi, A.; Balbinot, E.; Cantat-Gaudin, T.; Chemin, L.;
Figueras, F.; Jordi, C.; Khanna, S.; Romero-Gómez, M.; Seabroke,
G. M.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne,
J. H. J.; Babusiaux, C.; Biermann, M.; Creevey, O. L.; Evans,
D. W.; Eyer, L.; Hutton, A.; Jansen, F.; Klioner, S. A.; Lammers,
U.; Lindegren, L.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.;
Randich, S.; Sartoretti, P.; Soubiran, C.; Walton, N. A.; Arenou, F.;
Bailer-Jones, C. A. L.; Bastian, U.; Cropper, M.; Drimmel, R.; Katz,
D.; Lattanzi, M. G.; van Leeuwen, F.; Bakker, J.; Castañeda, J.;
De Angeli, F.; Ducourant, C.; Fabricius, C.; Fouesneau, M.; Frémat,
Y.; Guerra, R.; Guerrier, A.; Guiraud, J.; Jean-Antoine Piccolo, A.;
Masana, E.; Messineo, R.; Mowlavi, N.; Nicolas, C.; Nienartowicz, K.;
Pailler, F.; Panuzzo, P.; Riclet, F.; Roux, W.; Sordo, R.; Tanga,
P.; Thévenin, F.; Gracia-Abril, G.; Portell, J.; Teyssier, D.;
Altmann, M.; Andrae, R.; Bellas-Velidis, I.; Benson, K.; Berthier,
J.; Blomme, R.; Brugaletta, E.; Burgess, P. W.; Busso, G.; Carry, B.;
Cellino, A.; Cheek, N.; Clementini, G.; Damerdji, Y.; Davidson, M.;
Delchambre, L.; Dell'Oro, A.; Fernández-Hernández, J.; Galluccio,
L.; García-Lario, P.; Garcia-Reinaldos, M.; González-Núñez, J.;
Gosset, E.; Haigron, R.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
D. L.; Hatzidimitriou, D.; Heiter, U.; Hernández, J.; Hestroffer,
D.; Hodgkin, S. T.; Holl, B.; Janßen, K.; Jevardat de Fombelle, G.;
Jordan, S.; Krone-Martins, A.; Lanzafame, A. C.; Löffler, W.; Lorca,
A.; Manteiga, M.; Marchal, O.; Marrese, P. M.; Moitinho, A.; Mora, A.;
Muinonen, K.; Osborne, P.; Pancino, E.; Pauwels, T.; Recio-Blanco, A.;
Richards, P. J.; Riello, M.; Rimoldini, L.; Robin, A. C.; Roegiers,
T.; Rybizki, J.; Sarro, L. M.; Siopis, C.; Smith, M.; Sozzetti, A.;
Ulla, A.; Utrilla, E.; van Leeuwen, M.; van Reeven, W.; Abbas, U.;
Abreu Aramburu, A.; Accart, S.; Aerts, C.; Aguado, J. J.; Ajaj, M.;
Altavilla, G.; Álvarez, M. A.; Álvarez Cid-Fuentes, J.; Alves,
J.; Anderson, R. I.; Varela, E. Anglada; Audard, M.; Baines, D.;
Baker, S. G.; Balaguer-Núñez, L.; Balog, Z.; Barache, C.; Barbato,
D.; Barros, M.; Barstow, M. A.; Bartolomé, S.; Bassilana, J. -L.;
Bauchet, N.; Baudesson-Stella, A.; Becciani, U.; Bellazzini, M.;
Bernet, M.; Bertone, S.; Bianchi, L.; Blanco-Cuaresma, S.; Boch, T.;
Bombrun, A.; Bossini, D.; Bouquillon, S.; Bragaglia, A.; Bramante, L.;
Breedt, E.; Bressan, A.; Brouillet, N.; Bucciarelli, B.; Burlacu, A.;
Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere,
R.; Cánovas, H.; Carballo, R.; Carlucci, T.; Carnerero, M. I.;
Carrasco, J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard, A.;
Castro Sampol, P.; Chaoul, L.; Charlot, P.; Chiavassa, A.; Cioni,
M. -R. L.; Comoretto, G.; Cooper, W. J.; Cornez, T.; Cowell, S.;
Crifo, F.; Crosta, M.; Crowley, C.; Dafonte, C.; Dapergolas, A.;
David, M.; David, P.; de Laverny, P.; De Luise, F.; De March, R.; De
Ridder, J.; de Souza, R.; de Teodoro, P.; de Torres, A.; del Peloso,
E. F.; del Pozo, E.; Delgado, A.; Delgado, H. E.; Delisle, J. -B.;
Di Matteo, P.; Diakite, S.; Diener, C.; Distefano, E.; Dolding, C.;
Eappachen, D.; Enke, H.; Esquej, P.; Fabre, C.; Fabrizio, M.; Faigler,
S.; Fedorets, G.; Fernique, P.; Fienga, A.; Fouron, C.; Fragkoudi, F.;
Fraile, E.; Franke, F.; Gai, M.; Garabato, D.; Garcia-Gutierrez, A.;
García-Torres, M.; Garofalo, A.; Gavras, P.; Gerlach, E.; Geyer,
R.; Giacobbe, P.; Gilmore, G.; Girona, S.; Giuffrida, G.; Gomez,
A.; Gonzalez-Santamaria, I.; González-Vidal, J. J.; Granvik, M.;
Gutiérrez-Sánchez, R.; Guy, L. P.; Hauser, M.; Haywood, M.; Hidalgo,
S. L.; Hilger, T.; Hładczuk, N.; Hobbs, D.; Holland, G.; Huckle,
H. E.; Jasniewicz, G.; Jonker, P. G.; Juaristi Campillo, J.; Julbe,
F.; Karbevska, L.; Kervella, P.; Kochoska, A.; Kontizas, M.; Korn,
A. J.; Kostrzewa-Rutkowska, Z.; Kruszyńska, K.; Lambert, S.; Lanza,
A. F.; Lasne, Y.; Le Campion, J. -F.; Le Fustec, Y.; Lebreton, Y.;
Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Liao, S.;
Licata, E.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel,
A.; Madrero Pardo, P.; Managau, S.; Mann, R. G.; Marchant, J. M.;
Marconi, M.; Marcos Santos, M. M. S.; Marinoni, S.; Marocco, F.;
Marshall, D. J.; Martin Polo, L.; Martín-Fleitas, J. M.; Masip,
A.; Massari, D.; Mastrobuono-Battisti, A.; Mazeh, T.; Messina,
S.; Michalik, D.; Millar, N. R.; Mints, A.; Molina, D.; Molinaro,
R.; Molnár, L.; Montegriffo, P.; Mor, R.; Morbidelli, R.; Morel,
T.; Morris, D.; Mulone, A. F.; Munoz, D.; Muraveva, T.; Murphy,
C. P.; Musella, I.; Noval, L.; Ordénovic, C.; Orrù, G.; Osinde,
J.; Pagani, C.; Pagano, I.; Palaversa, L.; Palicio, P. A.; Panahi,
A.; Pawlak, M.; Peñalosa Esteller, X.; Penttilä, A.; Piersimoni,
A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poretti, E.;
Poujoulet, E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.; Rainer,
M.; Raiteri, C. M.; Rambaux, N.; Ramos-Lerate, M.; Re Fiorentin, P.;
Regibo, S.; Reylé, C.; Ripepi, V.; Riva, A.; Rixon, G.; Robichon,
N.; Robin, C.; Roelens, M.; Rohrbasser, L.; Rowell, N.; Royer, F.;
Rybicki, K. A.; Sadowski, G.; Sagristà Sellés, A.; Sahlmann, J.;
Salgado, J.; Salguero, E.; Samaras, N.; Sanchez Gimenez, V.; Sanna,
N.; Santoveña, R.; Sarasso, M.; Schultheis, M.; Sciacca, E.; Segol,
M.; Segovia, J. C.; Ségransan, D.; Semeux, D.; Siddiqui, H. I.;
Siebert, A.; Siltala, L.; Slezak, E.; Smart, R. L.; Solano, E.;
Solitro, F.; Souami, D.; Souchay, J.; Spagna, A.; Spoto, F.; Steele,
I. A.; Steidelmüller, H.; Stephenson, C. A.; Süveges, M.; Szabados,
L.; Szegedi-Elek, E.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira,
R.; Thuillot, W.; Tonello, N.; Torra, F.; Torra, J.; Turon, C.; Unger,
N.; Vaillant, M.; van Dillen, E.; Vanel, O.; Vecchiato, A.; Viala,
Y.; Vicente, D.; Voutsinas, S.; Weiler, M.; Wevers, T.; Wyrzykowski,
Ł.; Yoldas, A.; Yvard, P.; Zhao, H.; Zorec, J.; Zucker, S.; Zurbach,
C.; Zwitter, T.
2021A&A...649A...8G Altcode: 2021arXiv210105811G
<BR /> Aims: We aim to demonstrate the scientific potential of the
Gaia Early Data Release 3 (EDR3) for the study of different aspects
of the Milky Way structure and evolution and we provide, at the
same time, a description of several practical aspects of the data
and examples of their usage. <BR /> Methods: We used astrometric
positions, proper motions, parallaxes, and photometry from EDR3 to
select different populations and components and to calculate the
distances and velocities in the direction of the anticentre. In this
direction, the Gaia astrometric data alone enable the calculation
of the vertical and azimuthal velocities; also, the extinction is
relatively low compared to other directions in the Galactic plane. We
then explore the disturbances of the current disc, the spatial and
kinematical distributions of early accreted versus in situ stars,
the structures in the outer parts of the disc, and the orbits of open
clusters Berkeley 29 and Saurer 1. <BR /> Results: With the improved
astrometry and photometry of EDR3, we find that: (i) the dynamics of the
Galactic disc are very complex with oscillations in the median rotation
and vertical velocities as a function of radius, vertical asymmetries,
and new correlations, including a bimodality with disc stars with large
angular momentum moving vertically upwards from below the plane, and
disc stars with slightly lower angular momentum moving preferentially
downwards; (ii) we resolve the kinematic substructure (diagonal ridges)
in the outer parts of the disc for the first time; (iii) the red
sequence that has been associated with the proto-Galactic disc that
was present at the time of the merger with Gaia-Enceladus-Sausage is
currently radially concentrated up to around 14 kpc, while the blue
sequence that has been associated with debris of the satellite extends
beyond that; (iv) there are density structures in the outer disc,
both above and below the plane, most probably related to Monoceros,
the Anticentre Stream, and TriAnd, for which the Gaia data allow an
exhaustive selection of candidate member stars and dynamical study;
and (v) the open clusters Berkeley 29 and Saurer 1, despite being
located at large distances from the Galactic centre, are on nearly
circular disc-like orbits. <BR /> Conclusions: Even with our simple
preliminary exploration of the Gaia EDR3, we demonstrate how, once
again, these data from the European Space Agency are crucial for our
understanding of the different pieces of our Galaxy and their connection
to its global structure and history. <P />Movie is available at <A
href="https://www.aanda.org/10.1051/0004-6361/202039714/olm">https://www.aanda.org</A>
---------------------------------------------------------
Title: Gaia Early Data Release 3. Acceleration of the Solar System
from Gaia astrometry
Authors: Gaia Collaboration; Klioner, S. A.; Mignard, F.; Lindegren,
L.; Bastian, U.; McMillan, P. J.; Hernández, J.; Hobbs, D.;
Ramos-Lerate, M.; Biermann, M.; Bombrun, A.; de Torres, A.; Gerlach,
E.; Geyer, R.; Hilger, T.; Lammers, U.; Steidelmüller, H.; Stephenson,
C. A.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne,
J. H. J.; Babusiaux, C.; Creevey, O. L.; Evans, D. W.; Eyer, L.;
Hutton, A.; Jansen, F.; Jordi, C.; Luri, X.; Panem, C.; Pourbaix, D.;
Randich, S.; Sartoretti, P.; Soubiran, C.; Walton, N. A.; Arenou, F.;
Bailer-Jones, C. A. L.; Cropper, M.; Drimmel, R.; Katz, D.; Lattanzi,
M. G.; van Leeuwen, F.; Bakker, J.; Castañeda, J.; De Angeli, F.;
Ducourant, C.; Fabricius, C.; Fouesneau, M.; Frémat, Y.; Guerra,
R.; Guerrier, A.; Guiraud, J.; Jean-Antoine Piccolo, A.; Masana, E.;
Messineo, R.; Mowlavi, N.; Nicolas, C.; Nienartowicz, K.; Pailler,
F.; Panuzzo, P.; Riclet, F.; Roux, W.; Seabroke, G. M.; Sordo, R.;
Tanga, P.; Thévenin, F.; Gracia-Abril, G.; Portell, J.; Teyssier,
D.; Altmann, M.; Andrae, R.; Bellas-Velidis, I.; Benson, K.; Berthier,
J.; Blomme, R.; Brugaletta, E.; Burgess, P. W.; Busso, G.; Carry, B.;
Cellino, A.; Cheek, N.; Clementini, G.; Damerdji, Y.; Davidson, M.;
Delchambre, L.; Dell'Oro, A.; Fernández-Hernández, J.; Galluccio,
L.; García-Lario, P.; Garcia-Reinaldos, M.; González-Núñez, J.;
Gosset, E.; Haigron, R.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
D. L.; Hatzidimitriou, D.; Heiter, U.; Hestroffer, D.; Hodgkin,
S. T.; Holl, B.; Janßen, K.; Jevardat de Fombelle, G.; Jordan,
S.; Krone-Martins, A.; Lanzafame, A. C.; Löffler, W.; Lorca, A.;
Manteiga, M.; Marchal, O.; Marrese, P. M.; Moitinho, A.; Mora, A.;
Muinonen, K.; Osborne, P.; Pancino, E.; Pauwels, T.; Recio-Blanco, A.;
Richards, P. J.; Riello, M.; Rimoldini, L.; Robin, A. C.; Roegiers,
T.; Rybizki, J.; Sarro, L. M.; Siopis, C.; Smith, M.; Sozzetti, A.;
Ulla, A.; Utrilla, E.; van Leeuwen, M.; van Reeven, W.; Abbas, U.;
Abreu Aramburu, A.; Accart, S.; Aerts, C.; Aguado, J. J.; Ajaj, M.;
Altavilla, G.; Álvarez, M. A.; Álvarez Cid-Fuentes, J.; Alves, J.;
Anderson, R. I.; Anglada Varela, E.; Antoja, T.; Audard, M.; Baines,
D.; Baker, S. G.; Balaguer-Núñez, L.; Balbinot, E.; Balog, Z.;
Barache, C.; Barbato, D.; Barros, M.; Barstow, M. A.; Bartolomé, S.;
Bassilana, J. -L.; Bauchet, N.; Baudesson-Stella, A.; Becciani, U.;
Bellazzini, M.; Bernet, M.; Bertone, S.; Bianchi, L.; Blanco-Cuaresma,
S.; Boch, T.; Bossini, D.; Bouquillon, S.; Bramante, L.; Breedt, E.;
Bressan, A.; Brouillet, N.; Bucciarelli, B.; Burlacu, A.; Busonero, D.;
Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere, R.; Cánovas,
H.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.; Carnerero, M. I.;
Carrasco, J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard, A.;
Castro Sampol, P.; Chaoul, L.; Charlot, P.; Chemin, L.; Chiavassa,
A.; Comoretto, G.; Cooper, W. J.; Cornez, T.; Cowell, S.; Crifo, F.;
Crosta, M.; Crowley, C.; Dafonte, C.; Dapergolas, A.; David, M.;
David, P.; de Laverny, P.; De Luise, F.; De March, R.; De Ridder,
J.; de Souza, R.; de Teodoro, P.; del Peloso, E. F.; del Pozo, E.;
Delgado, A.; Delgado, H. E.; Delisle, J. -B.; Di Matteo, P.; Diakite,
S.; Diener, C.; Distefano, E.; Dolding, C.; Eappachen, D.; Enke,
H.; Esquej, P.; Fabre, C.; Fabrizio, M.; Faigler, S.; Fedorets, G.;
Fernique, P.; Fienga, A.; Figueras, F.; Fouron, C.; Fragkoudi, F.;
Fraile, E.; Franke, F.; Gai, M.; Garabato, D.; Garcia-Gutierrez, A.;
García-Torres, M.; Garofalo, A.; Gavras, P.; Giacobbe, P.; Gilmore,
G.; Girona, S.; Giuffrida, G.; Gomez, A.; Gonzalez-Santamaria, I.;
González-Vidal, J. J.; Granvik, M.; Gutiérrez-Sánchez, R.; Guy,
L. P.; Hauser, M.; Haywood, M.; Helmi, A.; Hidalgo, S. L.; Hładczuk,
N.; Holland, G.; Huckle, H. E.; Jasniewicz, G.; Jonker, P. G.; Juaristi
Campillo, J.; Julbe, F.; Karbevska, L.; Kervella, P.; Khanna, S.;
Kochoska, A.; Kordopatis, G.; Korn, A. J.; Kostrzewa-Rutkowska, Z.;
Kruszyńska, K.; Lambert, S.; Lanza, A. F.; Lasne, Y.; Le Campion,
J. -F.; Le Fustec, Y.; Lebreton, Y.; Lebzelter, T.; Leccia, S.;
Leclerc, N.; Lecoeur-Taibi, I.; Liao, S.; Licata, E.; Lindstrøm,
H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; Madrero Pardo, P.;
Managau, S.; Mann, R. G.; Marchant, J. M.; Marconi, M.; Marcos Santos,
M. M. S.; Marinoni, S.; Marocco, F.; Marshall, D. J.; Martin Polo, L.;
Martín-Fleitas, J. M.; Masip, A.; Massari, D.; Mastrobuono-Battisti,
A.; Mazeh, T.; Messina, S.; Michalik, D.; Millar, N. R.; Mints, A.;
Molina, D.; Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor, R.;
Morbidelli, R.; Morel, T.; Morris, D.; Mulone, A. F.; Munoz, D.;
Muraveva, T.; Murphy, C. P.; Musella, I.; Noval, L.; Ordénovic, C.;
Orrù, G.; Osinde, J.; Pagani, C.; Pagano, I.; Palaversa, L.; Palicio,
P. A.; Panahi, A.; Pawlak, M.; Peñalosa Esteller, X.; Penttilä, A.;
Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.;
Poretti, E.; Poujoulet, E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini,
S.; Rainer, M.; Raiteri, C. M.; Rambaux, N.; Ramos, P.; Re Fiorentin,
P.; Regibo, S.; Reylé, C.; Ripepi, V.; Riva, A.; Rixon, G.; Robichon,
N.; Robin, C.; Roelens, M.; Rohrbasser, L.; Romero-Gómez, M.; Rowell,
N.; Royer, F.; Rybicki, K. A.; Sadowski, G.; Sagristà Sellés, A.;
Sahlmann, J.; Salgado, J.; Salguero, E.; Samaras, N.; Sanchez Gimenez,
V.; Sanna, N.; Santoveña, R.; Sarasso, M.; Schultheis, M.; Sciacca,
E.; Segol, M.; Segovia, J. C.; Ségransan, D.; Semeux, D.; Siddiqui,
H. I.; Siebert, A.; Siltala, L.; Slezak, E.; Smart, R. L.; Solano,
E.; Solitro, F.; Souami, D.; Souchay, J.; Spagna, A.; Spoto, F.;
Steele, I. A.; Süveges, M.; Szabados, L.; Szegedi-Elek, E.; Taris,
F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Thuillot, W.; Tonello, N.;
Torra, F.; Torra, J.; Turon, C.; Unger, N.; Vaillant, M.; van Dillen,
E.; Vanel, O.; Vecchiato, A.; Viala, Y.; Vicente, D.; Voutsinas, S.;
Weiler, M.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Yvard, P.; Zhao,
H.; Zorec, J.; Zucker, S.; Zurbach, C.; Zwitter, T.
2021A&A...649A...9G Altcode: 2020arXiv201202036G
Context. Gaia Early Data Release 3 (Gaia EDR3) provides accurate
astrometry for about 1.6 million compact (QSO-like) extragalactic
sources, 1.2 million of which have the best-quality five-parameter
astrometric solutions. <BR /> Aims: The proper motions of QSO-like
sources are used to reveal a systematic pattern due to the acceleration
of the solar systembarycentre with respect to the rest frame of the
Universe. Apart from being an important scientific result by itself,
the acceleration measured in this way is a good quality indicator of the
Gaia astrometric solution. <BR /> Methods: Theeffect of the acceleration
was obtained as a part of the general expansion of the vector field of
proper motions in vector spherical harmonics (VSH). Various versions
of the VSH fit and various subsets of the sources were tried and
compared to get the most consistent result and a realistic estimate of
its uncertainty. Additional tests with the Gaia astrometric solution
were used to get a better idea of the possible systematic errors in the
estimate. <BR /> Results: Our best estimate of the acceleration based on
Gaia EDR3 is (2.32 ± 0.16) × 10<SUP>−10</SUP> m s<SUP>−2</SUP> (or
7.33 ±0.51 km s<SUP>−1</SUP> Myr−1) towards α = 269.1° ± 5.4°,
δ = −31.6° ± 4.1°, corresponding to a proper motion amplitude
of 5.05 ±0.35 μas yr<SUP>−1</SUP>. This is in good agreement
with the acceleration expected from current models of the Galactic
gravitational potential. We expect that future Gaia data releases will
provide estimates of the acceleration with uncertainties substantially
below 0.1 μas yr<SUP>−1</SUP>. <P />Movie is only available at <A
href="https://www.aanda.org/10.1051/0004-6361/202039734/olm">https://www.aanda.org</A>
---------------------------------------------------------
Title: VizieR Online Data Catalog: Gaia RVS benchmark
stars. I. (Caffau+, 2021)
Authors: Caffau, E.; Bonifacio, P.; Korotin, S. A.; Francois, P.;
Lallement, R.; Matas Pinto, A. M.; Di Matteo, P.; Steffen, M.;
Mucciarelli, A.; Katz, D.; Haywood, M.; Chemin, L.; Sartoretti, P.;
Sbordone, L.; Andrievsky, S. M.; Kovtyukh, V. V.; Spite, M.; Spite,
F.; Panuzzo, P.; Royer, F.; Thevenin, F.; Ludwig, H. -G.; Marchal,
O.; Plum, G.
2021yCat..36510020C Altcode:
For this project on the UVES spectrograph, we selected the setting
437+760. The choices on the setting were that (i) the 760 range
completely covers the RVS range without any gaps, and (ii) the 437 range
is the reddest setting that can be coupled with the 760 setting. For
metal-rich stars (the majority of our targets), observations in
blue settings provide very crowded spectra, and a higher S/N can be
achieved in this selected setting than in bluer settings such as the
390 setting. <P />We chose the highest UVES resolution (slit 0.4"
in the blue arm and 0.3" in the red arm). For all observations, the
DIC2 437+760 setting was used. For the stars brighter than V magnitude
8.5, an observing block comprises ten observations of 77.5s to avoid
detector saturation. For the stars fainter than 8.5, five exposures of
202 s allow avoiding detector saturation. In this program, 90 stars
have been observed, 80 of which are evolved stars and are analysed
here. The 10 unevolved stars will be analysed with stars of similar
stellar parameters that are observed or are scheduled to be observed
for the following two ESO periods (P105 and P106). <P />(2 data files).
---------------------------------------------------------
Title: Gaia Early Data Release 3. Summary of the contents and survey
properties
Authors: Gaia Collaboration; Brown, A. G. A.; Vallenari, A.;
Prusti, T.; de Bruijne, J. H. J.; Babusiaux, C.; Biermann, M.;
Creevey, O. L.; Evans, D. W.; Eyer, L.; Hutton, A.; Jansen, F.;
Jordi, C.; Klioner, S. A.; Lammers, U.; Lindegren, L.; Luri, X.;
Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.; Sartoretti, P.;
Soubiran, C.; Walton, N. A.; Arenou, F.; Bailer-Jones, C. A. L.;
Bastian, U.; Cropper, M.; Drimmel, R.; Katz, D.; Lattanzi, M. G.;
van Leeuwen, F.; Bakker, J.; Cacciari, C.; Castañeda, J.; De Angeli,
F.; Ducourant, C.; Fabricius, C.; Fouesneau, M.; Frémat, Y.; Guerra,
R.; Guerrier, A.; Guiraud, J.; Jean-Antoine Piccolo, A.; Masana, E.;
Messineo, R.; Mowlavi, N.; Nicolas, C.; Nienartowicz, K.; Pailler,
F.; Panuzzo, P.; Riclet, F.; Roux, W.; Seabroke, G. M.; Sordo, R.;
Tanga, P.; Thévenin, F.; Gracia-Abril, G.; Portell, J.; Teyssier,
D.; Altmann, M.; Andrae, R.; Bellas-Velidis, I.; Benson, K.; Berthier,
J.; Blomme, R.; Brugaletta, E.; Burgess, P. W.; Busso, G.; Carry, B.;
Cellino, A.; Cheek, N.; Clementini, G.; Damerdji, Y.; Davidson, M.;
Delchambre, L.; Dell'Oro, A.; Fernández-Hernández, J.; Galluccio,
L.; García-Lario, P.; Garcia-Reinaldos, M.; González-Núñez, J.;
Gosset, E.; Haigron, R.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
D. L.; Hatzidimitriou, D.; Heiter, U.; Hernández, J.; Hestroffer,
D.; Hodgkin, S. T.; Holl, B.; Janßen, K.; Jevardat de Fombelle, G.;
Jordan, S.; Krone-Martins, A.; Lanzafame, A. C.; Löffler, W.; Lorca,
A.; Manteiga, M.; Marchal, O.; Marrese, P. M.; Moitinho, A.; Mora, A.;
Muinonen, K.; Osborne, P.; Pancino, E.; Pauwels, T.; Petit, J. -M.;
Recio-Blanco, A.; Richards, P. J.; Riello, M.; Rimoldini, L.; Robin,
A. C.; Roegiers, T.; Rybizki, J.; Sarro, L. M.; Siopis, C.; Smith, M.;
Sozzetti, A.; Ulla, A.; Utrilla, E.; van Leeuwen, M.; van Reeven, W.;
Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.; Aguado, J. J.;
Ajaj, M.; Altavilla, G.; Álvarez, M. A.; Álvarez Cid-Fuentes, J.;
Alves, J.; Anderson, R. I.; Anglada Varela, E.; Antoja, T.; Audard, M.;
Baines, D.; Baker, S. G.; Balaguer-Núñez, L.; Balbinot, E.; Balog,
Z.; Barache, C.; Barbato, D.; Barros, M.; Barstow, M. A.; Bartolomé,
S.; Bassilana, J. -L.; Bauchet, N.; Baudesson-Stella, A.; Becciani, U.;
Bellazzini, M.; Bernet, M.; Bertone, S.; Bianchi, L.; Blanco-Cuaresma,
S.; Boch, T.; Bombrun, A.; Bossini, D.; Bouquillon, S.; Bragaglia, A.;
Bramante, L.; Breedt, E.; Bressan, A.; Brouillet, N.; Bucciarelli,
B.; Burlacu, A.; Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau,
E.; Cancelliere, R.; Cánovas, H.; Cantat-Gaudin, T.; Carballo, R.;
Carlucci, T.; Carnerero, M. I.; Carrasco, J. M.; Casamiquela, L.;
Castellani, M.; Castro-Ginard, A.; Castro Sampol, P.; Chaoul, L.;
Charlot, P.; Chemin, L.; Chiavassa, A.; Cioni, M. -R. L.; Comoretto,
G.; Cooper, W. J.; Cornez, T.; Cowell, S.; Crifo, F.; Crosta, M.;
Crowley, C.; Dafonte, C.; Dapergolas, A.; David, M.; David, P.; de
Laverny, P.; De Luise, F.; De March, R.; De Ridder, J.; de Souza,
R.; de Teodoro, P.; de Torres, A.; del Peloso, E. F.; del Pozo, E.;
Delbo, M.; Delgado, A.; Delgado, H. E.; Delisle, J. -B.; Di Matteo,
P.; Diakite, S.; Diener, C.; Distefano, E.; Dolding, C.; Eappachen,
D.; Edvardsson, B.; Enke, H.; Esquej, P.; Fabre, C.; Fabrizio, M.;
Faigler, S.; Fedorets, G.; Fernique, P.; Fienga, A.; Figueras, F.;
Fouron, C.; Fragkoudi, F.; Fraile, E.; Franke, F.; Gai, M.; Garabato,
D.; Garcia-Gutierrez, A.; García-Torres, M.; Garofalo, A.; Gavras,
P.; Gerlach, E.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona,
S.; Giuffrida, G.; Gomel, R.; Gomez, A.; Gonzalez-Santamaria, I.;
González-Vidal, J. J.; Granvik, M.; Gutiérrez-Sánchez, R.; Guy,
L. P.; Hauser, M.; Haywood, M.; Helmi, A.; Hidalgo, S. L.; Hilger,
T.; Hładczuk, N.; Hobbs, D.; Holland, G.; Huckle, H. E.; Jasniewicz,
G.; Jonker, P. G.; Juaristi Campillo, J.; Julbe, F.; Karbevska, L.;
Kervella, P.; Khanna, S.; Kochoska, A.; Kontizas, M.; Kordopatis, G.;
Korn, A. J.; Kostrzewa-Rutkowska, Z.; Kruszyńska, K.; Lambert, S.;
Lanza, A. F.; Lasne, Y.; Le Campion, J. -F.; Le Fustec, Y.; Lebreton,
Y.; Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Liao,
S.; Licata, E.; Lindstrøm, E. P.; Lister, T. A.; Livanou, E.; Lobel,
A.; Madrero Pardo, P.; Managau, S.; Mann, R. G.; Marchant, J. M.;
Marconi, M.; Marcos Santos, M. M. S.; Marinoni, S.; Marocco, F.;
Marshall, D. J.; Martin Polo, L.; Martín-Fleitas, J. M.; Masip, A.;
Massari, D.; Mastrobuono-Battisti, A.; Mazeh, T.; McMillan, P. J.;
Messina, S.; Michalik, D.; Millar, N. R.; Mints, A.; Molina, D.;
Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor, R.; Morbidelli, R.;
Morel, T.; Morris, D.; Mulone, A. F.; Munoz, D.; Muraveva, T.; Murphy,
C. P.; Musella, I.; Noval, L.; Ordénovic, C.; Orrù, G.; Osinde,
J.; Pagani, C.; Pagano, I.; Palaversa, L.; Palicio, P. A.; Panahi,
A.; Pawlak, M.; Peñalosa Esteller, X.; Penttilä, A.; Piersimoni,
A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poretti,
E.; Poujoulet, E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.;
Rainer, M.; Raiteri, C. M.; Rambaux, N.; Ramos, P.; Ramos-Lerate,
M.; Re Fiorentin, P.; Regibo, S.; Reylé, C.; Ripepi, V.; Riva, A.;
Rixon, G.; Robichon, N.; Robin, C.; Roelens, M.; Rohrbasser, L.;
Romero-Gómez, M.; Rowell, N.; Royer, F.; Rybicki, K. A.; Sadowski,
G.; Sagristà Sellés, A.; Sahlmann, J.; Salgado, J.; Salguero, E.;
Samaras, N.; Sanchez Gimenez, V.; Sanna, N.; Santoveña, R.; Sarasso,
M.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Ségransan,
D.; Semeux, D.; Shahaf, S.; Siddiqui, H. I.; Siebert, A.; Siltala,
L.; Slezak, E.; Smart, R. L.; Solano, E.; Solitro, F.; Souami, D.;
Souchay, J.; Spagna, A.; Spoto, F.; Steele, I. A.; Steidelmüller,
H.; Stephenson, C. A.; Süveges, M.; Szabados, L.; Szegedi-Elek, E.;
Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Thuillot, W.;
Tonello, N.; Torra, F.; Torra, J.; Turon, C.; Unger, N.; Vaillant,
M.; van Dillen, E.; Vanel, O.; Vecchiato, A.; Viala, Y.; Vicente, D.;
Voutsinas, S.; Weiler, M.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.;
Yvard, P.; Zhao, H.; Zorec, J.; Zucker, S.; Zurbach, C.; Zwitter, T.
2021A&A...649A...1G Altcode: 2020arXiv201201533G
Context. We present the early installment of the third Gaia data
release, Gaia EDR3, consisting of astrometry and photometry for 1.8
billion sources brighter than magnitude 21, complemented with the
list of radial velocities from Gaia DR2. <BR /> Aims: A summary of
the contents of Gaia EDR3 is presented, accompanied by a discussion
on the differences with respect to Gaia DR2 and an overview of the
main limitations which are present in the survey. Recommendations
are made on the responsible use of Gaia EDR3 results. <BR /> Methods:
The raw data collected with the Gaia instruments during the first 34
months of the mission have been processed by the Gaia Data Processing
and Analysis Consortium and turned into this early third data release,
which represents a major advance with respect to Gaia DR2 in terms of
astrometric and photometric precision, accuracy, and homogeneity. <BR
/> Results: Gaia EDR3 contains celestial positions and the apparent
brightness in G for approximately 1.8 billion sources. For 1.5 billion
of those sources, parallaxes, proper motions, and the (G<SUB>BP</SUB>
− G<SUB>RP</SUB>) colour are also available. The passbands for
G, G<SUB>BP</SUB>, and G<SUB>RP</SUB> are provided as part of the
release. For ease of use, the 7 million radial velocities from Gaia
DR2 are included in this release, after the removal of a small number
of spurious values. New radial velocities will appear as part of Gaia
DR3. Finally, Gaia EDR3 represents an updated materialisation of the
celestial reference frame (CRF) in the optical, the Gaia-CRF3, which
is based solely on extragalactic sources. The creation of the source
list for Gaia EDR3 includes enhancements that make it more robust with
respect to high proper motion stars, and the disturbing effects of
spurious and partially resolved sources. The source list is largely the
same as that for Gaia DR2, but it does feature new sources and there
are some notable changes. The source list will not change for Gaia
DR3. <BR /> Conclusions: Gaia EDR3 represents a significant advance
over Gaia DR2, with parallax precisions increased by 30 per cent,
proper motion precisions increased by a factor of 2, and the systematic
errors in the astrometry suppressed by 30-40% for the parallaxes and
by a factor ~2.5 for the proper motions. The photometry also features
increased precision, but above all much better homogeneity across
colour, magnitude, and celestial position. A single passband for G,
G<SUB>BP</SUB>, and G<SUB>RP</SUB> is valid over the entire magnitude
and colour range, with no systematics above the 1% level
---------------------------------------------------------
Title: Gaia Early Data Release 3. The Gaia Catalogue of Nearby Stars
Authors: Gaia Collaboration; Smart, R. L.; Sarro, L. M.; Rybizki, J.;
Reylé, C.; Robin, A. C.; Hambly, N. C.; Abbas, U.; Barstow, M. A.;
de Bruijne, J. H. J.; Bucciarelli, B.; Carrasco, J. M.; Cooper, W. J.;
Hodgkin, S. T.; Masana, E.; Michalik, D.; Sahlmann, J.; Sozzetti, A.;
Brown, A. G. A.; Vallenari, A.; Prusti, T.; Babusiaux, C.; Biermann,
M.; Creevey, O. L.; Evans, D. W.; Eyer, L.; Hutton, A.; Jansen, F.;
Jordi, C.; Klioner, S. A.; Lammers, U.; Lindegren, L.; Luri, X.;
Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.; Sartoretti, P.;
Soubiran, C.; Walton, N. A.; Arenou, F.; Bailer-Jones, C. A. L.;
Bastian, U.; Cropper, M.; Drimmel, R.; Katz, D.; Lattanzi, M. G.;
van Leeuwen, F.; Bakker, J.; Castañeda, J.; De Angeli, F.; Ducourant,
C.; Fabricius, C.; Fouesneau, M.; Frémat, Y.; Guerra, R.; Guerrier,
A.; Guiraud, J.; Jean-Antoine Piccolo, A.; Messineo, R.; Mowlavi,
N.; Nicolas, C.; Nienartowicz, K.; Pailler, F.; Panuzzo, P.; Riclet,
F.; Roux, W.; Seabroke, G. M.; Sordo, R.; Tanga, P.; Thévenin, F.;
Gracia-Abril, G.; Portell, J.; Teyssier, D.; Altmann, M.; Andrae, R.;
Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme, R.; Brugaletta,
E.; Burgess, P. W.; Busso, G.; Carry, B.; Cellino, A.; Cheek, N.;
Clementini, G.; Damerdji, Y.; Davidson, M.; Delchambre, L.; Dell'Oro,
A.; Fernández-Hernández, J.; Galluccio, L.; García-Lario, P.;
Garcia-Reinaldos, M.; González-Núñez, J.; Gosset, E.; Haigron,
R.; Halbwachs, J. -L.; Harrison, D. L.; Hatzidimitriou, D.; Heiter,
U.; Hernández, J.; Hestroffer, D.; Holl, B.; Janßen, K.; Jevardat
de Fombelle, G.; Jordan, S.; Krone-Martins, A.; Lanzafame, A. C.;
Löffler, W.; Lorca, A.; Manteiga, M.; Marchal, O.; Marrese, P. M.;
Moitinho, A.; Mora, A.; Muinonen, K.; Osborne, P.; Pancino, E.;
Pauwels, T.; Recio-Blanco, A.; Richards, P. J.; Riello, M.; Rimoldini,
L.; Roegiers, T.; Siopis, C.; Smith, M.; Ulla, A.; Utrilla, E.; van
Leeuwen, M.; van Reeven, W.; Abreu Aramburu, A.; Accart, S.; Aerts,
C.; Aguado, J. J.; Ajaj, M.; Altavilla, G.; Álvarez, M. A.; Álvarez
Cid-Fuentes, J.; Alves, J.; Anderson, R. I.; Anglada Varela, E.;
Antoja, T.; Audard, M.; Baines, D.; Baker, S. G.; Balaguer-Núñez,
L.; Balbinot, E.; Balog, Z.; Barache, C.; Barbato, D.; Barros, M.;
Bartolomé, S.; Bassilana, J. -L.; Bauchet, N.; Baudesson-Stella, A.;
Becciani, U.; Bellazzini, M.; Bernet, M.; Bertone, S.; Bianchi, L.;
Blanco-Cuaresma, S.; Boch, T.; Bombrun, A.; Bossini, D.; Bouquillon,
S.; Bragaglia, A.; Bramante, L.; Breedt, E.; Bressan, A.; Brouillet,
N.; Burlacu, A.; Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau,
E.; Cancelliere, R.; Cánovas, H.; Cantat-Gaudin, T.; Carballo,
R.; Carlucci, T.; Carnerero, M. I.; Casamiquela, L.; Castellani, M.;
Castro-Ginard, A.; Castro Sampol, P.; Chaoul, L.; Charlot, P.; Chemin,
L.; Chiavassa, A.; Cioni, M. -R. L.; Comoretto, G.; Cornez, T.; Cowell,
S.; Crifo, F.; Crosta, M.; Crowley, C.; Dafonte, C.; Dapergolas, A.;
David, M.; David, P.; de Laverny, P.; De Luise, F.; De March, R.; De
Ridder, J.; de Souza, R.; de Teodoro, P.; de Torres, A.; del Peloso,
E. F.; del Pozo, E.; Delgado, A.; Delgado, H. E.; Delisle, J. -B.;
Di Matteo, P.; Diakite, S.; Diener, C.; Distefano, E.; Dolding,
C.; Eappachen, D.; Edvardsson, B.; Enke, H.; Esquej, P.; Fabre, C.;
Fabrizio, M.; Faigler, S.; Fedorets, G.; Fernique, P.; Fienga, A.;
Figueras, F.; Fouron, C.; Fragkoudi, F.; Fraile, E.; Franke, F.; Gai,
M.; Garabato, D.; Garcia-Gutierrez, A.; García-Torres, M.; Garofalo,
A.; Gavras, P.; Gerlach, E.; Geyer, R.; Giacobbe, P.; Gilmore, G.;
Girona, S.; Giuffrida, G.; Gomel, R.; Gomez, A.; Gonzalez-Santamaria,
I.; González-Vidal, J. J.; Granvik, M.; Gutiérrez-Sánchez, R.; Guy,
L. P.; Hauser, M.; Haywood, M.; Helmi, A.; Hidalgo, S. L.; Hilger,
T.; Hładczuk, N.; Hobbs, D.; Holland, G.; Huckle, H. E.; Jasniewicz,
G.; Jonker, P. G.; Juaristi Campillo, J.; Julbe, F.; Karbevska, L.;
Kervella, P.; Khanna, S.; Kochoska, A.; Kontizas, M.; Kordopatis, G.;
Korn, A. J.; Kostrzewa-Rutkowska, Z.; Kruszyńska, K.; Lambert, S.;
Lanza, A. F.; Lasne, Y.; Le Campion, J. -F.; Le Fustec, Y.; Lebreton,
Y.; Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Liao,
S.; Licata, E.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.;
Lobel, A.; Madrero Pardo, P.; Managau, S.; Mann, R. G.; Marchant,
J. M.; Marconi, M.; Marcos Santos, M. M. S.; Marinoni, S.; Marocco,
F.; Marshall, D. J.; Martin Polo, L.; Martín-Fleitas, J. M.; Masip,
A.; Massari, D.; Mastrobuono-Battisti, A.; Mazeh, T.; McMillan,
P. J.; Messina, S.; Millar, N. R.; Mints, A.; Molina, D.; Molinaro,
R.; Molnár, L.; Montegriffo, P.; Mor, R.; Morbidelli, R.; Morel,
T.; Morris, D.; Mulone, A. F.; Munoz, D.; Muraveva, T.; Murphy,
C. P.; Musella, I.; Noval, L.; Ordénovic, C.; Orrù, G.; Osinde,
J.; Pagani, C.; Pagano, I.; Palaversa, L.; Palicio, P. A.; Panahi,
A.; Pawlak, M.; Peñalosa Esteller, X.; Penttilä, A.; Piersimoni,
A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poretti,
E.; Poujoulet, E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.;
Rainer, M.; Raiteri, C. M.; Rambaux, N.; Ramos, P.; Ramos-Lerate,
M.; Re Fiorentin, P.; Regibo, S.; Ripepi, V.; Riva, A.; Rixon, G.;
Robichon, N.; Robin, C.; Roelens, M.; Rohrbasser, L.; Romero-Gómez,
M.; Rowell, N.; Royer, F.; Rybicki, K. A.; Sadowski, G.; Sagristà
Sellés, A.; Salgado, J.; Salguero, E.; Samaras, N.; Sanchez Gimenez,
V.; Sanna, N.; Santoveña, R.; Sarasso, M.; Schultheis, M.; Sciacca,
E.; Segol, M.; Segovia, J. C.; Ségransan, D.; Semeux, D.; Shahaf,
S.; Siddiqui, H. I.; Siebert, A.; Siltala, L.; Slezak, E.; Solano, E.;
Solitro, F.; Souami, D.; Souchay, J.; Spagna, A.; Spoto, F.; Steele,
I. A.; Steidelmüller, H.; Stephenson, C. A.; Süveges, M.; Szabados,
L.; Szegedi-Elek, E.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira,
R.; Thuillot, W.; Tonello, N.; Torra, F.; Torra, J.; Turon, C.; Unger,
N.; Vaillant, M.; van Dillen, E.; Vanel, O.; Vecchiato, A.; Viala, Y.;
Vicente, D.; Voutsinas, S.; Weiler, M.; Wevers, T.; Wyrzykowski, Ł.;
Yoldas, A.; Yvard, P.; Zhao, H.; Zorec, J.; Zucker, S.; Zurbach, C.;
Zwitter, T.
2021A&A...649A...6G Altcode: 2020arXiv201202061G
<BR /> Aims: We produce a clean and well-characterised catalogue of
objects within 100 pc of the Sun from the Gaia Early Data Release 3. We
characterise the catalogue through comparisons to the full data release,
external catalogues, and simulations. We carry out a first analysis
of the science that is possible with this sample to demonstrate its
potential and best practices for its use. <BR /> Methods: Theselection
of objects within 100 pc from the full catalogue used selected training
sets, machine-learning procedures, astrometric quantities, and solution
quality indicators to determine a probability that the astrometric
solution is reliable. The training set construction exploited the
astrometric data, quality flags, and external photometry. For all
candidates we calculated distance posterior probability densities
using Bayesian procedures and mock catalogues to define priors. Any
object with reliable astrometry and a non-zero probability of being
within 100 pc is included in the catalogue. <BR /> Results: We have
produced a catalogue of 331 312 objects that we estimate contains at
least 92% of stars of stellar type M9 within 100 pc of the Sun. We
estimate that 9% of the stars in this catalogue probably lie outside
100 pc, but when the distance probability function is used, a correct
treatment of this contamination is possible. We produced luminosity
functions with a high signal-to-noise ratio for the main-sequence
stars, giants, and white dwarfs. We examined in detail the Hyades
cluster, the white dwarf population, and wide-binary systems and
produced candidate lists for all three samples. We detected local
manifestations of several streams, superclusters, and halo objects,
in which we identified 12 members of Gaia Enceladus. We present the
first direct parallaxes of five objects in multiple systems within
10 pc of the Sun. <BR /> Conclusions: We provide the community
with a large, well-characterised catalogue of objects in the
solar neighbourhood. This is a primary benchmark for measuring and
understanding fundamental parameters and descriptive functions in
astronomy. <P />Tables are only available at the CDS via anonymous ftp
to <A href="http://cdsarc.u-strasbg.fr">cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/649/A6">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/649/A6</A>
---------------------------------------------------------
Title: Purveyors of fine halos. III. Chemical abundance analysis of
a potential ωCen associate
Authors: Koch-Hansen, Andreas J.; Hansen, Camilla Juul; Lombardo,
Linda; Bonifacio, Piercarlo; Hanke, Michael; Caffau, Elisabetta
2021A&A...645A..64K Altcode: 2020A&A...645A..64K; 2020arXiv201112303K
Globular clusters (GCs) are important donors to the build-up of the
Milky Way (MW) stellar halo, having contributed at the ten percent
level over the Galactic history. Stars that originated from the second
generation of dissolved or dissolving clusters can be readily identified
via distinct light-element signatures such as enhanced N and Na and
simultaneously depleted C and O abundances. In this paper we present
an extensive chemical abundance analysis of the halo star J110842,
which was previously kinematically associated with the massive MW GC
ω Centauri (ωCen), and we discuss viable scenarios from escape to
encounter. Based on a high-resolution, high signal-to-noise spectrum
of this star using the UVES spectrograph, we were able to measure 33
species of 31 elements across all nucleosynthetic channels. The star's
low metallicity of [Fe II/H] = -2.10 ± 0.02(stat.) ± 0.07(sys.) dex
places it in the lower sixth percentile of ωCen's metallicity
distribution. We find that all of the heavier-element abundances,
from α- and Fe-peak elements to neutron-capture elements are closely
compatible with ωCen's broad abundance distribution. However,
given the major overlap of this object's abundances with the bulk
of all of the MW components, this does not allow for a clear-cut
distinction of the star's origin. In contrast, our measurements
of an enhancement in CN and its position on the Na-strong locus of
the Na-O anticorrelation render it conceivable that it originally
formed as a second-generation GC star, lending support to a former
association of this halo star with the massive GC ωCen. <P />Full
Table 2 is only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr/">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/645/A64">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/645/A64</A>
<P />Based on observations obtained at ESO Paranal Observatory,
program 0104.D-0059.
---------------------------------------------------------
Title: Integration and early testing of WEAVE: the next-generation
spectroscopy facility for the William Herschel Telescope
Authors: Dalton, Gavin; Trager, Scott; Abrams, Don Carlos; Bonifacio,
Piercarlo; Aguerri, J. Alfonso L.; Vallenari, Antonella; Bishop,
Georgia; Middleton, Kevin; Benn, Chris; Dee, Kevin; Mignot, Shan;
Lewis, Ian; Pragt, Johannes; Pico, Sergio; Walton, Nicholas; Rey,
Juerg; Allende Prieto, Carlos; Lhomé, Emilie; Balcells, Marc; Terrett,
David; Brock, Matthew; Ridings, Andy; Skvarč, Jure; Verheijen, Marc;
Steele, Iain; Stuik, Remko; Kroes, Gabby; Tromp, Neils; Kragt, Jan;
Lesman, Dirk; Mottram, Chris; Bates, Stuart; Gribbin, Frank; Burgal,
Jose Alonso; Herreros, José Miguel; Delgado, José Miguel; Martin,
Carlos; Cano, Diego; Navarro, Ramon; Irwin, Mike; Peralta de Arriba,
Luis; O'Mahoney, Neil; Bianco, Andrea; Moleinezhad, Alireza; ter
Horst, Rik; Molinari, Emilio; Lodi, Marcello; Guerra, José; Baruffalo,
Andrea; Carrasco, Esperanza; Farcas, Szigfrid; Schallig, Ellen; Hughes,
Sarah; Hill, Vanessa; Smith, Dan; Drew, Janet; Poggianti, Bianca;
Iovino, Angela; Pieri, Mat; Jin, Shoko; Dominguez Palmero, Lillian;
Fariña, Cecilia; Martín, Adrian; Worley, Clare; Murphy, David;
Guest, Steve; Morris, Huw; Elswijk, Eddy; de Haan, Menno; Hanenburg,
Hiddo; Salasnich, Bernardo; Mayya, Divakara; Izazaga-Pérez, Rafael;
Gafton, Emanuel; Caffau, Elisabetta; Horville, David; Paz Chinchón,
Francisco; Falcon-Barosso, Jesus; Gänsicke, Boris; San Juan, Jose;
Hernandez, Nauzet
2020SPIE11447E..14D Altcode:
We present an update on the overall integration progress of the
WEAVE next-generation spectroscopy facility for the William Herschel
Telescope (WHT), now scheduled for first light in early-2021, with
almost all components now arrived at the observatory. We also present
a summary of the current planning behind the 5-year initial phase of
survey operations, and some detailed end-to-end science simulations
that have been implemented to evaluate the final on-sky performance
after data processing. WEAVE will provide optical ground-based follow
up of ground-based (LOFAR) and space-based (Gaia) surveys. WEAVE
is a multi-object and multi-IFU facility utilizing a new 2-degree
prime focus field of view at the WHT, with a buffered pick-and-place
positioner system hosting 1000 multi-object (MOS) fibres, 20 mini
integral field units, or a single large IFU for each observation. The
fibres are fed to a single (dual-beam) spectrograph, with total of
16k spectral pixels, located within the WHT GHRIL enclosure on the
telescope Nasmyth platform, supporting observations at R~5000 over
the full 370-1000nm wavelength range in a single exposure, or a high
resolution mode with limited coverage in each arm at R~20000.
---------------------------------------------------------
Title: Fiber links for the WEAVE instrument: the making of
Authors: Mignot, Shan; Bonifacio, Piercarlo; Fasola, Gilles; Horville,
David; Caffau, Elisabetta; Dorent, Stéphane; Croce, Sébastien; Blanc,
Sébastien; Melse, Basile-Thierry; Younès, Youssef; Reix, Florent;
Gaudemard, Julien; Dalton, Gavin; Schallig, Ellen; Lewis, Ian; Stuik,
Remko; Middleton, Kevin; Bishop, Georgia; Abrams, Don Carlos; Trager,
Scott; Aguerri, J. Alfonso; Carrasco, Esperanza; Vallenari, Antonella;
Laporte, Philippe; Barroso, Patrice; Noûs, Camille
2020SPIE11450E..2FM Altcode:
The WEAVE instrument nearing completion for the William Herschel
Telescope is a fiber-fed spectrograph operating in three different
modes. Two comprise deployable fibers at the prime focus for point-like
objects and small integral field units (IFU), the third is a large
IFU placed at the center of the field. Three distinct fiber systems
support these modes and route the photons to the spectrograph located
on the Nasmyth platform 33m away: the first features 960+940 fibers
and is duplicated to allow configuring the fibers on one plate while
observation is carried out on the other, the second has 20 hexagonal
IFUs featuring 37 fibers each, the third is a large array of 609 fibers
with twice the former's diameter. The large number of fibers and the
diversity of their instantiation have made procurement of the parts
and assembly of the custom cables a challenge. They involve project
partners in France, the UK and the Netherlands and industrial partners
in France, Canada, the USA and China to combine know-how and compress
the schedule by parallelizing assembly of the cables. Besides the
complex management that this induces, it has called for revising the
fibers' handling to relax tolerances and for a rigorous assessment
of the conformity of the products. This paper tells the story of the
making of the fiber links, presents the overall organization of the
procurement and assembly chains together with the inspection and testing
allowing for assessing the conformance of the hardware delivered.
---------------------------------------------------------
Title: Mono-enriched stars and Galactic chemical evolution. Possible
biases in observations and theory
Authors: Hansen, C. J.; Koch, A.; Mashonkina, L.; Magg, M.; Bergemann,
M.; Sitnova, T.; Gallagher, A. J.; Ilyin, I.; Caffau, E.; Zhang,
H. W.; Strassmeier, K. G.; Klessen, R. S.
2020A&A...643A..49H Altcode: 2020arXiv200911876H
A long sought after goal using chemical abundance patterns derived
from metal-poor stars is to understand the chemical evolution
of the Galaxy and to pin down the nature of the first stars (Pop
III). Metal-poor, old, unevolved stars are excellent tracers as
they preserve the abundance pattern of the gas from which they were
born, and hence they are frequently targeted in chemical tagging
studies. Here, we use a sample of 14 metal-poor stars observed with the
high-resolution spectrograph called the Potsdam Echelle Polarimetric and
Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT)
to derive abundances of 32 elements (34 including upper limits). We
present well-sampled abundance patterns for all stars obtained using
local thermodynamic equilibrium (LTE) radiative transfer codes and
one-dimensional (1D) hydrostatic model atmospheres. However, it is
currently well-known that the assumptions of 1D and LTE may hide
several issues, thereby introducing biases in our interpretation
as to the nature of the first stars and the chemical evolution of
the Galaxy. Hence, we use non-LTE (NLTE) and correct the abundances
using three-dimensional model atmospheres to present a physically
more reliable pattern. In order to infer the nature of the first
stars, we compare unevolved, cool stars, which have been enriched
by a single event ("mono-enriched"), with a set of yield predictions
to pin down the mass and energy of the Pop III progenitor. To date,
only few bona fide second generation stars that are mono-enriched
are known. A simple χ<SUP>2</SUP>-fit may bias our inferred mass
and energy just as much as the simple 1D LTE abundance pattern, and
we therefore carried out our study with an improved fitting technique
considering dilution and mixing. Our sample presents Carbon Enhanced
Metal-Poor (CEMP) stars, some of which are promising bona fide second
generation (mono-enriched) stars. The unevolved, dwarf BD+09_2190
shows a mono-enriched signature which, combined with kinematical data,
indicates that it moves in the outer halo and likely has been accreted
onto the Milky Way early on. The Pop III progenitor was likely of
25.5 M<SUB>⊙</SUB> and 0.6 foe (0.6 10<SUP>51</SUP> erg) in LTE
and 19.2 M<SUB>⊙</SUB> and 1.5 foe in NLTE, respectively. Finally,
we explore the predominant donor and formation site of the rapid
and slow neutron-capture elements. In BD-10_3742, we find an almost
clean r-process trace, as is represented in the star HD20, which is a
"metal-poor Sun benchmark" for the r-process, while TYC5481-00786-1 is
a promising CEMP-r/-s candidate that may be enriched by an asymptotic
giant branch star of an intermediate mass and metallicity. <P />The
line list is only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/643/A49">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/643/A49</A>
<P />Based on data acquired with PEPSI using the Large Binocular
Telescope (LBT). The LBT is an international collaboration among
institutions in the United States, Italy, and Germany.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Potential omega Cen associate EW
(Koch-Hansen+, 2021)
Authors: Koch-Hansen; A.; Hansen; C. J.; Lombardo; L.; Bonifacio;
P.; Hanke; M.; Caffau., E.
2020yCat..36450064K Altcode:
We performed a standard abundance analysis that employed a mixture
of equivalent width (EW) measurements, carried out via Gaussian fits
with the IRAF splot task, and spectrum synthesis. Here we employed the
same line list as in Koch & McWilliam (2014, Cat. J/A+A/565/A23,
see Table 2) with further additions in the syntheses from Biemont et
al. (2000MNRAS.312..116B), Den Hartog et al. (2003ApJS..148..543D),
Den Hartog et al. (2006, Cat. J/ApJS/167/292), Lawler et al. (2007,
Cat. J/ApJS/169/120), Lawler et al. (2008ApJS..178...71L),
Lawler et al. (2009, Cat. J/ApJS/182/51), Sneden et al. (2009,
Cat. J/ApJS/182/80), and Hansen et al. (2013A&A...551A..57H). <P
/>(1 data file).
---------------------------------------------------------
Title: The solar gravitational redshift from HARPS-LFC Moon
spectra⋆. A test of the general theory of relativity
Authors: González Hernández, J. I.; Rebolo, R.; Pasquini, L.;
Lo Curto, G.; Molaro, P.; Caffau, E.; Ludwig, H. -G.; Steffen, M.;
Esposito, M.; Suárez Mascareño, A.; Toledo-Padrón, B.; Probst,
R. A.; Hänsch, T. W.; Holzwarth, R.; Manescau, A.; Steinmetz, T.;
Udem, Th.; Wilken, T.
2020A&A...643A.146G Altcode: 2020arXiv200910558G
Context. The general theory of relativity predicts the redshift of
spectral lines in the solar photosphere as a consequence of the
gravitational potential of the Sun. This effect can be measured
from a solar disk-integrated flux spectrum of the Sun's reflected
light on Solar System bodies. <BR /> Aims: The laser frequency comb
(LFC) calibration system attached to the HARPS spectrograph offers
the possibility of performing an accurate measurement of the solar
gravitational redshift (GRS) by observing the Moon or other Solar System
bodies. Here, we analyse the line shift observed in Fe absorption lines
from five high-quality HARPS-LFC spectra of the Moon. <BR /> Methods:
We selected an initial sample of 326 photospheric Fe lines in the
spectral range between 476-585 nm and measured their line positions
and equivalent widths (EWs). Accurate line shifts were derived from
the wavelength position of the core of the lines compared with the
laboratory wavelengths of Fe lines. We also used a CO<SUP>5</SUP>BOLD
3D hydrodynamical model atmosphere of the Sun to compute 3D synthetic
line profiles of a subsample of about 200 spectral Fe lines centred
at their laboratory wavelengths. We fit the observed relatively
weak spectral Fe lines (with EW< 180 mÅ) with the 3D synthetic
profiles. <BR /> Results: Convective motions in the solar photosphere
do not affect the line cores of Fe lines stronger than about ∼150
mÅ. In our sample, only 15 Fe I lines have EWs in the range 150<
EW(mÅ) < 550, providing a measurement of the solar GRS at 639 ±
14 m s<SUP>-1</SUP>, which is consistent with the expected theoretical
value on Earth of ∼633.1 m s<SUP>-1</SUP>. A final sample of about 97
weak Fe lines with EW < 180 mÅ allows us to derive a mean global
line shift of 638 ± 6 m s<SUP>-1</SUP>, which is in agreement with
the theoretical solar GRS. <BR /> Conclusions: These are the most
accurate measurements of the solar GRS obtained thus far. Ultrastable
spectrographs calibrated with the LFC over a larger spectral range,
such as HARPS or ESPRESSO, together with a further improvement on the
laboratory wavelengths, could provide a more robust measurement of the
solar GRS and further testing of 3D hydrodynamical models. <P />Tables
A.1 and A.2 are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr/">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/643/A146">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/643/A146</A>
<P />Based on observations taken with the ESO 3.6 m telescope at La
Silla Observatory, Chile.
---------------------------------------------------------
Title: VizieR Online Data Catalog: MC structure and properties
(Gaia Collaboration+, 2021)
Authors: Gaia Collaboration; Luri, X.; Chemin, L.; Clementini,
G.; Delgado, H. E.; McMillan, P. J.; Romero-Gomez, M.; Balbinot,
E.; Castro-Ginard, A.; Mor, R.; Ripepi, V.; Sarro, L. M.; Cioni,
M. -R. L.; Fabricius, C.; Garofalo, A.; Helmi, A.; Muraveva, T.;
Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.;
Babusiaux, C.; Biermann, M.; Creevey, O. L.; Evans, D. W.; Eyer,
L.; Hutton, A.; Jansen, F.; Jordi, C.; Klioner, S. A.; Lammers, U.;
Lindegren, L.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.;
Sartoretti, P.; Soubiran, C.; Walton, N. A.; Arenou, F.; Bailer-Jones,
C. A. L.; Bastian, U.; Cropper, M.; Drimmel, R.; Katz, D.; Lattanzi,
M. G.; van Leeuwen, F.; Bakker, J.; Castaneda, J.; de Angeli, F.;
Ducourant, C.; Fouesneau, M.; Fremat, Y.; Guerra, R.; Guerrier, A.;
Guiraud, J.; Jean-Antoine Piccolo, A.; Masana, E.; Messineo, R.;
Mowlavi, N.; Nicolas, C.; Nienartowicz, K.; Pailler, F.; Panuzzo,
P.; Riclet, F.; Roux, W.; Seabroke, G. M.; Sordo, R.; Tanga, P.;
Thevenin, F.; Gracia-Abril, G.; Portell, J.; Teyssier, D.; Altmann,
M.; Andrae, R.; Bellas-Velidis, I.; Benson, K.; Berthier, J.;
Blomme, R.; Brugaletta, E.; Burgess, P. W.; Busso, G.; Carry, B.;
Cellino, A.; Cheek, N.; Damerdji, Y.; Davidson, M.; Delchambre, L.;
Dell'Oro, A.; Fernandez-Hernandez, J.; Galluccio, L.; Garcia-Lario,
P.; Garcia-Reinaldos, M.; Gonzalez-Nunez, J.; Gosset, E.; Haigron,
R.; Halbwachs, J. -L.; Hambly, N. C.; Harrison, D. L.; Hatzidimitriou,
D.; Heiter, U.; Hernandez, J.; Hestroffer, D.; Hodgkin, S. T.; Holl,
B.; Janssen, K.; Jevardat de Fombelle, G.; Jordan, S.; Krone-Martins,
A.; Lanzafame, A. C.; Loeffler, W.; Lorca, A.; Manteiga, M.; Marchal,
O.; Marrese, P. M.; Moitinho, A.; Mora, A.; Muinonen, K.; Osborne, P.;
Pancino, E.; Pauwels, T.; Recio-Blanco, A.; Richards, P. J.; Riello,
M.; Rimoldini, L.; Robin, A. C.; Roegiers, T.; Rybizki, J.; Siopis,
C.; Smith, M.; Sozzetti, A.; Ulla, A.; Utrilla, E.; van Leeuwen, M.;
van Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts,
C.; Aguado, J. J.; Ajaj, M.; Altavilla, G.; Alvarez, M. A.; Alvarez
Cid-Fuentes, J.; Alves, J.; Anderson, R. I.; Anglada Varela, E.;
Antoja, T.; Audard, M.; Baines, D.; Baker, S. G.; Balaguer-Nunez,
L.; Balog, Z.; Barache, C.; Barbato, D.; Barros, M.; Barstow, M. A.;
Bartolome, S.; Bassilana, J. -L.; Bauchet, N.; Baudesson-Stella, A.;
Becciani, U.; Bellazzini, M.; Bernet, M.; Bertone, S.; Bianchi, L.;
Blanco-Cuaresma, S.; Boch, T.; Bombrun, A.; Bossini, D.; Bouquillon,
S.; Bragaglia, A.; Bramante, L.; Breedt, E.; Bressan, A.; Brouillet,
N.; Bucciarelli, B.; Burlacu, A.; Busonero, D.; Butkevich, A. G.;
Buzzi, R.; Caffau, E.; Cancelliere, R.; Canovas, H.; Cantat-Gaudin,
T.; Carballo, R.; Carlucci, T.; Carnerero, M. I.; Carrasco, J. M.;
Casamiquela, L.; Castellani, M.; Castro Sampol, P.; Chaoul, L.;
Charlot, P.; Chiavassa, A.; Comoretto, G.; Cooper, W. J.; Cornez,
T.; Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Dafonte, C.;
Dapergolas, A.; David, M.; David, P.; de Laverny, P.; de Luise, F.;
de March, R.; De Ridder, J.; de Souza, R.; de Teodoro, P.; de Torres,
A.; Del Peloso, E. F.; Del Pozo, E.; Delgado, A.; Delisle, J. -B.;
Di Matteo, P.; Diakite, S.; Diener, C.; Distefano, E.; Dolding,
C.; Eappachen, D.; Enke, H.; Esquej, P.; Fabre, C.; Fabrizio, M.;
Faigler, S.; Fedorets, G.; Fernique, P.; Fienga, A.; Figueras, F.;
Fouron, C.; Fragkoudi, F.; Fraile, E.; Franke, F.; Gai, M.; Garabato,
D.; Garcia-Gutierrez, A.; Garcia-Torres, M.; Gavras, P.; Gerlach,
E.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona, S.; Giuffrida, G.;
Gomez, A.; Gonzalez-Santamaria, I.; Gonzalez-Vidal, J. J.; Granvik,
M.; Gutierrez-Sanchez, R.; Guy, L. P.; Hauser, M.; Haywood, M.;
Hidalgo, S. L.; Hilger, T.; Hladczuk, N.; Hobbs, D.; Holland, G.;
Huckle, H. E.; Jasniewicz, G.; Jonker, P. G.; Juaristi Campillo, J.;
Julbe, F.; Karbevska, L.; Kervella, P.; Khanna, S.; Kochoska, A.;
Kontizas, M.; Kordopatis, G.; Korn, A. J.; Kostrzewa-Rutkowska, Z.;
Kruszynska, K.; Lambert, S.; Lanza, A. F.; Lasne, Y.; Le Campion,
J. -F.; Le Fustec, Y.; Lebreton, Y.; Lebzelter, T.; Leccia, S.;
Leclerc, N.; Lecoeur-Taibi, I.; Liao, S.; Licata, E.; Lindstrom,
H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; Madrero Pardo, P.;
Managau, S.; Mann, R. G.; Marchant, J. M.; Marconi, M.; Marcos Santos,
M. M. S.; Marinoni, S.; Marocco, F.; Marshall, D. J.; Martin Polo, L.;
Martin-Fleitas, J. M.; Masip, A.; Massari, D.; Mastrobuono-Battisti,
A.; Mazeh, T.; Messina, S.; Michalik, D.; Millar, N. R.; Mints, A.;
Molina, D.; Molinaro, R.; Molnar, L.; Montegriffo, P.; Morbidelli,
R.; Morel, T.; Morris, D.; Mulone, A. F.; Munoz, D.; Murphy, C. P.;
Musella, I.; Noval, L.; Ordenovic, C.; Orru, G.; Osinde, J.; Pagani,
C.; Pagano, I.; Palaversa, L.; Palicio, P. A.; Panahi, A.; Pawlak,
M.; Penalosa Esteller, X.; Penttilae, A.; Piersimoni, A. M.; Pineau,
F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poretti, E.; Poujoulet, E.;
Prsa, A.; Pulone, L.; Racero, E.; Ragaini, S.; Rainer, M.; Raiteri,
C. M.; Rambaux, N.; Ramos, P.; Ramos-Lerate, M.; Re Fiorentin, P.;
Regibo, S.; Reyle, C.; Riva, A.; Rixon, G.; Robichon, N.; Robin, C.;
Roelens, M.; Rohrbasser, L.; Rowell, N.; Royer, F.; Rybicki, K. A.;
Sadowski, G.; Sagrista Selles, A.; Sahlmann, J.; Salgado, J.; Salguero,
E.; Samaras, N.; Sanchez Gimenez, V.; Sanna, N.; Santovena, R.;
Sarasso, M.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.;
Segransan, D.; Semeux, D.; Siddiqui, H. I.; Siebert, A.; Siltala,
L.; Slezak, E.; Smart, R. L.; Solano, E.; Solitro, F.; Souami, D.;
Souchay, J.; Spagna, A.; Spoto, F.; Steele, I. A.; Steidelmueller,
H.; Stephenson, C. A.; Sueveges, M.; Szabados, L.; Szegedi-Elek, E.;
Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Thuillot, W.;
Tonello, N.; Torra, F.; Torra, J.; Turon, C.; Unger, N.; Vaillant,
M.; van Dillen, E.; Vanel, O.; Vecchiato, A.; Viala, Y.; Vicente,
D.; Voutsinas, S.; Weiler, M.; Wevers, T.; Wyrzykowski, L.; Yoldas, A.;
Yvard, P.; Zhao, H.; Zorec, J.; Zucker, S.; Zurbach, C.; Zwitter, T.
2020yCat..36490007G Altcode:
Tables of the radial profiles of the azimuthal and radial components
of the ordered and random motions of stellar evolutionary phases in
the Large Magellanic Cloud, as inferred from the 3rd Gaia Data Release
(Early Release of 2020/12/03). <P />Each sub-sample of LMC stellar
evolutionary phase is defined in Sect. 2.3 of the article. The file
lmcall.dat is for a sample combining every stellar phases. <P />(9
data files).
---------------------------------------------------------
Title: VizieR Online Data Catalog: Gaia Catalogue of Nearby Stars -
GCNS (Gaia collaboration, 2021)
Authors: Gaia Collaboration; Smart, R. L.; Sarro, L. M.; Rybizki,
J.; Reyle, C.; Robin, A. C.; Hambly, N. C.; Abbas, U.; Barstow,
M. A.; de Bruijne, J. H. J.; Bucciarelli, B.; Carrasco, J. M.;
Cooper, W. J.; Hodgkin, S. T.; Masana, E.; Michalik, D.; Sahlmann,
J.; Sozzetti, A.; Brown, A. G. A.; Vallenari, A.; Prusti, T.;
Babusiaux, C.; Biermann, M.; Creevey, O. L.; Evans, D. W.; Eyer,
L.; Hutton, A.; Jansen, F.; Jordi, C.; Klioner, S. A.; Lammers,
U.; Lindegren, L.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.;
Randich, S.; Sartoretti, P.; Soubiran, C.; Walton, N. A.; Arenou,
F.; Bailer-Jones, C. A. L.; Bastian, U.; Cropper, M.; Drimmel, R.;
Katz, D.; Lattanzi, M. G.; van Leeuwen, F.; Bakker, J.; Castaneda, J.;
de Angeli, F.; Ducourant, C.; Fabricius, C.; Fouesneau, M.; Fremat,
Y.; Guerra, R.; Guerrier, A.; Guiraud, J.; Jean-Antoine Piccolo, A.;
Messineo, R.; Mowlavi, N.; Nicolas, C.; Nienartowicz, K.; Pailler,
F.; Panuzzo, P.; Riclet, F.; Roux, W.; Seabroke, G. M.; Sordo, R.;
Tanga, P.; Thevenin, F.; Gracia-Abril, G.; Portell, J.; Teyssier, D.;
Altmann, M.; Andrae, R.; Bellas-Velidis, I.; Benson, K.; Berthier,
J.; Blomme, R.; Brugaletta, E.; Burgess, P. W.; Busso, G.; Carry, B.;
Cellino, A.; Cheek, N.; Clementini, G.; Damerdji, Y.; Davidson, M.;
Delchambre, L.; Dell'Oro, A.; Fernandez-Hernandez, J.; Galluccio, L.;
Garcia-Lario, P.; Garcia-Reinaldos, M.; Gonzalez-Nunez, J.; Gosset,
E.; Haigron, R.; Halbwachs, J. -L.; Harrison, D. L.; Hatzidimitriou,
D.; Heiter, U.; Hernandez, J.; Hestroffer, D.; Holl, B.; Janssen, K.;
Jevardat de Fombelle, G.; Jordan, S.; Krone-Martins, A.; Lanzafame,
A. C.; Loeffler, W.; Lorca, A.; Manteiga, M.; Marchal, O.; Marrese,
P. M.; Moitinho, A.; Mora, A.; Muinonen, K.; Osborne, P.; Pancino,
E.; Pauwels, T.; Recio-Blanco, A.; Richards, P. J.; Riello, M.;
Rimoldini, L.; Roegiers, T.; Siopis, C.; Smith, M.; Ulla, A.; Utrilla,
E.; van Leeuwen, M.; van Reeven, W.; Abreu Aramburu, A.; Accart, S.;
Aerts, C.; Aguado, J. J.; Ajaj, M.; Altavilla, G.; Alvarez, M. A.;
Alvarez Cid-Fuentes, J.; Alves, J.; Anderson, R. I.; Anglada Varela,
E.; Antoja, T.; Audard, M.; Baines, D.; Baker, S. G.; Balaguer-Nunez,
L.; Balbinot, E.; Balog, Z.; Barache, C.; Barbato, D.; Barros, M.;
Bartolome, S.; Bassilana, J. -L.; Bauchet, N.; Baudesson-Stella, A.;
Becciani, U.; Bellazzini, M.; Bernet, M.; Bertone, S.; Bianchi, L.;
Blanco-Cuaresma, S.; Boch, T.; Bombrun, A.; Bossini, D.; Bouquillon,
S.; Bragaglia, A.; Bramante, L.; Breedt, E.; Bressan, A.; Brouillet,
N.; Burlacu, A.; Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau,
E.; Cancelliere, R.; Canovas, H.; Cantat-Gaudin, T.; Carballo, R.;
Carlucci, T.; Carnerero, M. I.
2020yCat..36490006G Altcode:
We produce a clean and well characterised catalogue of nearby
objects within 100pc of the Sun from the Gaia early third data
release. We characterise the catalogue using the full data release,
and comparisons to other catalogues in literature and simulations. We
started with a sample of objects with a measured parallax of 8mas. For
all candidates we calculate a distance probability function using
Bayesian procedures and mock catalogues for the prediction of the
priors. For each entry using a random forest classifier we attempt
to remove sources with spurious astrometric solutions. <P />>From
this paper we provide the following data files: <P />table1c.dat
(Table1<SUB>GCNS</SUB>cat): Any object with a non-zero probability
of being within 100 pc and not indicated as a spurious astrometric
solutions. We have also included external photometric and radial
velocity data, the probability of reliable astrometry, probability to
be a white dwarf, the distance 1st, 16th, 50th and 84th percentiles,
the positions and velocities in a galactic reference frame. For
questions please email richard.smart(at)inaf.it. <P />table1r.dat
(Table1<SUB>GCNS</SUB>reject): All other entries from the 8mas
sample that were rejected as having a zero probability of being
inside 100pc or indicated as a spurious astrometric solution. This
table has the same format and columns as GCNS_cat.dat. <P />progwd.dat
(ProbWDlt05_ProbGFgt05): A catalogue of 45 sources with low probability
of being a WD in this work (PWD<0.5), but having larger probabilities
in Gentile-Fusillo et al (2019MNRAS.482.4570G, cat. J/MNRAS/482/4570)
(PGF>0.5). For questions please email carrasco(at)fqa.ub.edu. <P
/>table3.dat (Table3_ResolvedStellarSystems): Resolved binary
candidates in the GCNS catalogue as discussed in the section on
stellar multiplicity: resolved systems. For questions please email
ummi.abbas(at)inaf.it or alessandro.sozzetti(at)inaf.it. <P />maglim.dat
(maglim<SUB>hpx5</SUB>percentile): The magnitude percentiles for level
5 healpixels used in the luminosity function determinations. For
questions please email rybizki(at)mpia.de. <P />distpdf.dat
(distance_PDF): The full distance probability density function
calculated in section 2 and used throughout the paper. For questions
please email rybizki(at)mpia.de. <P />missing.dat (missing_10mas):
A list of 1258 objects with published parallaxes greater than 10mas
that are not or have no parallax in EDR3. For questions please email
celine.reyle(at)obs-besancon.fr. <P />hyacomb.dat (Hyades_ComaBer):
A list of 920+212 probable Hyades and ComaBer members in the GCNS
sample. For questions please email daniel.michalik(at)esa.int or
jos.de.bruijne(at)esa.int. <P />(8 data files).
---------------------------------------------------------
Title: Detailed abundances in a sample of very metal-poor stars
Authors: François, P.; Wanajo, S.; Caffau, E.; Prantzos, N.; Aoki,
W.; Aoki, M.; Bonifacio, P.; Spite, M.; Spite, F.
2020A&A...642A..25F Altcode: 2020arXiv200703994F
Context. Unevolved metal-poor stars bore witness to the early
evolution of the Galaxy, and the determination of their detailed
chemical composition is an important tool to understand its chemical
history. The study of their chemical composition can also be used to
constrain the nucleosynthesis of the first generation of supernovae
that enriched the interstellar medium. <BR /> Aims: We aim to observe a
sample of extremely metal-poor star (EMP stars) candidates selected from
the Sloan Digital Sky Survey data release 12 (SDSS DR12) and determine
their chemical composition. <BR /> Methods: We obtained high-resolution
spectra of a sample of five stars using HDS on Subaru telescope and used
standard 1D models to compute the abundances. The stars we analysed
have a metallicity [Fe/H] of between -3.50 and -4.25 dex. <BR />
Results: We confirm that the five metal-poor candidates selected from
low-resolution spectra are very metal poor. We present the discovery
of a new ultra metal-poor star (UMP star) with a metallicity of [Fe/H]
= -4.25 dex (SDSS J1050032.34-241009.7). We measured in this star an
upper limit of lithium (log(Li/H) ≤ 2.0. We found that the four most
metal-poor stars of our sample have a lower lithium abundance than
the Spite plateau lithium value. We obtain upper limits for carbon in
the sample of stars. None of them belong to the high carbon band. We
measured abundances of Mg and Ca in most of the stars and found three
new α-poor stars. <P />Based on data collected at Subaru Telescope,
which is operated by the National Astronomical Observatory of Japan.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Linelist (Hansen+, 2020)
Authors: Hansen, C. J.; Koch, A.; Mashonkina, L.; Magg, M.; Bergemann,
M.; Sitnova, T.; Gallagher, A. J.; Ilyin, I.; Caffau, E.; Zhang,
H. W.; Strassmeier, K. G.; Klessen, R. S.
2020yCat..36430049H Altcode:
Linelist containing wavelength, element and ionisation degree (0 =
neutral, 1 = single ionised), excitation potential [eV], oscillator
strength (loggf), number of stars in the study in which the line
has been detected (limits indicated by <), and finally, hyperfine
structure of oscillator strength indicated by HFS. <P />(1 data file).
---------------------------------------------------------
Title: Gaia Data Release 2. The kinematics of globular clusters and
dwarf galaxies around the Milky Way (Corrigendum)
Authors: Gaia Collaboration; Helmi, A.; van Leeuwen, F.; McMillan,
P. J.; Massari, D.; Antoja, T.; Robin, A. C.; Lindegren, L.;
Bastian, U.; Arenou, F.; Babusiaux, C.; Biermann, M.; Breddels,
M. A.; Hobbs, D.; Jordi, C.; Pancino, E.; Reylé, C.; Veljanoski,
J.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne,
J. H. J.; Bailer-Jones, C. A. L.; Evans, D. W.; Eyer, L.; Jansen,
F.; Klioner, S. A.; Lammers, U.; Luri, X.; Mignard, F.; Panem,
C.; Pourbaix, D.; Randich, S.; Sartoretti, P.; Siddiqui, H. I.;
Soubiran, C.; Walton, N. A.; Cropper, M.; Drimmel, R.; Katz, D.;
Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castañeda, J.; Chaoul,
L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.; Holl, B.;
Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Panuzzo,
P.; Portell, J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thévenin,
F.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Teyssier,
D.; Altmann, M.; Andrae, R.; Audard, M.; Bellas-Velidis, I.; Benson,
K.; Berthier, J.; Blomme, R.; Burgess, P.; Busso, G.; Carry, B.;
Cellino, A.; Clementini, G.; Clotet, M.; Creevey, O.; Davidson,
M.; De Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.;
Fernández-Hernández, J.; Fouesneau, M.; Frémat, Y.; Galluccio, L.;
García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.;
Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.;
Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Löffler, W.;
Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
Mora, A.; Muinonen, K.; Osinde, J.; Pauwels, T.; Petit, J. -M.;
Recio-Blanco, A.; Richards, P. J.; Rimoldini, L.; Sarro, L. M.;
Siopis, C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.; van
Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.;
Altavilla, G.; Álvarez, M. A.; Alvarez, R.; Alves, J.; Anderson,
R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Arcay, B.;
Astraatmadja, T. L.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.;
Balm, P.; Barache, C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem,
P. S.; Barrado, D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz,
S.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.;
Bertone, S.; Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch,
T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon,
S.; Bourda, G.; Bragaglia, A.; Bramante, L.; Bressan, A.; Brouillet,
N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.;
Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere,
R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.;
Carrasco, J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard, A.;
Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza, G.; Costigan, G.;
Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers, J.; Dafonte,
C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; de Laverny,
P.; De Luise, F.; De March, R.; de Martino, D.; de Souza, R.; de
Torres, A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.;
Delgado, H. E.; Di Matteo, P.; Diakite, S.; Diener, C.; Distefano,
E.; Dolding, C.; Drazinos, P.; Durán, J.; Edvardsson, B.; Enke, H.;
Eriksson, K.; Esquej, P.; Eynard Bontemps, G.; Fabre, C.; Fabrizio,
M.; Faigler, S.; Falcão, A. J.; Farràs Casas, M.; Federici, L.;
Fedorets, G.; Fernique, P.; Figueras, F.; Filippi, F.; Findeisen, K.;
Fonti, A.; Fraile, E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti,
S.; Garabato, D.; García-Sedano, F.; Garofalo, A.; Garralda, N.;
Gavel, A.; Gavras, P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore,
G.; Girona, S.; Giuffrida, G.; Glass, F.; Gomes, M.; Granvik, M.;
Gueguen, A.; Guerrier, A.; Guiraud, J.; Gutiérrez-Sánchez, R.;
Haigron, R.; Hatzidimitriou, D.; Hauser, M.; Haywood, M.; Heiter,
U.; Heu, J.; Hilger, T.; Hofmann, W.; Holland, G.; Huckle, H. E.;
Hypki, A.; Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.; Jonker,
P. G.; Juhász, Á. L.; Julbe, F.; Karampelas, A.; Kewley, A.; Klar,
J.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.; Kontizas,
E.; Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.; Koubsky,
P.; Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; López,
M.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant,
J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall, D. J.;
Martino, M.; Marton, G.; Mary, N.; Matijevič, G.; Mazeh, T.; Messina,
S.; Michalik, D.; Millar, N. R.; Molina, D.; Molinaro, R.; Molnár,
L.; Montegriffo, P.; Mor, R.; Morbidelli, R.; Morel, T.; Morris, D.;
Mulone, A. F.; Muraveva, T.; Musella, I.; Nelemans, G.; Nicastro,
L.; Noval, L.; O'Mullane, W.; Ordénovic, C.; Ordóñez-Blanco,
D.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.; Palacin, H.;
Palaversa, L.; Panahi, A.; Pawlak, M.; Piersimoni, A. M.; Pineau,
F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poujoulet, E.; Prša, A.;
Pulone, L.; Racero, E.; Ragaini, S.; Rambaux, N.; Ramos-Lerate, M.;
Regibo, S.; Riclet, F.; Ripepi, V.; Riva, A.; Rivard, A.; Rixon, G.;
Roegiers, T.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer,
F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann,
J.; Salgado, J.; Salguero, E.; Sanna, N.; Santana-Ros, T.; Sarasso,
M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia,
J. C.; Ségransan, D.; Shih, I. -C.; Siltala, L.; Silva, A. F.; Smart,
R. L.; Smith, K. W.; Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto,
S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.;
Steidelmüller, H.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Surdej,
J.; Szabados, L.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran,
G.; Taylor, M. B.; Teixeira, R.; Terrett, D.; Teyssandier, P.;
Thuillot, W.; Titarenko, A.; Torra Clotet, F.; Turon, C.; Ulla, A.;
Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini, G.; Valette, V.;
van Elteren, A.; Van Hemelryck, E.; van Leeuwen, M.; Vaschetto, M.;
Vecchiato, A.; Viala, Y.; Vicente, D.; Vogt, S.; von Essen, C.; Voss,
H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Wertz, O.;
Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Ziaeepour,
H.; Zorec, J.; Zschocke, S.; Zucker, S.; Zurbach, C.; Zwitter, T.
2020A&A...642C...1G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: VizieR Online Data Catalog: The solar gravitational redshift
(Gonzalez Hernandez+, 2020)
Authors: Gonzalez Hernandez, J. I.; Rebolo, R.; Pasquini, L.; Lo Curto,
G.; Molaro, P.; Caffau, E.; Ludwig, H. -G.; Steffen, M.; Esposito,
M.; Suarez Mascarenno, A.; Toledo-Padron, B.; Probst, R. A.; Hansch,
T. W.; Holzwarth, R.; Manescau, A.; Steinmetz, T.; Udem, T.; Wilken, T.
2020yCat..36430146G Altcode:
Line data and velocity shifts of the FeI and FeII lines,
with laboratory wavelengths, λ<SUB>lab</SUB>, from Nave et
al. (1994ApJS...94..221N, 2013ApJS..204....1N) and excitation
potentials, oscillator strengths from the VALD database (Piskunov et
al. 1995A&AS..112..525P). <P />In Table A.1 we provide the mean line
core shifts, v<SUB>core</SUB>obs, measured on the spectral lines from
the observed HARPS-LFC spectra of the MOON and computed with respect to
the original laboratory wavelengths (Nave et al. 1994ApJS...94..221N,
2013ApJS..204....1N). <P />We also give the recalibrated wavelengths,
lambda_nist, computed from recalibrated wavenumber measurements and
Ritz wavelengths, lambda_ritz, computed from recalibrated energy levels,
with their corresponding wavelengths uncertainties, extracted from the
NIST database (Kramida et al. 2019APS..DMPN09004K). <P />In Table A.2,
we give the line core shifts measured on the observed spectral lines,
v<SUB>core</SUB>obs_n, estimated using the recalibrated wavelengths,
lambda_nist, as reference laboratory wavelengths, the 3D profiles,
v<SUB>core,3D, and the global line shifts, v</SUB>fit<SUB>3D</SUB>n,
from fitting the observed spectral lines using 3D profiles, and
corrected using the recalibrated wavelengths lambda_nist as reference
laboratory wavelengths. <P />Wavelengths are given in Angstroms,
wavelength uncertainties in miliAngstroems, excitation potentials in
eV, equivalent widths (EW) in miliAngstroems, and velocity shifts in
m/s. <P />(2 data files).
---------------------------------------------------------
Title: A wide angle view of the Sagittarius dwarf spheroidal
galaxy. II. A CEMP-r/s star in the Sagittarius dwarf spheroidal galaxy
Authors: Sbordone, L.; Hansen, C. J.; Monaco, L.; Cristallo, S.;
Bonifacio, P.; Caffau, E.; Villanova, S.; Amigo, P.
2020A&A...641A.135S Altcode: 2020arXiv200503027S
We report on the discovery and chemical abundance analysis of the
first CEMP-r/s star detected in the Sagittarius dwarf spheroidal
galaxy (Sgr dSph) by means of UVES high-resolution spectra. The
star, found in the outskirts of Sgr dSph, along the major axis of
the main body, is a moderately metal-poor giant (T<SUB>eff</SUB> =
4753 K, log g = 1.75, [Fe/H] = -1.55) with [C/Fe] = 1.13, placing
it in the so-called "high-carbon band", and strong s-process and
r-process enrichment ([Ba/Fe] = 1.4, [Eu/Fe] = 1.01). Abundances of
29 elements from C to Dy were obtained. The chemical pattern appears
to be best fitted by a scenario where an r-process pollution event
pre-enriched the material out of which the star was born as secondary
in a binary system whose primary evolved through the AGB phase,
providing C- and s-process enrichment. <P />Line-by-line abundance
tables are are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr/">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/641/A135">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/641/A135</A>
<P />Based on data collected with UVES at 8.2 m VLT-UT2 (Kueyen)
telescope under ESO programme 083.B-0774. This paper includes data
gathered with the 6.5 m Magellan Telescopes located at Las Campanas
Observatory, Chile.
---------------------------------------------------------
Title: Study of the departures from LTE in the unevolved stars
infrared spectra
Authors: Korotin, S. A.; Andrievsky, S. M.; Caffau, E.; Bonifacio,
P.; Oliva, E.
2020MNRAS.496.2462K Altcode: 2020MNRAS.tmp.1855K; 2020arXiv200610998K
We present a study of departures from Local Thermodynamic Equilibrium
(LTE) in the formation of infrared (IR) lines of Na I, Mg I, Al I,
S I, K I, and Sr II in unevolved stars of spectral types F, G, K
and metallicities around the solar metallicity. The purpose of this
investigation is to identify lines of these species that can be safely
treated with the LTE approximation in the IR spectra of these types of
stars. We employ a set of 40 stars observed with the GIANO spectrograph
at the 3.5 m Telescopio Nazionale Galileo and previously investigated by
Caffau et al. We were able to identify many lines that can be treated
in LTE for all the above-mentioned species, except for Sr II. The
latter species can only be studied using three lines in the J band,
but all three of them display significant departures from LTE. With
our small-size, but high-quality sample, we can determine robustly the
trends of the abundance ratios with metallicity, confirming the trends
apparent from a sample that is larger by several orders of magnitude,
but of lower quality in terms of resolution and S/N ratio.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Sgr dSph CEMP-r/s star abundance
analysis (Sbordone+, 2020)
Authors: Sbordone, L.; Hansen, C. J.; Monaco, L.; Cristallo, S.;
Bonifacio, P.; Caffau, E.; Villanova, S.; Amigo, P.
2020yCat..36410135S Altcode:
These two tables contain the results relative to the fitting of
all the individual spectral features fitted with the MyGIsFOS and
FitProfile automatic codes. The "alllines.dat" table contains the
feature characteristics (e.g. ion abundance fitted through the feature,
starting and ending wavelength...), the fitting results (e.g. the
derived abundance) and a star and feature identifiers.The second table
(allsynth.dat) contain the detailed observed and fitted profiles for
each feature. Each line contains the star and feature identifiers,
the wavelength of that specific "pixel" and the corresponding observed
and fitted normalized fluxes. <P />(2 data files).
---------------------------------------------------------
Title: High-speed stars: Galactic hitchhikers
Authors: Caffau, E.; Monaco, L.; Bonifacio, P.; Sbordone, L.; Haywood,
M.; Spite, M.; Di Matteo, P.; Spite, F.; Mucciarelli, A.; François,
P.; Matas Pinto, A. M.
2020A&A...638A.122C Altcode:
Context. The search for stars born in the very early stages of
the Milky Way star formation history is of paramount importance
in the study of the early Universe since their chemistry carries
irreplaceable information on the conditions in which early star
formation and galaxy buildup took place. The search for these objects
has generally taken the form of expensive surveys for faint extremely
metal-poor stars, the most obvious but not the only candidates
to a very early formation. <BR /> Aims: Thanks to Gaia DR2 radial
velocities and proper motions, we identified 72 bright cool stars
displaying heliocentric transverse velocities in excess of 500 km
s<SUP>-1</SUP>. These objects are most likely members of extreme
outer-halo populations, either formed in the early Milky Way build-up
or accreted from since-destroyed self-gravitating stellar systems. <BR
/> Methods: We analysed low-resolution FORS spectra of the 72 stars
in the sample and derived the abundances of a few elements. Despite
the large uncertainties on the radial velocity determination,
we derived reliable orbital parameters for these objects. <BR />
Results: The stars analysed are mainly slightly metal poor, with a
few very metal-poor stars. Their chemical composition is much more
homogeneous than expected. All the stars have very eccentric halo
orbits, some extending well beyond the expected dimension of the Milky
Way. <BR /> Conclusions: These stars can be the result of a disrupted
small galaxy or they could have been globular cluster members. Age
estimates suggest that some of them are evolved blue stragglers,
now on the subgiant or asymptotic giant branches. <P />Chemical and
kinematic data are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr/">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/638/A122">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/638/A122</A>
<P />Based on observations made with ESO Telescopes at the La Silla
Paranal Observatory under programme ID 104.D-0259.
---------------------------------------------------------
Title: MOONS: The New Multi-Object Spectrograph for the VLT
Authors: Cirasuolo, M.; Fairley, A.; Rees, P.; Gonzalez, O. A.;
Taylor, W.; Maiolino, R.; Afonso, J.; Evans, C.; Flores, H.; Lilly,
S.; Oliva, E.; Paltani, S.; Vanzi, L.; Abreu, M.; Accardo, M.; Adams,
N.; Álvarez Méndez, D.; Amans, J. -P.; Amarantidis, S.; Atek,
H.; Atkinson, D.; Banerji, M.; Barrett, J.; Barrientos, F.; Bauer,
F.; Beard, S.; Béchet, C.; Belfiore, A.; Bellazzini, M.; Benoist,
C.; Best, P.; Biazzo, K.; Black, M.; Boettger, D.; Bonifacio, P.;
Bowler, R.; Bragaglia, A.; Brierley, S.; Brinchmann, J.; Brinkmann,
M.; Buat, V.; Buitrago, F.; Burgarella, D.; Burningham, B.; Buscher,
D.; Cabral, A.; Caffau, E.; Cardoso, L.; Carnall, A.; Carollo, M.;
Castillo, R.; Castignani, G.; Catelan, M.; Cicone, C.; Cimatti, A.;
Cioni, M. -R. L.; Clementini, G.; Cochrane, W.; Coelho, J.; Colling,
M.; Contini, T.; Contreras, R.; Conzelmann, R.; Cresci, G.; Cropper,
M.; Cucciati, O.; Cullen, F.; Cumani, C.; Curti, M.; Da Silva, A.;
Daddi, E.; Dalessandro, E.; Dalessio, F.; Dauvin, L.; Davidson, G.;
de Laverny, P.; Delplancke-Ströbele, F.; De Lucia, G.; Del Vecchio,
C.; Dessauges-Zavadsky, M.; Di Matteo, P.; Dole, H.; Drass, H.;
Dunlop, J.; Dünner, R.; Eales, S.; Ellis, R.; Enriques, B.; Fasola,
G.; Ferguson, A.; Ferruzzi, D.; Fisher, M.; Flores, M.; Fontana, A.;
Forchi, V.; Francois, P.; Franzetti, P.; Gargiulo, A.; Garilli, B.;
Gaudemard, J.; Gieles, M.; Gilmore, G.; Ginolfi, M.; Gomes, J. M.;
Guinouard, I.; Gutierrez, P.; Haigron, R.; Hammer, F.; Hammersley,
P.; Haniff, C.; Harrison, C.; Haywood, M.; Hill, V.; Hubin, N.;
Humphrey, A.; Ibata, R.; Infante, L.; Ives, D.; Ivison, R.; Iwert,
O.; Jablonka, P.; Jakob, G.; Jarvis, M.; King, D.; Kneib, J. -P.;
Laporte, P.; Lawrence, A.; Lee, D.; Li Causi, G.; Lorenzoni, S.;
Lucatello, S.; Luco, Y.; Macleod, A.; Magliocchetti, M.; Magrini,
L.; Mainieri, V.; Maire, C.; Mannucci, F.; Martin, N.; Matute, I.;
Maurogordato, S.; McGee, S.; Mcleod, D.; McLure, R.; McMahon, R.;
Melse, B. -T.; Messias, H.; Mucciarelli, A.; Nisini, B.; Nix, J.;
Norberg, P.; Oesch, P.; Oliveira, A.; Origlia, L.; Padilla, N.; Palsa,
R.; Pancino, E.; Papaderos, P.; Pappalardo, C.; Parry, I.; Pasquini,
L.; Peacock, J.; Pedichini, F.; Pello, R.; Peng, Y.; Pentericci, L.;
Pfuhl, O.; Piazzesi, R.; Popovic, D.; Pozzetti, L.; Puech, M.; Puzia,
T.; Raichoor, A.; Randich, S.; Recio-Blanco, A.; Reis, S.; Reix, F.;
Renzini, A.; Rodrigues, M.; Rojas, F.; Rojas-Arriagada, Á.; Rota,
S.; Royer, F.; Sacco, G.; Sanchez-Janssen, R.; Sanna, N.; Santos, P.;
Sarzi, M.; Schaerer, D.; Schiavon, R.; Schnell, R.; Schultheis, M.;
Scodeggio, M.; Serjeant, S.; Shen, T. -C.; Simmonds, C.; Smoker, J.;
Sobral, D.; Sordet, M.; Spérone, D.; Strachan, J.; Sun, X.; Swinbank,
M.; Tait, G.; Tereno, I.; Tojeiro, R.; Torres, M.; Tosi, M.; Tozzi,
A.; Tresiter, E.; Valenti, E.; Valenzuela Navarro, Á.; Vanzella, E.;
Vergani, S.; Verhamme, A.; Vernet, J.; Vignali, C.; Vinther, J.; Von
Dran, L.; Waring, C.; Watson, S.; Wild, V.; Willesme, B.; Woodward, B.;
Wuyts, S.; Yang, Y.; Zamorani, G.; Zoccali, M.; Bluck, A.; Trussler, J.
2020Msngr.180...10C Altcode: 2020arXiv200900628C
MOONS is the new Multi-Object Optical and Near-infrared Spectrograph
currently under construction for the Very Large Telescope (VLT) at
ESO. This remarkable instrument combines, for the first time, the
collecting power of an 8-m telescope, 1000 fibres with individual
robotic positioners, and both low- and high-resolution simultaneous
spectral coverage across the 0.64-1.8 μm wavelength range. This
facility will provide the astronomical community with a powerful,
world-leading instrument able to serve a wide range of Galactic,
extragalactic and cosmological studies. Construction is now proceeding
full steam ahead and this overview article presents some of the science
goals and the technical description of the MOONS instrument. More
detailed information on the MOONS surveys is provided in the other
dedicated articles in this Messenger issue.
---------------------------------------------------------
Title: MOONS Surveys of the Milky Way and its Satellites
Authors: Gonzalez, O. A.; Mucciarelli, A.; Origlia, L.; Schultheis,
M.; Caffau, E.; Di Matteo, P.; Randich, S.; Recio-Blanco, A.; Zoccali,
M.; Bonifacio, P.; Dalessandro, E.; Schiavon, R. P.; Pancino, E.;
Taylor, W.; Valenti, E.; Rojas-Arriagada, Á.; Sacco, G.; Biazzo, K.;
Bellazzini, M.; Cioni, M. -R. L.; Clementini, G.; Contreras Ramos, R.;
de Laverny, P.; Evans, C.; Haywood, M.; Hill, V.; Ibata, R.; Lucatello,
S.; Magrini, L.; Martin, N.; Nisini, B.; Sanna, N.; Cirasuolo, M.;
Maiolino, R.; Afonso, J.; Lilly, S.; Flores, H.; Oliva, E.; Paltani,
S.; Vanzi, L.
2020Msngr.180...18G Altcode: 2020arXiv200900635G
The study of resolved stellar populations in the Milky Way and
other Local Group galaxies can provide us with a fossil record of
their chemo-dynamical and star-formation histories over timescales
of many billions of years. In the galactic components and stellar
systems of the Milky Way and its satellites, individual stars can
be resolved. Therefore, they represent a unique laboratory in which
to investigate the details of the processes behind the formation and
evolution of the disc and dwarf/irregular galaxies. MOONS at the VLT
represents a unique combination of an efficient infrared multi-object
spectrograph and a large-aperture 8-m-class telescope which will
sample the cool stellar populations of the dense central regions of the
Milky Way and its satellites, delivering accurate radial velocities,
metallicities, and other chemical abundances for several millions
of stars over its lifetime (see Cirasuolo et al., p. 10). MOONS
will observe up to 1000 targets across a 25-arcminute field of view
in the optical and near-infrared (0.6-1.8 µm) simultaneously. A
high-resolution (R ~ 19700) setting in the H band has been designed
for the accurate determination of stellar abundances such as alpha,
light, iron-peak and neutron-capture elements.
---------------------------------------------------------
Title: Improving spectroscopic lithium abundances. Fitting functions
for 3D non-LTE corrections in FGK stars of different metallicity
Authors: Mott, A.; Steffen, M.; Caffau, E.; Strassmeier, K. G.
2020A&A...638A..58M Altcode: 2020arXiv200410803M
Context. Accurate spectroscopic lithium abundances are essential in
addressing a variety of open questions, such as the origin of a uniform
lithium content in the atmospheres of metal-poor stars (Spite plateau)
or the existence of a correlation between the properties of extrasolar
planetary systems and the lithium abundance in the atmosphere of
their host stars. <BR /> Aims: We have developed a tool that allows
the user to improve the accuracy of standard lithium abundance
determinations based on 1D model atmospheres and the assumption of
local thermodynamic equilibrium (LTE) by applying corrections that
account for hydrodynamic (3D) and non-LTE (NLTE) effects in FGK stars
of different metallicity. <BR /> Methods: Based on a grid of CO5BOLD
3D models and associated 1D hydrostatic atmospheres, we computed
three libraries of synthetic spectra of the lithium λ 670.8 nm line
for a wide range of lithium abundances, accounting for detailed line
formation in 3D NLTE, 1D NLTE, and 1D LTE, respectively. The resulting
curves-of-growth were then used to derive 3D NLTE and 1D NLTE lithium
abundance corrections. <BR /> Results: For all metallicities, the
largest corrections are found at the coolest effective temperature,
T<SUB>eff</SUB> = 5000 K. They are mostly positive, up to + 0.2 dex,
for the weakest lines (lithium abundance A(Li)<SUB>1DLTE</SUB> = 1.0),
whereas they become more negative towards lower metallicities, where
they can reach - 0.4 dex for the strongest lines (A(Li)<SUB>1DLTE</SUB>
= 3.0) at [Fe/H] = - 2.0. We demonstrate that 3D and NLTE effects are
small for metal-poor stars on the Spite plateau, leading to errors of at
most ± 0.05 dex if ignored. We present analytical functions evaluating
the 3D NLTE and 1D NLTE corrections as a function of T<SUB>eff</SUB>
[5000…6500 K], log g [3.5…4.5], and LTE lithium abundance A(Li)
[1.0…3.0] for a fixed grid of metallicities [Fe/H] [ - 3.0…0.0]. In
addition, we also provide analytical fitting functions for directly
converting a given lithium abundance into an equivalent width, or vice
versa, a given equivalent width (EW) into a lithium abundance. For
convenience, a Python script is made available that evaluates all
fitting functions for given T<SUB>eff</SUB>, log g, [Fe/H], and A(Li)
or EW. <BR /> Conclusions: By means of the fitting functions developed
in this work, the results of complex 3D and NLTE calculations are
made readily accessible and quickly applicable to large samples of
stars across a wide range of metallicities. Improving the accuracy
of spectroscopic lithium abundance determinations will contribute to
a better understanding of the open questions related to the lithium
content in metal-poor and solar-like stellar atmospheres.
---------------------------------------------------------
Title: Gaia Data Release 2. Kinematics of globular clusters and
dwarf galaxies around the Milky Way (Corrigendum)
Authors: Gaia Collaboration; Helmi, A.; van Leeuwen, F.; McMillan,
P. J.; Massari, D.; Antoja, T.; Robin, A. C.; Lindegren, L.;
Bastian, U.; Arenou, F.; Babusiaux, C.; Biermann, M.; Breddels,
M. A.; Hobbs, D.; Jordi, C.; Pancino, E.; Reylé, C.; Veljanoski,
J.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne,
J. H. J.; Bailer-Jones, C. A. L.; Evans, D. W.; Eyer, L.; Jansen,
F.; Klioner, S. A.; Lammers, U.; Luri, X.; Mignard, F.; Panem,
C.; Pourbaix, D.; Randich, S.; Sartoretti, P.; Siddiqui, H. I.;
Soubiran, C.; Walton, N. A.; Cropper, M.; Drimmel, R.; Katz, D.;
Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castañeda, J.; Chaoul,
L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.; Holl, B.;
Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Panuzzo,
P.; Portell, J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thévenin,
F.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Teyssier,
D.; Altmann, M.; Andrae, R.; Audard, M.; Bellas-Velidis, I.; Benson,
K.; Berthier, J.; Blomme, R.; Burgess, P.; Busso, G.; Carry, B.;
Cellino, A.; Clementini, G.; Clotet, M.; Creevey, O.; Davidson,
M.; De Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.;
Fernández-Hernández, J.; Fouesneau, M.; Frémat, Y.; Galluccio, L.;
García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.;
Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.;
Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Löffler, W.;
Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
Mora, A.; Muinonen, K.; Osinde, J.; Pauwels, T.; Petit, J. -M.;
Recio-Blanco, A.; Richards, P. J.; Rimoldini, L.; Sarro, L. M.;
Siopis, C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.; van
Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.;
Altavilla, G.; Álvarez, M. A.; Alvarez, R.; Alves, J.; Anderson,
R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Arcay, B.;
Astraatmadja, T. L.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.;
Balm, P.; Barache, C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem,
P. S.; Barrado, D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz,
S.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.;
Bertone, S.; Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch,
T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon,
S.; Bourda, G.; Bragaglia, A.; Bramante, L.; Bressan, A.; Brouillet,
N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.;
Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere,
R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.;
Carrasco, J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard, A.;
Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza, G.; Costigan, G.;
Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers, J.; Dafonte,
C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; de Laverny,
P.; De Luise, F.; De March, R.; de Martino, D.; de Souza, R.; de
Torres, A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.;
Delgado, H. E.; Di Matteo, P.; Diakite, S.; Diener, C.; Distefano,
E.; Dolding, C.; Drazinos, P.; Durán, J.; Edvardsson, B.; Enke, H.;
Eriksson, K.; Esquej, P.; Eynard Bontemps, G.; Fabre, C.; Fabrizio,
M.; Faigler, S.; Falcão, A. J.; Farràs Casas, M.; Federici, L.;
Fedorets, G.; Fernique, P.; Figueras, F.; Filippi, F.; Findeisen, K.;
Fonti, A.; Fraile, E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti,
S.; Garabato, D.; García-Sedano, F.; Garofalo, A.; Garralda, N.;
Gavel, A.; Gavras, P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore,
G.; Girona, S.; Giuffrida, G.; Glass, F.; Gomes, M.; Granvik, M.;
Gueguen, A.; Guerrier, A.; Guiraud, J.; Gutiérrez-Sánchez, R.;
Haigron, R.; Hatzidimitriou, D.; Hauser, M.; Haywood, M.; Heiter,
U.; Heu, J.; Hilger, T.; Hofmann, W.; Holland, G.; Huckle, H. E.;
Hypki, A.; Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.; Jonker,
P. G.; Juhász, Á. L.; Julbe, F.; Karampelas, A.; Kewley, A.; Klar,
J.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.; Kontizas,
E.; Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.; Koubsky,
P.; Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; López,
M.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant,
J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall, D. J.;
Martino, M.; Marton, G.; Mary, N.; Matijevič, G.; Mazeh, T.; Messina,
S.; Michalik, D.; Millar, N. R.; Molina, D.; Molinaro, R.; Molnár,
L.; Montegriffo, P.; Mor, R.; Morbidelli, R.; Morel, T.; Morris, D.;
Mulone, A. F.; Muraveva, T.; Musella, I.; Nelemans, G.; Nicastro,
L.; Noval, L.; O'Mullane, W.; Ordénovic, C.; Ordóñez-Blanco,
D.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.; Palacin, H.;
Palaversa, L.; Panahi, A.; Pawlak, M.; Piersimoni, A. M.; Pineau,
F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poujoulet, E.; Prša, A.;
Pulone, L.; Racero, E.; Ragaini, S.; Rambaux, N.; Ramos-Lerate, M.;
Regibo, S.; Riclet, F.; Ripepi, V.; Riva, A.; Rivard, A.; Rixon, G.;
Roegiers, T.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer,
F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann,
J.; Salgado, J.; Salguero, E.; Sanna, N.; Santana-Ros, T.; Sarasso,
M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia,
J. C.; Ségransan, D.; Shih, I. -C.; Siltala, L.; Silva, A. F.; Smart,
R. L.; Smith, K. W.; Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto,
S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.;
Steidelmüller, H.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Surdej,
J.; Szabados, L.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran,
G.; Taylor, M. B.; Teixeira, R.; Terrett, D.; Teyssandier, P.;
Thuillot, W.; Titarenko, A.; Torra Clotet, F.; Turon, C.; Ulla, A.;
Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini, G.; Valette, V.;
van Elteren, A.; Van Hemelryck, E.; van Leeuwen, M.; Vaschetto, M.;
Vecchiato, A.; Viala, Y.; Vicente, D.; Vogt, S.; von Essen, C.; Voss,
H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Wertz, O.;
Wevems, T.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Ziaeepour,
H.; Zorec, J.; Zschocke, S.; Zucker, S.; Zurbach, C.; Zwitter, T.
2020A&A...637C...3G Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Reviving old controversies: is the early Galaxy flat or
round?. Investigations into the early phases of the Milky Way's
formation through stellar kinematics and chemical abundances
Authors: Di Matteo, P.; Spite, M.; Haywood, M.; Bonifacio, P.; Gómez,
A.; Spite, F.; Caffau, E.
2020A&A...636A.115D Altcode: 2019arXiv191013769D
We analysed a set of very metal-poor stars, for which accurate chemical
abundances have been obtained as part of the ESO Large Program "First
stars" in the light of the Gaia DR2 data. The kinematics and orbital
properties of the stars in the sample show they probably belong to the
thick disc, partially heated to halo kinematics, and to the accreted
Gaia Sausage-Enceladus satellite. The continuity of these properties
with stars at both higher ([Fe/H] > -2) and lower metallicities
([Fe/H] < -4.) suggests that the Galaxy at [Fe/H] ≲ -0.5 and down
to at least [Fe/H] ∼ -6 is dominated by these two populations. In
particular, we show that the disc extends continuously from [Fe/H] ≤
-4 (where stars with disc-like kinematics have recently been discovered)
up to [Fe/H] ≥ -2, the metallicity regime of the Galactic thick
disc. An "ultra metal-poor thick disc" does indeed exist, constituting
the extremely metal-poor tail of the canonical Galactic thick disc,
and extending the latter from [Fe/H] ∼ -0.5 up to the most metal-poor
stars discovered in the Galaxy to date. These results suggest that the
disc may be the main, and possibly the only, stellar population that
has formed in the Galaxy at these metallicities. This would mean that
the dissipative collapse that led to the formation of the old Galactic
disc must have been extremely fast. We also discuss these results in the
light of recent simulation efforts made to reproduce the first stages
of Milky Way-type galaxies. <P />Based on observations collected at
the European Organisation for Astronomical Research in the Southern
Hemisphere under ESO programmes 165.N-0276(A) (P.I.: R. Cayrel).
---------------------------------------------------------
Title: The Pristine survey XI: the FORS2 sample
Authors: Caffau, E.; Bonifacio, P.; Sbordone, L.; Matas Pinto, A. M.;
François, P.; Jablonka, P.; Lardo, C.; Martin, N. F.; Starkenburg,
E.; Aguado, D.; González-Hernández, J. I.; Venn, K.; Mashonkina,
L.; Sestito, F.
2020MNRAS.493.4677C Altcode: 2020MNRAS.tmp..556C
Extremely metal-poor (EMP) stars are old objects that mostly formed
very early after the big bang. They are rare and, to select them, we
have to rely on low-resolution spectroscopic or photometric surveys;
specifically the combination of narrow- and broad-band photometry
provides a powerful and time efficient way to select MP stars. The
Pristine photometric survey is using the Canada-France-Hawaii Telescope
MegaCam wide-field imager to obtain narrow-band photometry by utilizing
a filter centred at 395.2 nm on the Ca II-H and -K lines. Gaia DR 2 is
providing us the wide-band photometry as well as parallaxes. Follow-up
observations of MP candidates allowed us to improve our photometric
calibrations. In this paper of the series we analyse MP stars observed
with FORS2 at VLT. We demonstrate the Pristine calibration adopted in
this work to be able to provide metallicities accurate to ±0.3 dex for
MP giant stars with good parallaxes, while it performs poorly for dwarf
and turn-off stars, whatever the accuracy on the parallaxes. We find
some MP and very MP stars that are not enhanced in α elements. Such
stars have already been found in several other searches, and a higher
resolution follow-up of our sample would be useful to put our findings
on a firmer ground. This sample of stars analysed has a low fraction of
carbon-enhanced MP stars, regardless of the definition adopted. This
deficiency could indicate a small sensitivity of the Pristine filter
to carbon abundance, issue to be addressed in the future.
---------------------------------------------------------
Title: VizieR Online Data Catalog: High-speed stars. Galactic
hitchhikers (Caffau+, 2020)
Authors: Caffau, E.; Monaco, L.; Bonifacio, P.; Sbordone, L.; Haywood,
M.; Spite, M.; Di Matteo, P.; Spite, F.; Mucciarelli, A.; Francois,
P.; Matas Pinto, A. M.
2020yCat..36380122C Altcode:
From the Gaia DR2 catalogue, we selected stars with transverse velocity
higher than 500km/s, in the G magnitude range 14-14.5. Further
constraints were put on right ascension to ensure observability in
European Southern Observatory (ESO) period 104 (0h<=RA<=16h
or RA>=20) and on declination (DE<=-25) to privilege a south
pointing. The latter constraint was set in order to ensure that the VLT
could observe our targets even in the event of fairly strong northern
wind. In this way we were able to ensure observations of stars that
were not too far away, and as a consequence with relatively small
uncertainties on parallaxes and proper motions, and of bright objects
for an 8 m class telescope, allowing good quality observations even
in bad weather conditions. <P />All 72 stars were observed during
ESO period 104. <P />In the kinematical and chemical investigations,
we assumed that all stars are single. <P />(3 data files).
---------------------------------------------------------
Title: The Pristine survey - IX. CFHT ESPaDOnS spectroscopic analysis
of 115 bright metal-poor candidate stars
Authors: Venn, Kim A.; Kielty, Collin L.; Sestito, Federico;
Starkenburg, Else; Martin, Nicolas; Aguado, David S.; Arentsen, Anke;
Bonifacio, Piercarlo; Caffau, Elisabetta; Hill, Vanessa; Jablonka,
Pascale; Lardo, Carmela; Mashonkina, Lyudmilla; Navarro, Julio F.;
Sneden, Chris; Thomas, Guillaume; Youakim, Kris; González-Hernández,
Jonay I.; Sánchez Janssen, Rubén; Carlberg, Ray; Malhan, Khyati
2020MNRAS.492.3241V Altcode: 2019MNRAS.tmp.3190V; 2019arXiv191006340V
A chemo-dynamical analysis of 115 metal-poor candidate stars selected
from the narrow-band Pristine photometric survey is presented based
on CFHT high-resolution ESPaDOnS spectroscopy. We have discovered 28
new bright (V < 15) stars with [Fe/H] < -2.5 and 5 with [Fe/H]
< -3.0 for success rates of 40 (28/70) and 19 per cent (5/27),
respectively. A detailed model atmosphere analysis is carried out
for the 28 new metal-poor stars. Stellar parameters were determined
from SDSS photometric colours, Gaia DR2 parallaxes, MESA/MIST stellar
isochrones, and the initial Pristine survey metallicities, following
a Bayesian inference method. Chemical abundances are determined for 10
elements (Na, Mg, Ca, Sc, Ti, Cr, Fe, Ni, Y, and Ba). Most stars show
chemical abundance patterns that are similar to the normal metal-poor
stars in the Galactic halo; however, we also report the discoveries of
a new r-process-rich star, a new CEMP-s candidate with [Y/Ba] > 0,
and a metal-poor star with very low [Mg/Fe]. The kinematics and orbits
for all of the highly probable metal-poor candidates are determined
by combining our precision radial velocities with Gaia DR2 proper
motions. Some stars show unusual kinematics for their chemistries,
including planar orbits, unbound orbits, and highly elliptical orbits
that plunge deeply into the Galactic bulge (R<SUB>peri</SUB> < 0.5
kpc); also, eight stars have orbital energies and actions consistent
with the Gaia-Enceladus accretion event. This paper contributes to our
understanding of the complex chemo-dynamics of the metal-poor Galaxy,
and increases the number of known bright metal-poor stars available
for detailed nucleosynthetic studies.
---------------------------------------------------------
Title: Erratum: The Pristine survey - VI. The first three years
of medium-resolution follow-up spectroscopy of Pristine EMP star
candidates
Authors: Aguado, David S.; Youakim, Kris; González Hernández,
Jonay I.; Allende Prieto, Carlos; Starkenburg, Else; Martin, Nicolas;
Bonifacio, Piercarlo; Arentsen, Anke; Caffau, Elisabetta; Peralta
de Arriba, Luis; Sestito, Federico; Garcia-Dias, Rafael; Fantin,
Nicholas; Hill, Vanessa; Jablonca, Pascale; Jahandar, Farbod; Kielty,
Collin; Longeard, Nicolas; Lucchesi, Romain; Sánchez-Janssen, Rubén;
Osorio, Yeisson; Palicio, Pedro A.; Tolstoy, Eline; Wilson, Thomas
G.; Côté, Patrick; Kordopatis, Georges; Lardo, Carmela; Navarro,
Julio F.; Thomas, Guillaume F.; Venn, Kim
2020MNRAS.491.5299A Altcode:
No abstract at ADS
---------------------------------------------------------
Title: ESPRESSO highlights the binary nature of the ultra-metal-poor
giant HE 0107-5240
Authors: Bonifacio, P.; Molaro, P.; Adibekyan, V.; Aguado, D.; Alibert,
Y.; Allende Prieto, C.; Caffau, E.; Cristiani, S.; Cupani, G.; Di
Marcantonio, P.; D'Odorico, V.; Ehrenreich, D.; Figueira, P.; Genova,
R.; González Hernández, J. I.; Lo Curto, G.; Lovis, C.; Martins,
C. J. A. P.; Mehner, A.; Micela, G.; Monaco, L.; Nunes, N. J.; Pepe,
F. A.; Poretti, E.; Rebolo, R.; Santos, N. C.; Saviane, I.; Sousa, S.;
Sozzetti, A.; Suarez-Mascareño, A.; Udry, S.; Zapatero-Osorio, M. R.
2020A&A...633A.129B Altcode:
Context. The vast majority of the known stars of ultra low metallicity
([Fe/H] < -4.5) are known to be enhanced in carbon, and belong to
the "low-carbon band" (A(C) = log(C/H)+12 ≤ 7.6). It is generally,
although not universally, accepted that this peculiar chemical
composition reflects the chemical composition of the gas cloud out
of which these stars were formed. The first ultra-metal-poor star
discovered, HE 0107-5240, is also enhanced in carbon and belongs to the
"low-carbon band". It has recently been claimed to be a long-period
binary, based on radial velocity measurements. It has also been claimed
that this binarity may explain its peculiar composition as being due
to mass transfer from a former AGB companion. Theoretically, low-mass
ratios in binary systems are much more favoured amongst Pop III stars
than they are amongst solar-metallicity stars. Any constraint on
the mass ratio of a system of such low metallicity would shed light
on the star formation mechanisms in this metallicity regime. <BR />
Aims: We acquired one high precision spectrum with ESPRESSO in order
to check the reality of the radial velocity variations. In addition we
analysed all the spectra of this star in the ESO archive obtained with
UVES to have a set of homogenously measured radial velocities. <BR />
Methods: The radial velocities were measured using cross correlation
against a synthetic spectrum template. Due to the weakness of metallic
lines in this star, the signal comes only from the CH molecular lines
of the G-band. <BR /> Results: The measurement obtained in 2018 from an
ESPRESSO spectrum demonstrates unambiguously that the radial velocity of
HE 0107-5240 has increased from 2001 to 2018. Closer inspection of the
measurements based on UVES spectra in the interval 2001-2006 show that
there is a 96% probability that the radial velocity correlates with
time, hence the radial velocity variations can already be suspected
from the UVES spectra alone. <BR /> Conclusions: We confirm the
earlier claims of radial velocity variations in HE 0107-5240. The
simplest explanation of such variations is that the star is indeed
in a binary system with a long period. The nature of the companion
is unconstrained and we consider it is equally probable that it is
an unevolved companion or a white dwarf. Continued monitoring of the
radial velocities of this star is strongly encouraged. <P />Tables
1 and 2 are also available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr/">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/633/A129">http://cdsarc.</A><A
href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/633/A129">http://u-strasbg.fr/viz-bin/cat/J/A+A/633/A129</A>
---------------------------------------------------------
Title: VizieR Online Data Catalog: ESPRESSO radial velocities of
HE0107-5240 (Bonifacio+, 2020)
Authors: Bonifacio, P.; Molaro, P.; Adibekyan, V.; Aguado, D.; Alibert,
Y.; Allende Prieto, C.; Caffau, E.; Cristiani, S.; Cupani, G.; di
Marcantonio, P.; D'Odorico, V.; Ehrenreich, D.; Figueira, P.; Genova,
R.; Gonzalez Hernandez, J. I.; Lo Curto, G.; Lovis, C.; Martins,
C. J. A. P.; Mehner, A.; Micela, G.; Monaco, L.; Nunes, N. J.; Pepe,
F. A.; Poretti, E.; Rebolo, R.; Santos, N. C.; Saviane, I.; Sousa, S.;
Sozzetti, A.; Suarez-Mascareno, A.; Udry, S.; Zapatero-Osorio, M. R.
2020yCat..36330129B Altcode:
A new measurement of the radial velocity of the ultra-metal-poor star
HE 0107-5240 is derived using a high resolution spectrum obtained with
the Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic
Observations (ESPRESSO). In the high resolution mode there are two
fibres with a core diameter of 140um that corresponds to 1.0" on the
sky. HE 0107-5240 was observed on September 3, 2018. The new measurement
is put into context with measurements derived using spectra taken in
the last 17 years and confirms the variation in radial velocity of
this star over this period. <P />(2 data files).
---------------------------------------------------------
Title: The Pristine survey - VI. The first three years of
medium-resolution follow-up spectroscopy of Pristine EMP star
candidates
Authors: Aguado, David S.; Youakim, Kris; González Hernández,
Jonay I.; Allende Prieto, Carlos; Starkenburg, Else; Martin, Nicolas;
Bonifacio, Piercarlo; Arentsen, Anke; Caffau, Elisabetta; Peralta
de Arriba, Luis; Sestito, Federico; Garcia-Dias, Rafael; Fantin,
Nicholas; Hill, Vanessa; Jablonca, Pascale; Jahandar, Farbod; Kielty,
Collin; Longeard, Nicolas; Lucchesi, Romain; Sánchez-Janssen, Rubén;
Osorio, Yeisson; Palicio, Pedro A.; Tolstoy, Eline; Wilson, Thomas
G.; Côté, Patrick; Kordopatis, Georges; Lardo, Carmela; Navarro,
Julio F.; Thomas, Guillaume F.; Venn, Kim
2019MNRAS.490.2241A Altcode: 2019MNRAS.tmp.2271A; 2019arXiv190908138A
We present the results of a 3-yr long, medium-resolution spectroscopic
campaign aimed at identifying very metal-poor stars from candidates
selected with the CaHK, metallicity-sensitive Pristine survey. The
catalogue consists of a total of 1007 stars, and includes 146
rediscoveries of metal-poor stars already presented in previous
surveys, 707 new very metal-poor stars with [Fe/H] < -2.0, and
95 new extremely metal-poor stars with [Fe/H] < -3.0. We provide
a spectroscopic [Fe/H] for every star in the catalogue, and [C/Fe]
measurements for a subset of the stars (10 per cent with [Fe/H] <
-3 and 24 per cent with -3 < [Fe/H] < -2) for which a carbon
determination is possible, contingent mainly on the carbon abundance,
effective temperature and signal-to-noise ratio of the stellar
spectra. We find an average carbon enhancement fraction ([C/Fe] ≥
+0.7) of 41 ± 4 per cent for stars with -3 < [Fe/H] < -2 and
58 ± 14 per cent for stars with [Fe/H] < -3, and report updated
success rates for the Pristine survey of 56 per cent and 23 per cent to
recover stars with [Fe/H] < -2.5 and < -3, respectively. Finally,
we discuss the current status of the survey and its preparation for
providing targets to upcoming multi-object spectroscopic surveys such
as William Herschel Telescope Enhanced Area Velocity Explorer.
---------------------------------------------------------
Title: A wide angle chemical survey of the Sagittarius dwarf
Spheroidal galaxy
Authors: Sbordone, L.; Monaco, L.; Duffau, S.; Bonifacio, P.;
Caffau, E.
2019IAUS..344...42S Altcode:
We present the status of an ongoing project to map the detailed
chemical abundances of stars across the main body of the Sagittarius
dwarf Spheroidal galaxy (Sgr dSph). The Sgr dSph is the closest known
dwarf galaxy, and is being tidally destroyed by its interaction with
the Milky Way (MW), leaving behind a massive stellar stream. Sgr dSph
is a chemically outstanding object, with peculiar abundance ratios,
clear center-outskirts abundance gradients, and spanning more than 3
orders of magnitude in metallicity. We present here detailed abundances
from UVES@VLT spectra for more than 50 giants across 8 fields along
the major and minor axes of Sgr dSph, and 5 more outside the galaxy
main body, but possibly associated to its stellar stream.
---------------------------------------------------------
Title: Probing the existence of very massive first stars
Authors: Salvadori, S.; Bonifacio, P.; Caffau, E.; Korotin, S.;
Andreevsky, S.; Spite, M.; Skúladóttir, Á.
2019MNRAS.487.4261S Altcode: 2019MNRAS.tmp.1406S; 2019arXiv190600994S
We present a novel approach aimed at identifying the key
chemical elements to search for the (missing) descendants of
very massive first stars exploding as pair instability supernovae
(PISN). Our simple and general method consists in a parametric study
accounting for the unknowns related to early cosmic star formation
and metal-enrichment. Our approach allow us to define the most likely
[Fe/H] and abundance ratios of long-lived stars born in interstellar
media polluted by the nucleosynthetic products of PISN at a {> } 90{{
per cent}}, 70{{ per cent}}, and 50{{ per cent}} level. In agreement
with previous works, we show that the descendants of very massive first
stars can be most likely found at [Fe/H] ≈ -2. Further, we demonstrate
that to search for an underabundance of [(N, Cu, Zn)/Fe] < 0 is
the key to identify these rare descendants. The `killing elements'
N, Zn, and Cu are not produced by PISN, so that their sub-Solar
abundance with respect to iron persists in environments polluted by
further generations of normal core-collapse supernovae up to a 50{{
per cent}} level. We show that the star BD+80° 245, which has [Fe/H] =
-2.2, [N/Fe] = -0.79, [Cu/Fe] = -0.75, and [Zn/Fe] = -0.12 can be the
smoking gun of the chemical imprint from very massive first stars. To
this end we acquired new spectra for BD+80° 245 and re-analysed those
available from the literature accounting for non-local thermodynamic
equilibrium corrections for Cu. We discuss how to find more of these
missing descendants in ongoing and future surveys to tightly constrain
the mass distribution of the first stars.
---------------------------------------------------------
Title: The CEMP star SDSS J0222-0313: the first evidence of proton
ingestion in very low-metallicity AGB stars?
Authors: Caffau, E.; Monaco, L.; Bonifacio, P.; Korotin, S.;
Andrievsky, S.; Cristallo, S.; Spite, M.; Spite, F.; Sbordone, L.;
François, P.; Cescutti, G.; Salvadori, S.
2019A&A...628A..46C Altcode:
Context. Carbon-enhanced metal-poor (CEMP) stars are common objects
in the metal-poor regime. The lower the metallicity we look at, the
larger the fraction of CEMP stars with respect to metal-poor stars
with no enhancement in carbon. The chemical pattern of CEMP stars is
diversified, strongly suggesting a different origin of the C enhancement
in the different types of CEMP stars. <BR /> Aims: We selected a CEMP
star, SDSS J0222-0313, with a known high carbon abundance and, from
a low-resolution analysis, a strong enhancement in neutron-capture
elements of the first peak (Sr and Y) and of the second peak (Ba). The
peculiarity of this object is a greater overabundance (with respect to
iron) of the first s-process peak than the second s-process peak. <BR
/> Methods: We analysed a high-resolution spectrum obtained with the
Mike spectrograph at the Clay Magellan 6.5 m telescope in order to
derive the detailed chemical composition of this star. <BR /> Results:
We confirmed the chemical pattern we expected; we derived abundances for
a total of 18 elements and significant upper limits. <BR /> Conclusions:
We conclude that this star is a carbon-enhanced metal-poor star enriched
in elements produced by s-process (CEMP-s), whose enhancement in heavy
elements is due to mass transfer from the more evolved companion in
its asymptotic giant branch (AGB) phase. The abundances imply that
the evolved companion had a low main sequence mass and it suggests
that it experienced a proton ingestion episode at the beginning of
its AGB phase. <P />Based on observations collected with Mike at the
Magellan-II (Clay) telescope at the Las Campanas Observatory under
programme CN2018B-5.
---------------------------------------------------------
Title: The <SUP>6</SUP>Li/<SUP>7</SUP>Li isotopic ratio in the
metal-poor binary CS22876-032
Authors: González Hernández, J. I.; Bonifacio, P.; Caffau, E.;
Ludwig, H. -G.; Steffen, M.; Monaco, L.; Cayrel, R.
2019A&A...628A.111G Altcode: 2019arXiv190705109G
<BR /> Aims: We present high-resolution and high-quality UVES
spectroscopic data of the metal-poor double-lined spectroscopic binary
CS 22876-032 ([Fe/H] approximately -3.7 dex). Our goal is to derive
the <SUP>6</SUP>Li/<SUP>7</SUP>Li isotopic ratio by analysing the
Li I λ 670.8 nm doublet. <BR /> Methods: We co-added all 28 useful
spectra normalised and corrected for radial velocity to the rest frame
of the primary star. We fitted the Li profile with a grid of the 3D
non-local thermodynamic equilibrium (NLTE) synthetic spectra to take
into account the line profile asymmetries induced by stellar convection,
and performed Monte Carlo simulations to evaluate the uncertainty of
the fit of the Li line profile. <BR /> Results: We checked that the
veiling factor does not affect the derived isotopic ratio, <SUP>6</SUP>
Li/<SUP>7</SUP>Li, and only modifies the Li abundance, A(Li), by
about 0.15 dex. The best fit of the Li profile of the primary star
provides A(Li) = 2.17 ± 0.01 dex and <SUP>6</SUP> Li/<SUP>7</SUP>Li =
8<SUB>-5</SUB><SUP>+2</SUP>% at 68% confidence level. In addition, we
improved the Li abundance of the secondary star at A(Li) = 1.55 ± 0.04
dex, which is about 0.6 dex lower than that of the primary star. <BR
/> Conclusions: The analysis of the Li profile of the primary star is
consistent with no detection of <SUP>6</SUP> Li and provides an upper
limit to the isotopic ratio of <SUP>6</SUP> Li/<SUP>7</SUP>Li <
10% at this very low metallicity, about 0.5 dex lower in metallicity
than previous attempts for detection of <SUP>6</SUP> Li in extremely
metal poor stars. These results do not solve or worsen the cosmological
<SUP>7</SUP> Li problem, nor do they support the need for non-standard
<SUP>6</SUP>Li production in the early Universe. <P />The two averaged
spectra are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/628/A111">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/628/A111</A>Based
on observations made with the Very Large Telescope (VLT) at ESO Paranal
Observatory, Chile, Programme 080.D-0333.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Li in BPS CS22876-032 spectrum
(Gonzalez Hernandez+, 2019)
Authors: Gonzalez Hernandez, J. I.; Bonifacio, P.; Caffau, E.; Ludwig,
H. -G.; Steffen, M.; Monaco, L.; Cayrel, R.
2019yCat..36280111G Altcode:
Average co-added, rebinned spectra in the region around the LiI 670.8nm
resonance line of the two stellar components of the metal-poor binary
CS 22876-032 A and CS 22876-032 B. For each star, wavelength, normalised
flux and flux error are given. <P />(2 data files).
---------------------------------------------------------
Title: The Pristine survey - V. A bright star sample observed
with SOPHIE
Authors: Bonifacio, P.; Caffau, E.; Sestito, F.; Lardo, C.; Martin,
N. F.; Starkenburg, E.; Sbordone, L.; François, P.; Jablonka,
P.; Henden, A. A.; Salvadori, S.; González Hernández, J. I.;
Aguado, D. S.; Hill, V.; Venn, K.; Navarro, J. F.; Arentsen, A.;
Sanchez-Janssen, R.; Carlberg, R.
2019MNRAS.487.3797B Altcode: 2019MNRAS.tmp.1324B
With the aim of probing the properties of the bright end of the
Pristine survey and its effectiveness in selecting metal-poor stars,
we selected a sample of bright candidate metal-poor stars combining
Pristine CaHK photometry with APASS gi photometry, before the Gaia
second data release became available. These stars were observed with
the SOPHIE spectrograph at the 1.93 m telescope of Observatoire de
Haute Provence and we used photometry and parallaxes from Gaia DR2
to derive their atmospheric parameters. Chemical abundances were
determined from the spectra for 40 stars of the sample. Eight stars
were confirmed to be very metal-poor ([Fe/H] < -2.0), as expected
from the photometric estimate. No star was found with [Fe/H] <
-3.0, although for nine stars the photometric estimate was below this
value. Three multiple systems are identified from their multipeaked
cross-correlation functions. Two metal-poor stars with [Fe/H] ≈
-1.0 have an age estimate of about 4 Gyr. Accretion from a satellite
galaxy is a possible explanation for these `young metal-poor stars',
but they could also be field blue stragglers. Galactic orbits for our
sample of stars allowed us to divide them into three classes that we
label `Halo', `Thick', and `Thin' and tentatively identify as halo,
thick disc, and thin disc. We present a new method for deriving
photometric metallicities, effective temperatures, and surface
gravities by combining Gaia parallaxes, photometry, and Pristine CaHK
photometry. Comparison with spectroscopic metallicities shows a very
good agreement and suggests that we can further improve the efficiency
of Pristine CaHK in selecting metal-poor stars.
---------------------------------------------------------
Title: Analysis of surface effect on solar-like oscillation
frequencies using 3D hydrodynamical models
Authors: Sonoi, T.; Samadi, R.; Belkacem, K.; Ludwig, H. -G.; Caffau,
E.; Mosser, B.
2019EAS....82..253S Altcode:
We evaluate the frequency difference between standard stellar
models and models patched with 3D hydrodynamical models across the
T<SUB>eff</SUB>-g plane. It allows us to constrain frequency corrections
for surface effect. The coefficients in the correction functionals are
thus provided as functions of effective temperature and surface gravity.
---------------------------------------------------------
Title: Extremely metal-poor stars: the need for UV spectra
Authors: Bonifacio, Piercarlo; Caffau, Elisabetta; Spite, Monique
2019BAAS...51c.546B Altcode: 2019arXiv190305666B; 2019astro2020T.546B
Extremely metal-poor stars are the fossil record of the gas in the
pristine Universe. They offer us the opportunity to understand the mass
distribution and nucleosynthetic properties of the First generation
of stars. UV spectra provide access to information not available in
other spectral ranges.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Pristine survey II. Bright stars
abundances (Caffau+, 2017)
Authors: Caffau, E.; Bonifacio, P.; Starkenburg, E.; Martin, N.;
Youakim, K.; Henden, A. A.; Gonzalez Hernandez, J. I.; Aguado, D. S.;
Allende Prieto, C.; Venn, K.; Jablonka, P.
2019yCat.113380686C Altcode:
Atmospheric parameters and radial velocities for 27 stars and detailed
abundances for 23 stars. <P />(2 data files).
---------------------------------------------------------
Title: The Detailed Science Case for the Maunakea Spectroscopic
Explorer, 2019 edition
Authors: The MSE Science Team; Babusiaux, Carine; Bergemann, Maria;
Burgasser, Adam; Ellison, Sara; Haggard, Daryl; Huber, Daniel;
Kaplinghat, Manoj; Li, Ting; Marshall, Jennifer; Martell, Sarah;
McConnachie, Alan; Percival, Will; Robotham, Aaron; Shen, Yue;
Thirupathi, Sivarani; Tran, Kim-Vy; Yeche, Christophe; Yong, David;
Adibekyan, Vardan; Silva Aguirre, Victor; Angelou, George; Asplund,
Martin; Balogh, Michael; Banerjee, Projjwal; Bannister, Michele;
Barría, Daniela; Battaglia, Giuseppina; Bayo, Amelia; Bechtol,
Keith; Beck, Paul G.; Beers, Timothy C.; Bellinger, Earl P.; Berg,
Trystyn; Bestenlehner, Joachim M.; Bilicki, Maciej; Bitsch, Bertram;
Bland-Hawthorn, Joss; Bolton, Adam S.; Boselli, Alessandro; Bovy,
Jo; Bragaglia, Angela; Buzasi, Derek; Caffau, Elisabetta; Cami, Jan;
Carleton, Timothy; Casagrande, Luca; Cassisi, Santi; Catelan, Márcio;
Chang, Chihway; Cortese, Luca; Damjanov, Ivana; Davies, Luke J. M.;
de Grijs, Richard; de Rosa, Gisella; Deason, Alis; di Matteo, Paola;
Drlica-Wagner, Alex; Erkal, Denis; Escorza, Ana; Ferrarese, Laura;
Fleming, Scott W.; Font-Ribera, Andreu; Freeman, Ken; Gänsicke,
Boris T.; Gabdeev, Maksim; Gallagher, Sarah; Gandolfi, Davide; García,
Rafael A.; Gaulme, Patrick; Geha, Marla; Gennaro, Mario; Gieles, Mark;
Gilbert, Karoline; Gordon, Yjan; Goswami, Aruna; Greco, Johnny P.;
Grillmair, Carl; Guiglion, Guillaume; Hénault-Brunet, Vincent;
Hall, Patrick; Handler, Gerald; Hansen, Terese; Hathi, Nimish;
Hatzidimitriou, Despina; Haywood, Misha; Hernández Santisteban,
Juan V.; Hillenbrand, Lynne; Hopkins, Andrew M.; Howlett, Cullan;
Hudson, Michael J.; Ibata, Rodrigo; Ilić, Dragana; Jablonka,
Pascale; Ji, Alexander; Jiang, Linhua; Juneau, Stephanie; Karakas,
Amanda; Karinkuzhi, Drisya; Kim, Stacy Y.; Kong, Xu; Konstantopoulos,
Iraklis; Krogager, Jens-Kristian; Lagos, Claudia; Lallement, Rosine;
Laporte, Chervin; Lebreton, Yveline; Lee, Khee-Gan; Lewis, Geraint F.;
Lianou, Sophia; Liu, Xin; Lodieu, Nicolas; Loveday, Jon; Mészáros,
Szabolcs; Makler, Martin; Mao, Yao-Yuan; Marchesini, Danilo; Martin,
Nicolas; Mateo, Mario; Melis, Carl; Merle, Thibault; Miglio, Andrea;
Gohar Mohammad, Faizan; Molaverdikhani, Karan; Monier, Richard;
Morel, Thierry; Mosser, Benoit; Nataf, David; Necib, Lina; Neilson,
Hilding R.; Newman, Jeffrey A.; Nierenberg, A. M.; Nord, Brian;
Noterdaeme, Pasquier; O'Dea, Chris; Oshagh, Mahmoudreza; Pace, Andrew
B.; Palanque-Delabrouille, Nathalie; Pandey, Gajendra; Parker, Laura
C.; Pawlowski, Marcel S.; Peter, Annika H. G.; Petitjean, Patrick;
Petric, Andreea; Placco, Vinicius; Popović, Luka Č.; Price-Whelan,
Adrian M.; Prsa, Andrej; Ravindranath, Swara; Rich, R. Michael; Ruan,
John; Rybizki, Jan; Sakari, Charli; Sanderson, Robyn E.; Schiavon,
Ricardo; Schimd, Carlo; Serenelli, Aldo; Siebert, Arnaud; Siudek,
Malgorzata; Smiljanic, Rodolfo; Smith, Daniel; Sobeck, Jennifer;
Starkenburg, Else; Stello, Dennis; Szabó, Gyula M.; Szabo, Robert;
Taylor, Matthew A.; Thanjavur, Karun; Thomas, Guillaume; Tollerud,
Erik; Toonen, Silvia; Tremblay, Pier-Emmanuel; Tresse, Laurence;
Tsantaki, Maria; Valentini, Marica; Van Eck, Sophie; Variu, Andrei;
Venn, Kim; Villaver, Eva; Walker, Matthew G.; Wang, Yiping; Wang,
Yuting; Wilson, Michael J.; Wright, Nicolas; Xu, Siyi; Yildiz,
Mutlu; Zhang, Huawei; Zwintz, Konstanze; Anguiano, Borja; Bedell,
Megan; Chaplin, William; Collet, Remo; Cuillandre, Jean-Charles;
Duc, Pierre-Alain; Flagey, Nicolas; Hermes, JJ; Hill, Alexis;
Kamath, Devika; Laychak, Mary Beth; Małek, Katarzyna; Marley, Mark;
Sheinis, Andy; Simons, Doug; Sousa, Sérgio G.; Szeto, Kei; Ting,
Yuan-Sen; Vegetti, Simona; Wells, Lisa; Babas, Ferdinand; Bauman,
Steve; Bosselli, Alessandro; Côté, Pat; Colless, Matthew; Comparat,
Johan; Courtois, Helene; Crampton, David; Croom, Scott; Davies, Luke;
de Grijs, Richard; Denny, Kelly; Devost, Daniel; di Matteo, Paola;
Driver, Simon; Fernandez-Lorenzo, Mirian; Guhathakurta, Raja; Han,
Zhanwen; Higgs, Clare; Hill, Vanessa; Ho, Kevin; Hopkins, Andrew;
Hudson, Mike; Ibata, Rodrigo; Isani, Sidik; Jarvis, Matt; Johnson,
Andrew; Jullo, Eric; Kaiser, Nick; Kneib, Jean-Paul; Koda, Jun;
Koshy, George; Mignot, Shan; Murowinski, Rick; Newman, Jeff; Nusser,
Adi; Pancoast, Anna; Peng, Eric; Peroux, Celine; Pichon, Christophe;
Poggianti, Bianca; Richard, Johan; Salmon, Derrick; Seibert, Arnaud;
Shastri, Prajval; Smith, Dan; Sutaria, Firoza; Tao, Charling; Taylor,
Edwar; Tully, Brent; van Waerbeke, Ludovic; Vermeulen, Tom; Walker,
Matthew; Willis, Jon; Willot, Chris; Withington, Kanoa
2019arXiv190404907T Altcode:
(Abridged) The Maunakea Spectroscopic Explorer (MSE) is an end-to-end
science platform for the design, execution and scientific exploitation
of spectroscopic surveys. It will unveil the composition and dynamics
of the faint Universe and impact nearly every field of astrophysics
across all spatial scales, from individual stars to the largest scale
structures in the Universe. Major pillars in the science program for MSE
include (i) the ultimate Gaia follow-up facility for understanding the
chemistry and dynamics of the distant Milky Way, including the outer
disk and faint stellar halo at high spectral resolution (ii) galaxy
formation and evolution at cosmic noon, via the type of revolutionary
surveys that have occurred in the nearby Universe, but now conducted at
the peak of the star formation history of the Universe (iii) derivation
of the mass of the neutrino and insights into inflationary physics
through a cosmological redshift survey that probes a large volume of
the Universe with a high galaxy density. MSE is positioned to become
a critical hub in the emerging international network of front-line
astronomical facilities, with scientific capabilities that naturally
complement and extend the scientific power of Gaia, the Large Synoptic
Survey Telescope, the Square Kilometer Array, Euclid, WFIRST, the 30m
telescopes and many more.
---------------------------------------------------------
Title: On the Connection between Li Depletion and Blue Stragglers
and Possible Implications on the Spite Plateau Meltdown
Authors: Bonifacio, P.; Caffau, E.; Spite, M.; Spite, F.
2019RNAAS...3...64B Altcode: 2019RNAAS...3d..64B
No abstract at ADS
---------------------------------------------------------
Title: Be and O in the ultra metal-poor dwarf 2MASS J18082002-5104378:
the Be-O correlation
Authors: Spite, M.; Bonifacio, P.; Spite, F.; Caffau, E.; Sbordone,
L.; Gallagher, A. J.
2019A&A...624A..44S Altcode: 2019arXiv190211048S
Context. Measurable amounts of Be could have been synthesised
primordially if the Universe were non-homogeneous or in the presence
of late decaying relic particles. <BR /> Aims: We investigate the Be
abundance in the extremely metal-poor star 2MASS J1808-5104 ([Fe/H] =
-3.84) with the aim of constraining inhomogeneities or the presence
of late decaying particles. <BR /> Methods: High resolution, high
signal-to-noise ratio (S/N) UV spectra were acquired at ESO with
the Kueyen 8.2 m telescope and the UVES spectrograph. Abundances were
derived using several model atmospheres and spectral synthesis code. <BR
/> Results: We measured log(Be/H) = -14.3 from a spectrum synthesis of
the region of the Be line. Using a conservative approach, however we
adopted an upper limit two times higher, i.e. log(Be/H) < -14.0. We
measured the O abundance from UV-OH lines and find [O/H] = -3.46
after a 3D correction. <BR /> Conclusions: Our observation reinforces
the existing upper limit on primordial Be. There is no observational
indication for a primordial production of <SUP>9</SUP>Be. This places
strong constraints on the properties of putative relic particles. This
result also supports the hypothesis of a homogeneous Universe, at
the time of nucleosynthesis. Surprisingly, our upper limit of the
Be abundance is well below the Be measurements in stars of similar
[O/H]. This may be evidence that the Be-O relation breaks down in the
early Galaxy, perhaps due to the escape of spallation products from
the gas clouds in which stars such as 2MASS J1808-5104 have formed. <P
/>Based on observations collected at the European Organisation for
Astronomical Research in the Southern Hemisphere under ESO programmes
101.A-0229(A), (PI M.Spite) and 293.D-5036 (PI J. Mélendez). This
research has also made use of Keck Observatory Archive (KOA),
operated by the W. M. Keck Observatory and the NASA Exoplanet Science
Institute (NExScI), under contract with the National Aeronautics and
Space Administration (PI A. Boesgaard).The 3D values of the oxygen
abundance are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/624/A44">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/624/A44</A>
---------------------------------------------------------
Title: 4MOST: Project overview and information for the First Call
for Proposals
Authors: de Jong, R. S.; Agertz, O.; Berbel, A. A.; Aird, J.;
Alexander, D. A.; Amarsi, A.; Anders, F.; Andrae, R.; Ansarinejad,
B.; Ansorge, W.; Antilogus, P.; Anwand-Heerwart, H.; Arentsen, A.;
Arnadottir, A.; Asplund, M.; Auger, M.; Azais, N.; Baade, D.; Baker,
G.; Baker, S.; Balbinot, E.; Baldry, I. K.; Banerji, M.; Barden,
S.; Barklem, P.; Barthélémy-Mazot, E.; Battistini, C.; Bauer, S.;
Bell, C. P. M.; Bellido-Tirado, O.; Bellstedt, S.; Belokurov, V.;
Bensby, T.; Bergemann, M.; Bestenlehner, J. M.; Bielby, R.; Bilicki,
M.; Blake, C.; Bland-Hawthorn, J.; Boeche, C.; Boland, W.; Boller,
T.; Bongard, S.; Bongiorno, A.; Bonifacio, P.; Boudon, D.; Brooks,
D.; Brown, M. J. I.; Brown, R.; Brüggen, M.; Brynnel, J.; Brzeski,
J.; Buchert, T.; Buschkamp, P.; Caffau, E.; Caillier, P.; Carrick,
J.; Casagrande, L.; Case, S.; Casey, A.; Cesarini, I.; Cescutti, G.;
Chapuis, D.; Chiappini, C.; Childress, M.; Christlieb, N.; Church, R.;
Cioni, M. -R. L.; Cluver, M.; Colless, M.; Collett, T.; Comparat, J.;
Cooper, A.; Couch, W.; Courbin, F.; Croom, S.; Croton, D.; Daguisé,
E.; Dalton, G.; Davies, L. J. M.; Davis, T.; de Laverny, P.; Deason,
A.; Dionies, F.; Disseau, K.; Doel, P.; Döscher, D.; Driver, S. P.;
Dwelly, T.; Eckert, D.; Edge, A.; Edvardsson, B.; Youssoufi, D. E.;
Elhaddad, A.; Enke, H.; Erfanianfar, G.; Farrell, T.; Fechner, T.;
Feiz, C.; Feltzing, S.; Ferreras, I.; Feuerstein, D.; Feuillet, D.;
Finoguenov, A.; Ford, D.; Fotopoulou, S.; Fouesneau, M.; Frenk, C.;
Frey, S.; Gaessler, W.; Geier, S.; Gentile Fusillo, N.; Gerhard,
O.; Giannantonio, T.; Giannone, D.; Gibson, B.; Gillingham, P.;
González-Fernández, C.; Gonzalez-Solares, E.; Gottloeber, S.; Gould,
A.; Grebel, E. K.; Gueguen, A.; Guiglion, G.; Haehnelt, M.; Hahn, T.;
Hansen, C. J.; Hartman, H.; Hauptner, K.; Hawkins, K.; Haynes, D.;
Haynes, R.; Heiter, U.; Helmi, A.; Aguayo, C. H.; Hewett, P.; Hinton,
S.; Hobbs, D.; Hoenig, S.; Hofman, D.; Hook, I.; Hopgood, J.; Hopkins,
A.; Hourihane, A.; Howes, L.; Howlett, C.; Huet, T.; Irwin, M.; Iwert,
O.; Jablonka, P.; Jahn, T.; Jahnke, K.; Jarno, A.; Jin, S.; Jofre,
P.; Johl, D.; Jones, D.; Jönsson, H.; Jordan, C.; Karovicova, I.;
Khalatyan, A.; Kelz, A.; Kennicutt, R.; King, D.; Kitaura, F.; Klar,
J.; Klauser, U.; Kneib, J. -P.; Koch, A.; Koposov, S.; Kordopatis, G.;
Korn, A.; Kosmalski, J.; Kotak, R.; Kovalev, M.; Kreckel, K.; Kripak,
Y.; Krumpe, M.; Kuijken, K.; Kunder, A.; Kushniruk, I.; Lam, M. I.;
Lamer, G.; Laurent, F.; Lawrence, J.; Lehmitz, M.; Lemasle, B.; Lewis,
J.; Li, B.; Lidman, C.; Lind, K.; Liske, J.; Lizon, J. -L.; Loveday,
J.; Ludwig, H. -G.; McDermid, R. M.; Maguire, K.; Mainieri, V.; Mali,
S.; Mandel, H.; Mandel, K.; Mannering, L.; Martell, S.; Martinez
Delgado, D.; Matijevic, G.; McGregor, H.; McMahon, R.; McMillan,
P.; Mena, O.; Merloni, A.; Meyer, M. J.; Michel, C.; Micheva, G.;
Migniau, J. -E.; Minchev, I.; Monari, G.; Muller, R.; Murphy, D.;
Muthukrishna, D.; Nandra, K.; Navarro, R.; Ness, M.; Nichani, V.;
Nichol, R.; Nicklas, H.; Niederhofer, F.; Norberg, P.; Obreschkow, D.;
Oliver, S.; Owers, M.; Pai, N.; Pankratow, S.; Parkinson, D.; Paschke,
J.; Paterson, R.; Pecontal, A.; Parry, I.; Phillips, D.; Pillepich,
A.; Pinard, L.; Pirard, J.; Piskunov, N.; Plank, V.; Plüschke, D.;
Pons, E.; Popesso, P.; Power, C.; Pragt, J.; Pramskiy, A.; Pryer,
D.; Quattri, M.; Queiroz, A. B. d. A.; Quirrenbach, A.; Rahurkar,
S.; Raichoor, A.; Ramstedt, S.; Rau, A.; Recio-Blanco, A.; Reiss, R.;
Renaud, F.; Revaz, Y.; Rhode, P.; Richard, J.; Richter, A. D.; Rix,
H. -W.; Robotham, A. S. G.; Roelfsema, R.; Romaniello, M.; Rosario, D.;
Rothmaier, F.; Roukema, B.; Ruchti, G.; Rupprecht, G.; Rybizki, J.;
Ryde, N.; Saar, A.; Sadler, E.; Sahlén, M.; Salvato, M.; Sassolas,
B.; Saunders, W.; Saviauk, A.; Sbordone, L.; Schmidt, T.; Schnurr,
O.; Scholz, R. -D.; Schwope, A.; Seifert, W.; Shanks, T.; Sheinis,
A.; Sivov, T.; Skúladóttir, Á.; Smartt, S.; Smedley, S.; Smith,
G.; Smith, R.; Sorce, J.; Spitler, L.; Starkenburg, E.; Steinmetz,
M.; Stilz, I.; Storm, J.; Sullivan, M.; Sutherland, W.; Swann, E.;
Tamone, A.; Taylor, E. N.; Teillon, J.; Tempel, E.; ter Horst, R.;
Thi, W. -F.; Tolstoy, E.; Trager, S.; Traven, G.; Tremblay, P. -E.;
Tresse, L.; Valentini, M.; van de Weygaert, R.; van den Ancker, M.;
Veljanoski, J.; Venkatesan, S.; Wagner, L.; Wagner, K.; Walcher,
C. J.; Waller, L.; Walton, N.; Wang, L.; Winkler, R.; Wisotzki, L.;
Worley, C. C.; Worseck, G.; Xiang, M.; Xu, W.; Yong, D.; Zhao, C.;
Zheng, J.; Zscheyge, F.; Zucker, D.
2019Msngr.175....3D Altcode: 2019arXiv190302464D
We introduce the 4-metre Multi-Object Spectroscopic Telescope (4MOST),
a new high-multiplex, wide-field spectroscopic survey facility under
development for the four-metre-class Visible and Infrared Survey
Telescope for Astronomy (VISTA) at Paranal. Its key specifications
are: a large field of view (FoV) of 4.2 square degrees and a high
multiplex capability, with 1624 fibres feeding two low-resolution
spectrographs (R = λ/Δλ 6500), and 812 fibres transferring light
to the high-resolution spectrograph (R 20 000). After a description of
the instrument and its expected performance, a short overview is given
of its operational scheme and planned 4MOST Consortium science; these
aspects are covered in more detail in other articles in this edition
of The Messenger. Finally, the processes, schedules, and policies
concerning the selection of ESO Community Surveys are presented,
commencing with a singular opportunity to submit Letters of Intent
for Public Surveys during the first five years of 4MOST operations.
---------------------------------------------------------
Title: 4MOST Consortium Survey 2: The Milky Way Halo High-Resolution
Survey
Authors: Christlieb, N.; Battistini, C.; Bonifacio, P.; Caffau, E.;
Ludwig, H. -G.; Asplund, M.; Barklem, P.; Bergemann, M.; Church, R.;
Feltzing, S.; Ford, D.; Grebel, E. K.; Hansen, C. J.; Helmi, A.;
Kordopatis, G.; Kovalev, M.; Korn, A.; Lind, K.; Quirrenbach, A.;
Rybizki, J.; Skúladóttir, Á.; Starkenburg, E.
2019Msngr.175...26C Altcode: 2019arXiv190302468C
We will study the formation history of the Milky Way, and the earliest
phases of its chemical enrichment, with a sample of more than 1.5
million stars at high galactic latitude. Elemental abundances of up to
20 elements with a precision of better than 0.2 dex will be derived
for these stars. The sample will include members of kinematically
coherent substructures, which we will associate with their possible
birthplaces by means of their abundance signatures and kinematics,
allowing us to test models of galaxy formation. Our target catalogue
is also expected to contain 30 000 stars at a metallicity of less than
one hundredth that of the Sun. This sample will therefore be almost
a factor of 100 larger than currently existing samples of metal-poor
stars for which precise elemental abundances are available (determined
from high-resolution spectroscopy), enabling us to study the early
chemical evolution of the Milky Way in unprecedented detail.
---------------------------------------------------------
Title: Gaia Data Release 2. Variable stars in the colour-absolute
magnitude diagram
Authors: Gaia Collaboration; Eyer, L.; Rimoldini, L.; Audard, M.;
Anderson, R. I.; Nienartowicz, K.; Glass, F.; Marchal, O.; Grenon,
M.; Mowlavi, N.; Holl, B.; Clementini, G.; Aerts, C.; Mazeh, T.;
Evans, D. W.; Szabados, L.; Brown, A. G. A.; Vallenari, A.; Prusti,
T.; de Bruijne, J. H. J.; Babusiaux, C.; Bailer-Jones, C. A. L.;
Biermann, M.; Jansen, F.; Jordi, C.; Klioner, S. A.; Lammers, U.;
Lindegren, L.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich,
S.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; van Leeuwen, F.;
Walton, N. A.; Arenou, F.; Bastian, U.; Cropper, M.; Drimmel, R.;
Katz, D.; Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castañeda,
J.; Chaoul, L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra,
R.; Masana, E.; Messineo, R.; Panuzzo, P.; Portell, J.; Riello, M.;
Seabroke, G. M.; Tanga, P.; Thévenin, F.; Gracia-Abril, G.; Comoretto,
G.; Garcia-Reinaldos, M.; Teyssier, D.; Altmann, M.; Andrae, R.;
Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme, R.; Burgess,
P.; Busso, G.; Carry, B.; Cellino, A.; Clotet, M.; Creevey, O.;
Davidson, M.; De Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant,
C.; Fernández-Hernández, J.; Fouesneau, M.; Frémat, Y.; Galluccio,
L.; García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.;
Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.;
Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Löffler, W.;
Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
Mora, A.; Muinonen, K.; Osinde, J.; Pancino, E.; Pauwels, T.; Petit,
J. -M.; Recio-Blanco, A.; Richards, P. J.; Robin, A. C.; Sarro,
L. M.; Siopis, C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.;
van Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Altavilla,
G.; Álvarez, M. A.; Alvarez, R.; Alves, J.; Andrei, A. H.; Anglada
Varela, E.; Antiche, E.; Antoja, T.; Arcay, B.; Astraatmadja, T. L.;
Bach, N.; Baker, S. G.; Balaguer-Núñez, L.; Balm, P.; Barache,
C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem, P. S.; Barrado,
D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz, S.; Bassilana,
J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.; Bertone, S.;
Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch, T.; Boeche, C.;
Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon, S.; Bourda, G.;
Bragaglia, A.; Bramante, L.; Breddels, M. A.; Bressan, A.; Brouillet,
N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.;
Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere,
R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.;
Carrasco, J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard, A.;
Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza, G.; Costigan, G.;
Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers, J.; Dafonte,
C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; de Laverny, P.;
De Luise, F.; De March, R.; de Martino, D.; de Souza, R.; de Torres,
A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.; Delgado,
H. E.; Diakite, S.; Diener, C.; Distefano, E.; Dolding, C.; Drazinos,
P.; Durán, J.; Edvardsson, B.; Enke, H.; Eriksson, K.; Esquej, P.;
Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Faigler, S.; Falcão,
A. J.; Farràs Casas, M.; Federici, L.; Fedorets, G.; Fernique,
P.; Figueras, F.; Filippi, F.; Findeisen, K.; Fonti, A.; Fraile,
E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti, S.; Garabato, D.;
García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel, A.; Gavras,
P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona, S.;
Giuffrida, G.; Gomes, M.; Granvik, M.; Gueguen, A.; Guerrier, A.;
Guiraud, J.; Gutiérrez-Sánchez, R.; Haigron, R.; Hatzidimitriou,
D.; Hauser, M.; Haywood, M.; Heiter, U.; Helmi, A.; Heu, J.; Hilger,
T.; Hobbs, D.; Hofmann, W.; Holland, G.; Huckle, H. E.; Hypki, A.;
Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.; Jonker, P. G.;
Juhász, Á. L.; Julbe, F.; Karampelas, A.; Kewley, A.; Klar, J.;
Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.; Kontizas, E.;
Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.; Koubsky, P.;
Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; López,
M.; Lorenz, D.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchant,
J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall, D. J.;
Martino, M.; Marton, G.; Mary, N.; Massari, D.; Matijevič, G.;
McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Molina,
D.; Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor, R.; Morbidelli,
R.; Morel, T.; Morgenthaler, S.; Morris, D.; Mulone, A. F.; Muraveva,
T.; Musella, I.; Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane,
W.; Ordénovic, C.; Ordóñez-Blanco, D.; Osborne, P.; Pagani, C.;
Pagano, I.; Pailler, F.; Palacin, H.; Palaversa, L.; Panahi, A.;
Pawlak, M.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum,
G.; Poggio, E.; Poujoulet, E.; Prša, A.; Pulone, L.; Racero, E.;
Ragaini, S.; Rambaux, N.; Ramos-Lerate, M.; Regibo, S.; Reylé, C.;
Riclet, F.; Ripepi, V.; Riva, A.; Rivard, A.; Rixon, G.; Roegiers,
T.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer, F.; Ruiz-Dern,
L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann, J.; Salgado, J.;
Salguero, E.; Sanna, N.; Santana-Ros, T.; Sarasso, M.; Savietto, H.;
Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Ségransan, D.;
Shih, I. -C.; Siltala, L.; Silva, A. F.; Smart, R. L.; Smith, K. W.;
Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.;
Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmüller, H.;
Stephenson, C. A.; Stoev, H.; Suess, F. F.; Surdej, J.; Szegedi-Elek,
E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira,
R.; Terrett, D.; Teyssandier, P.; Thuillot, W.; Titarenko, A.; Torra
Clotet, F.; Turon, C.; Ulla, A.; Utrilla, E.; Uzzi, S.; Vaillant,
M.; Valentini, G.; Valette, V.; van Elteren, A.; Van Hemelryck,
E.; van Leeuwen, M.; Vaschetto, M.; Vecchiato, A.; Veljanoski, J.;
Viala, Y.; Vicente, D.; Vogt, S.; von Essen, C.; Voss, H.; Votruba,
V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Wertz, O.; Wevers, T.;
Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Ziaeepour, H.; Zorec, J.;
Zschocke, S.; Zucker, S.; Zurbach, C.; Zwitter, T.
2019A&A...623A.110G Altcode: 2018arXiv180409382G
Context. The ESA Gaia mission provides a unique time-domain survey
for more than 1.6 billion sources with G ≲ 21 mag. <BR /> Aims:
We showcase stellar variability in the Galactic colour-absolute
magnitude diagram (CaMD). We focus on pulsating, eruptive, and
cataclysmic variables, as well as on stars that exhibit variability
that is due to rotation and eclipses. <BR /> Methods: We describe
the locations of variable star classes, variable object fractions,
and typical variability amplitudes throughout the CaMD and show
how variability-related changes in colour and brightness induce
"motions". To do this, we use 22 months of calibrated photometric,
spectro-photometric, and astrometric Gaia data of stars with a
significant parallax. To ensure that a large variety of variable
star classes populate the CaMD, we crossmatched Gaia sources with
known variable stars. We also used the statistics and variability
detection modules of the Gaia variability pipeline. Corrections for
interstellar extinction are not implemented in this article. <BR />
Results: Gaia enables the first investigation of Galactic variable
star populations in the CaMD on a similar, if not larger, scale as
was previously done in the Magellanic Clouds. Although the observed
colours are not corrected for reddening, distinct regions are visible
in which variable stars occur. We determine variable star fractions
to within the current detection thresholds of Gaia. Finally,
we report the most complete description of variability-induced
motion within the CaMD to date. <BR /> Conclusions: Gaia enables
novel insights into variability phenomena for an unprecedented
number of stars, which will benefit the understanding of stellar
astrophysics. The CaMD of Galactic variable stars provides crucial
information on physical origins of variability in a way that
has previously only been accessible for Galactic star clusters or
external galaxies. Future Gaia data releases will enable significant
improvements over this preview by providing longer time series, more
accurate astrometry, and additional data types (time series BP and
RP spectra, RVS spectra, and radial velocities), all for much larger
samples of stars. <P />A movie associated to Fig. 11 is available at <A
href="https://www.aanda.org/10.1051/0004-6361/201833304/olm">https://www.aanda.org</A>.Data
are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/623/A110">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/623/A110</A>.
---------------------------------------------------------
Title: Systematic investigation of chemical abundances derived using
IR spectra obtained with GIANO
Authors: Caffau, E.; Bonifacio, P.; Oliva, E.; Korotin, S.; Capitanio,
L.; Andrievsky, S.; Collet, R.; Sbordone, L.; Duffau, S.; Sanna, N.;
Tozzi, A.; Origlia, L.; Ryde, N.; Ludwig, H. -G.
2019A&A...622A..68C Altcode: 2018arXiv181205100C
Context. Detailed chemical abundances of Galactic stars are needed in
order to improve our knowledge of the formation and evolution of our
galaxy, the Milky Way. <BR /> Aims: We took advantage of the GIANO
archive spectra to select a sample of Galactic disc stars in order
to derive their chemical inventory and to compare the abundances we
derived from these infrared spectra to the chemical pattern derived
from optical spectra. <BR /> Methods: We analysed high-quality spectra
of 40 stars observed with GIANO. We derived the stellar parameters from
the photometry and the Gaia data-release 2 (DR2) parallax; the chemical
abundances were derived with the code MyGIsFOS. For a subsample of stars
we compared the chemical pattern derived from the GIANO spectra with
the abundances derived from optical spectra. We derived P abundances
for all 40 stars, increasing the number of Galactic stars for which
phosphorus abundance is known. <BR /> Results: We could derive
abundances of 14 elements, 8 of which are also derived from optical
spectra. The comparison of the abundances derived from infrared and
optical spectra is very good. The chemical pattern of these stars is
the one expected for Galactic disc stars and is in agreement with the
results from the literature. <BR /> Conclusions: GIANO is providing
the astronomical community with an extremely useful instrument, able
to produce spectra with high resolution and a wide wavelength range
in the infrared. <P />GIANO programme A31TAC.
---------------------------------------------------------
Title: VizieR Online Data Catalog: 3D-corrected oxygen abundances
for halo stars (Spite+, 2019)
Authors: Spite, M.; Bonifacio, P.; Spite, F.; Caffau, E.; Sbordone,
L.; Gallagher, A. J.
2019yCat..36240044S Altcode:
Oxygen abundance with 3D correction of the stars in the sample of
Boesgaard et al. (2011, Cat. J/ApJ/743/140). <P />(1 data file).
---------------------------------------------------------
Title: VizieR Online Data Catalog: Abundances of very metal-poor
stars in Sagittarius (Hansen+, 2018)
Authors: Hansen, C. J.; El-Souri, M.; Monaco, L.; Villanova, S.;
Bonifacio, P.; Caffau, E.; Sbordone, L.
2019yCat..18550083H Altcode:
Observations were obtained using the high-resolution, cross-dispersed
UV-Visual Echelle Spectrograph (UVES) mounted at the unit 2 telescope
(UT2/Keueyen) of the ESO Very Large Telescope (VLT) in Cerro Paranal,
Chile. Out of 13 stars, 12 were observed with central wavelengths of
390nm and 580nm, for the blue and red arms, respectively. We adopted
a 1.4" wide slit and 2x2 on-chip binning. All the stars were observed
for ~2400-13000s at an airmass between 1.0 and 1.3 in 2009 April and
July. The very metal-poor star Sgr 2300225 was observed using a slightly
different setup in an earlier run (in 2005 August). <P />(3 data files).
---------------------------------------------------------
Title: Calibration of mixing-length parameter α for MLT and FST
models by matching with CO<SUP>5</SUP>BOLD models
Authors: Sonoi, T.; Ludwig, H. -G.; Dupret, M. -A.; Montalbán, J.;
Samadi, R.; Belkacem, K.; Caffau, E.; Goupil, M. -J.
2019A&A...621A..84S Altcode: 2018arXiv181105229S
Context. Space observations by the CoRoT and Kepler missions have
provided a wealth of high-quality seismic data for a large number of
stars from the main sequence to the red giant phases. One main goal of
these missions is to take advantage of the rich spectra of solar-like
oscillations to perform precise determinations of stellar characteristic
parameters. To make the best of such data, we need theoretical stellar
models with a precise near-surface structure since a near-surface
structure of a solar-like star has significant influence on solar-like
oscillation frequencies. The mixing-length parameter is a key factor
to determine the near-surface structure of stellar models. In current
versions of the convection formulations used in stellar evolution
codes, the mixing-length parameter is a free parameter that needs to
be properly specified. <BR /> Aims: We aim at determining appropriate
values of the mixing-length parameter, α, to be used consistently with
the adopted convection formulation when computing stellar evolution
models across the Hertzsprung-Russell diagram. This determination
is based on 3D hydrodynamical simulation models. <BR /> Methods:
We calibrated α values by matching entropy profiles of 1D envelope
models with those of hydrodynamical 3D models of solar-like stars
produced by the CO<SUP>5</SUP>BOLD code. For such calibration, previous
works concentrated on the classical mixing-length theory (MLT). We
also analyzed full spectrum turbulence (FST) models. To construct the
atmosphere in the 1D models, we used the Eddington gray T(τ) relation
and that with the solar-calibrated Hopf-like function. <BR /> Results:
For both MLT and FST models with a mixing length l = αH<SUB>p</SUB>,
calibrated α values increase with increasing surface gravity or
decreasing effective temperature. For the FST models, we carried
out an additional calibration using an α<SUP>*</SUP> value defined
as l = r<SUB>top</SUB> - r + α<SUP>*</SUP>H<SUB>p, top</SUB>, where
α<SUP>*</SUP> is found to increase with surface gravity and effective
temperature. We provide tables of the calibrated α values across
the T<SUB>eff</SUB>-log g plane for solar metallicity. By computing
stellar evolution with varying α based on our 3D α calibration, we
find that the change from solar α to varying α shifts evolutionary
tracks particularly for the FST model. As for the correspondence
to the 3D models, the solar Hopf-like function generally gives a
photospheric-minimum entropy closer to a 3D model than the Eddington
T(τ). The structure below the photosphere depends on the adopted
convection model. However, we cannot obtain a definitive conclusion
about which convection model gives the best correspondence to the 3D
models. This is because each 1D physical quantity is related via an
equation of state (EoS), but it is not the case for the averaged 3D
quantities. Although the FST models with l = r<SUB>top</SUB> - r +
α<SUP>*</SUP>H<SUB>p, top</SUB> are found to give the oscillation
frequencies closest to the solar observed frequencies, their acoustic
cavities are formed with compensatory effects between deviating
density and temperature profiles near the top of the convective
envelope. In future work, an appropriate treatment of the top part of
the 1D convective envelope is necessary, for example, by considering
turbulent pressure and overshooting.
---------------------------------------------------------
Title: TOPoS. V. Abundance ratios in a sample of very metal-poor
turn-off stars
Authors: François, P.; Caffau, E.; Bonifacio, P.; Spite, M.; Spite,
F.; Cayrel, R.; Christlieb, N.; Gallagher, A. J.; Klessen, R.; Koch,
A.; Ludwig, H. -G.; Monaco, L.; Plez, B.; Steffen, M.; Zaggia, S.
2018A&A...620A.187F Altcode: 2018arXiv181100035F
Context. Extremely metal-poor stars are keys to understand the early
evolution of our Galaxy. The ESO large programme TOPoS has been tailored
to analyse a new set of metal-poor turn-off stars, whereas most of
the previously known extremely metal-poor stars are giant stars. <BR
/> Aims: Sixty five turn-off stars (preselected from SDSS spectra)
have been observed with the X-shooter spectrograph at the ESO VLT Unit
Telescope 2, to derive accurate and detailed abundances of magnesium,
silicon, calcium, iron, strontium and barium. <BR /> Methods: We
analysed medium-resolution spectra (R ≃ 10 000) obtained with the
ESO X-shooter spectrograph and computed the abundances of several
α and neutron-capture elements using standard one-dimensional local
thermodynamic equilibrium (1D LTE) model atmospheres. <BR /> Results:
Our results confirms the super-solar [Mg/Fe] and [Ca/Fe] ratios in
metal-poor turn-off stars as observed in metal-poor giant stars. We
found a significant spread of the [α/Fe] ratios with several stars
showing subsolar [Ca/Fe] ratios. We could measure the abundance of
strontium in 12 stars of the sample, leading to abundance ratios
[Sr/Fe] around the Solar value. We detected barium in two stars
of the sample. One of the stars (SDSS J114424-004658) shows both
very high [Ba/Fe] and [Sr/Fe] abundance ratios (>1 dex). <P
/>Based on observations collected at the European Organisation for
Astronomical Research in the Southern Hemisphere under ESO programme ID
189.D-0165. <P />Equivalent widths of the Fe lines are only, and Tables
A.1 and A.2 are also available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/620/A187">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/620/A187</A>
---------------------------------------------------------
Title: The Pristine survey IV: approaching the Galactic metallicity
floor with the discovery of an ultra-metal-poor star
Authors: Starkenburg, Else; Aguado, David S.; Bonifacio, Piercarlo;
Caffau, Elisabetta; Jablonka, Pascale; Lardo, Carmela; Martin,
Nicolas; Sánchez-Janssen, Rubén; Sestito, Federico; Venn, Kim A.;
Youakim, Kris; Allende Prieto, Carlos; Arentsen, Anke; Gentile, Marc;
González Hernández, Jonay I.; Kielty, Collin; Koppelman, Helmer H.;
Longeard, Nicolas; Tolstoy, Eline; Carlberg, Raymond G.; Côté,
Patrick; Fouesneau, Morgan; Hill, Vanessa; McConnachie, Alan W.;
Navarro, Julio F.
2018MNRAS.481.3838S Altcode: 2018arXiv180704292S; 2018MNRAS.tmp.2167S
The early Universe presented a star formation environment that
was almost devoid of heavy elements. The lowest metallicity stars
thus provide a unique window into the earliest Galactic stages,
but are exceedingly rare and difficult to find. Here, we present the
discovery of an ultra-metal-poor star, Pristine_221.8781+9.7844, using
narrow-band Ca H&K photometry from the Pristine survey. Follow-up
medium- and high-resolution spectroscopy confirms the ultra-metal-poor
nature of Pristine_221.8781+9.7844 ([Fe/H] = -4.66 ± 0.13 in 1D LTE)
with an enhancement of 0.3-0.4 dex in α-elements relative to Fe,
and an unusually low carbon abundance. We derive an upper limit of
A(C) = 5.6, well below typical A(C) values for such ultra-metal-poor
stars. This makes Pristine_221.8781+9.7844 one of the most metal-poor
stars; in fact, it is very similar to the most metal-poor star known
(SDSS J102915+172927). The existence of a class of ultra-metal-poor
stars with low(er) carbon abundances suggest that there must have
been several formation channels in the early Universe through which
long-lived, low-mass stars were formed.
---------------------------------------------------------
Title: Influence of metallicity on the near-surface effect on
oscillation frequencies
Authors: Manchon, L.; Belkacem, K.; Samadi, R.; Sonoi, T.; Marques,
J. P. C.; Ludwig, H. -G.; Caffau, E.
2018A&A...620A.107M Altcode: 2018arXiv180908904M
Context. The CoRoT and Kepler missions have provided high-quality
measurements of the frequency spectra of solar-like pulsators,
enabling us to probe stellar interiors with a very high degree of
accuracy by comparing the observed and modelled frequencies. However,
the frequencies computed with 1D models suffer from systematic
errors related to the poor modelling of the uppermost layers of
stars. These biases are what is commonly named the near-surface
effect. The dominant effect is thought to be related to the turbulent
pressure that modifies the hydrostatic equilibrium and thus the
frequencies. This has already been investigated using grids of 3D
hydrodynamical simulations, which also were used to constrain the
parameters of the empirical correction models. However, the effect
of metallicity has not been considered so far. <BR /> Aims: We aim to
study the impact of metallicity on the surface effect, investigating
its influence across the Hertzsprung-Russell diagram, and providing
a method for accounting for it when using the empirical correction
models. <BR /> Methods: We computed a grid of patched 1D stellar
models with the stellar evolution code CESTAM in which poorly modelled
surface layers have been replaced by averaged stratification computed
with the 3D hydrodynamical code CO<SUP>5</SUP>BOLD. It allowed us to
investigate the dependence of both the surface effect and the empirical
correction functions on the metallicity. <BR /> Results: We found
that metallicity has a strong impact on the surface effect: keeping
T<SUB>eff</SUB> and log g constant, the frequency residuals can vary by
up to a factor of two (for instance from [Fe/H] = + 0.0 to [Fe/H] = +
0.5). Therefore, the influence of metallicity cannot be neglected. We
found that the correct way of accounting for it is to consider the
surface Rosseland mean opacity. It allowed us to give a physically
grounded justification as well as a scaling relation for the frequency
differences at ν<SUB>max</SUB> as a function of T<SUB>eff</SUB>, log g
and κ. Finally, we provide prescriptions for the fitting parameters of
the most commonly used correction functions. <BR /> Conclusions: We show
that the impact of metallicity through the Rosseland mean opacity must
be taken into account when studying and correcting the surface effect.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Very metal-poor turn-off stars
abundances (Francois+, 2018)
Authors: Francois, P.; Caffau, E.; Bonifacio, P.; Spite, M.; Spite,
F.; Cayrel, R.; Christlieb, N.; Gallagher, A.; Klessen, R.; Koch,
A.; Ludwig, H. -G.; Monaco, L.; Plez, B.; Steffen, M.; Zaggia, S.
2018yCat..36200187F Altcode:
Sixty five turn-off stars (preselected from SDSS spectra) have been
observed with the X-Shooter spectrograph at the ESO VLT Unit Telescope
2, to derive accurate and detailed abundances of magnesium, silicon,
calcium, iron, strontium and barium. We analysed medium-resolution
spectra (R~10000) obtained with the ESO X-Shooter spectrograph and
computed the abundances of several alpha and neutron-capture elements
using standard one-dimensional local thermodynamic equilibrium (1D LTE)
model atmospheres. <P />(3 data files).
---------------------------------------------------------
Title: A chemical study of M67 candidate blue stragglers and evolved
blue stragglers observed with APOGEE DR14
Authors: Bertelli Motta, Clio; Pasquali, Anna; Caffau, Elisabetta;
Grebel, Eva K.
2018MNRAS.480.4314B Altcode: 2018MNRAS.tmp.2080M; 2018arXiv180804601B
Within the variety of objects populating stellar clusters, blue
straggler stars (BSSs) are among the most puzzling ones. BSSs are
commonly found in globular clusters, but they are also known to
populate open clusters of the Milky Way. Two main theoretical scenarios
(collisions and mass transfer) have been suggested to explain their
formation, although finding observational evidence in support of either
scenario represents a challenging task. Among the APOGEE observations
of the old open cluster M67, we found eight BSS candidates known from
the literature and two known evolved BSSs. We carried out a chemical
analysis of three BSS candidates and of the two evolved BSSs out of the
sample and found that the BSS candidates have surface abundances similar
to those of stars on the main-sequence turn-off of M67. Especially the
absence of any anomaly in their carbon abundances seems to support a
collisional formation scenario for these stars. Furthermore, we note
that the abundances of the evolved BSSs S1040 and S1237 are consistent
with the abundances of the red clump stars of M67. In particular,
they show a depletion in carbon by ∼0.25 dex, which could be either
interpreted as the signature of mass transfer or as the product of
stellar evolutionary processes. Finally, we summarize the properties
of the individual BSSs observed by APOGEE, as derived from their APOGEE
spectra and/or from information available in the literature.
---------------------------------------------------------
Title: Chemical analysis of very metal-poor turn-off stars from
SDSS-DR12
Authors: François, P.; Caffau, E.; Wanajo, S.; Aguado, D.; Spite,
M.; Aoki, M.; Aoki, W.; Bonifacio, P.; Gallagher, A. J.; Salvadori,
S.; Spite, F.
2018A&A...619A..10F Altcode: 2018arXiv180809918F
Context. The most metal-poor stars are the relics of the early chemical
evolution of the Galaxy. Their chemical composition is an important tool
to constrain the nucleosynthesis in the first generation of stars. The
aim is to observe a sample of extremely metal-poor star (EMP stars)
candidates selected from the Sloan Digital Sky Survey Data Release 12
(SDSS DR12) and determine their chemical composition. <BR /> Aims:
We obtain medium resolution spectra of a sample of six stars using the
X-shooter spectrograph at the Very Large Telescope (VLT) and we used
ATLAS models to compute the abundances. <BR /> Methods: Five stars
of the sample have a metallicity [Fe/H] between -2.5 dex and -3.2
dex. We confirm the recent discovery of SDSS J002314.00+030758.0 as a
star with an extremely low [Fe/H] ratio. Assuming the α-enhancement
[Ca/Fe] = +0.4 dex, we obtain [Fe/H] = -6.1 dex. <BR /> Results:
We could also determine its magnesium abundance and found that this
star exhibits a very high ratio [Mg/Fe]≤ +3.60 dex assuming [Fe/H]
= -6.13 dex. We determined the carbon abundance and found A(C) = 6.4
dex. From this carbon abundance, this stars belongs to the lower band
of the A(C)-[Fe/H] diagram. <P />Based on observations collected at
the European Organisation for Astronomical Research in the Southern
Hemisphere under ESO programme ID 099.D-0576(A).
---------------------------------------------------------
Title: 3D non-LTE corrections for Li abundance and
<SUP>6</SUP>Li/<SUP>7</SUP>Li isotopic ratio in solar-type
stars. I. Application to HD 207129 and HD 95456
Authors: Harutyunyan, G.; Steffen, M.; Mott, A.; Caffau, E.; Israelian,
G.; González Hernández, J. I.; Strassmeier, K. G.
2018A&A...618A..16H Altcode: 2018arXiv180704089H
Context. Convective motions in solar-type stellar atmospheres
induce Doppler shifts that affect the strengths and shapes of
spectral absorption lines and create slightly asymmetric line
profiles. One-dimensional (1D) local thermodynamic equilibrium
(LTE) studies of elemental abundances are not able to reproduce this
phenomenon, which becomes particularly important when modeling the
impact of isotopic fine structure, like the subtle depression created by
the <SUP>6</SUP>Li isotope on the red wing of the Li I resonance doublet
line. <BR /> Aims: The purpose of this work is to provide corrections
for the lithium abundance, A(Li), and the <SUP>6</SUP>Li/<SUP>7</SUP>Li
isotopic ratio that can easily be applied to correct 1D LTE lithium
abundances in G and F dwarf stars of approximately solar mass and
metallicity for three-dimensional (3D) and non-LTE (NLTE) effects. <BR
/> Methods: The corrections for A(Li) and <SUP>6</SUP>Li/<SUP>7</SUP>Li
are computed using grids of 3D NLTE and 1D LTE synthetic lithium
line profiles, generated from 3D hydro-dynamical CO<SUP>5</SUP>BOLD
and 1D hydrostatic model atmospheres, respectively. For comparative
purposes, all calculations are performed for three different line
lists representing the Li I λ670.8 nm spectral region. The 3D NLTE
corrections are then approximated by analytical expressions as a
function of the stellar parameters (T<SUB>eff</SUB>, log ℊ, [Fe/H],
ν sin i, A(Li), <SUP>6</SUP>Li/<SUP>7</SUP>Li). These are applied to
adjust the 1D LTE isotopic lithium abundances in two solar-type stars,
<ASTROBJ>HD 207129</ASTROBJ> and <ASTROBJ>HD 95456</ASTROBJ>, for
which high-quality HARPS observations are available. <BR /> Results:
The derived 3D NLTE corrections range between -0.01 and +0.11 dex for
A(Li), and between -4.9 and -0.4% for <SUP>6</SUP>Li/<SUP>7</SUP>Li,
depending on the adopted stellar parameters. We confirm that the
inferred <SUP>6</SUP>Li abundance depends critically on the strength of
the Si I 670.8025 nm line. Our findings show a general consistency with
recent works on lithium abundance corrections. After the application of
such corrections, we do not find a significant amount of <SUP>6</SUP>Li
in any of the two target stars. <BR /> Conclusions: In the case of
<SUP>6</SUP>Li/<SUP>7</SUP>Li, our corrections are always negative,
showing that 1D LTE analysis can significantly overestimate the
presence of <SUP>6</SUP>Li (up to 4.9% points) in the atmospheres
of solar-like dwarf stars. These results emphasize the importance
of reliable 3D model atmospheres combined with NLTE line formation
for deriving precise isotopic lithium abundances. Although 3D NLTE
spectral synthesis implies an extensive computational effort,
the results can be made accessible with parametric tools like
the ones presented in this work. <P />The table with the 3D NLTE
corrections is only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/618/A16">http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/618/A16</A>
---------------------------------------------------------
Title: Calibration of the mixing length of the MLT and FST models
using 3D hydrodynamical models
Authors: Sonoi, T.; Ludwig, H. -G.; Dupret, M. -A.; Montalban, J.;
Belkacem, K.; Caffau, E.
2018phos.confE..27S Altcode:
Rich spectra of solar-like oscillations obtained with space observations
are expected to enable us to perform precise determinations of stellar
properties. To make the best of the spectra, we need theoretical
stellar models with precise near-surface structure, since the
near-surface structure has significant influence on solar-like
oscillation frequencies. The mixing-length parameter, α, is a key
factor to determine the near-surface structure. We aimed at determining
appropriate α values based on 3D radiation-coupled hydrodynamical
models produced by the CO^5BOLD code. For such calibration, previous
works concentrated on the classical mixing-length theory (MLT). Here
we also analyzed the full spectrum turbulence (FST) models. The
trends of the calibrated α values in the T<SUB>eff</SUB>-g plane is
found to be similar to those of previous calibrations with the other
grids of RHD models. A T(τ) relation based on the so-called VAL-C
solar-atmosphere model is found to give better correspondence to
the photospheric-minimum entropy in the 3D model than the Eddington
T(τ) relation. Although the structure below the photosphere depends
on convection models, not a single convection model gives the best
correspondence to the 3D model since physical quantities in the 3D
models are not necessarily related via an equation of states unlike
those in the 1D models. Although the FST model with a form of a mixing
length (l=r<SUB>top</SUB>-r+α<SUP>*</SUP>H<SUB>p,{top}</SUB>) is found
to give solar-oscillation frequencies apparently closest to the observed
ones, the acoustic cavity of this model is formed with compensatory
effects between deviating density and temperature profiles just below
the top of the convective envelope. In future work, a more sophisticated
treatment of the top part of the 1D convective envelope is necessary.
---------------------------------------------------------
Title: A physically-grounded relation between the metallicity and
the surface term affecting stellar oscillation frequencies
Authors: Manchon, Louis; Belkacem, Kevin; Samadi, Reza; Sonoi,
Takafumi; Marques, J. P. C.; Ludwig, Hans-Gunter; Caffau, E.
2018phos.confE..36M Altcode:
The CoRoT and Kepler missions have provided high-quality measurements
of the frequency spectra of solar-like pulsators, enabling us to probe
stellar interiors with a very high degree of accuracy by comparing the
observed and modeled frequencies. However, the frequencies computed with
1D models suffer from systematic errors related to the poor modeling of
the uppermost layers of stars. These biases are what is commonly named
the near surface effect. The dominant effect is thought to be related
to the turbulent pressure that modifies the hydrostatic equilibrium and
thus the frequencies. This has already been investigated using grids
of 3D hydrodynamical simulations, however, the effect of metallicity
has not been considered so far. We aim at studying the impact of
metallicity on the surface effect, investigating its influence across
the Hertzsprung–Russell diagram, and providing a relation between
the frequency differences and global parameters. We computed a grid
of 29 patched 1D stellar models with the stellar evolution code
CESTAM in which poorly modeled surface layers have been replaced by
averaged stratification computed with the 3D hydrodynamical code CO 5
BOLD. It allowed us to study the dependence of the surface effect on
the metallicity. We found that a correct way of accounting for it is
to consider the surface Rosseland mean opacity. It allowed us to give a
physically-grounded justification as well as a scaling relation for the
frequency differences at ν max as a function of T eff , log g and κ.
---------------------------------------------------------
Title: Abundance of zinc in the red giants of Galactic globular
cluster 47 Tucanae
Authors: Černiauskas, A.; Kučinskas, A.; Klevas, J.; Bonifacio,
P.; Ludwig, H. -G.; Caffau, E.; Steffen, M.
2018A&A...616A.142C Altcode: 2018arXiv180603132C
<BR /> Aims: We investigate possible relations between the abundances
of zinc and the light elements sodium, magnesium, and potassium
in the atmospheres of red giant branch (RGB) stars of the Galactic
globular cluster 47 Tuc and study connections between the chemical
composition and dynamical properties of the cluster RGB stars. <BR
/> Methods: The abundance of zinc was determined in 27 RGB stars
of 47 Tuc using 1D local thermal equilibrium (LTE) synthetic line
profile fitting to the high-resolution 2dF/HERMES spectra obtained
with the Anglo-Australian Telescope (AAT). Synthetic spectra used
in the fitting procedure were computed with the SYNTHE code and
1D ATLAS9 stellar model atmospheres. <BR /> Results: The average
1D LTE zinc-to-iron abundance ratio and its RMS variations due to
star-to-star abundance spread determined in the sample of 27 RGB stars
is <[Zn/Fe]><SUP>1D LTE</SUP> = 0.11 ± 0.09. We did not detect
any statistically significant relations between the abundances of
zinc and those of light elements. Neither did we find any significant
correlation or anticorrelation between the zinc abundance in individual
stars and their projected distance from the cluster center. Finally,
no statistically significant relation between the absolute radial
velocities of individual stars and the abundance of zinc in their
atmospheres was detected. The obtained average [Zn/Fe]<SUP>1DLTE</SUP>
ratio agrees well with those determined in this cluster in earlier
studies and nearly coincides with that of Galactic field stars at this
metallicity. All these results suggest that nucleosynthesis of zinc
and light elements proceeded in separate, unrelated pathways in 47 Tuc.
---------------------------------------------------------
Title: A CEMP-no star in the ultra-faint dwarf galaxy Pisces II
Authors: Spite, M.; Spite, F.; François, P.; Bonifacio, P.; Caffau,
E.; Salvadori, S.
2018A&A...617A..56S Altcode: 2018arXiv180701542S
<BR /> Aims: A probable carbon enhanced metal-poor (CEMP) star, Pisces
II 10694, was discovered recently in the ultra-faint (UFD) galaxy Pisces
II. This galaxy is supposed to be very old, suspected to include dark
matter, and likely formed the bulk of its stars before the reionisation
of the Universe. <BR /> Methods: New abundances have been obtained from
observations of Pisces II 10694 at the Kueyen ESO VLT telescope, using
the high-efficiency spectrograph: X-shooter. <BR /> Results: We found
that Pisces II 10694 is a CEMP-no star with [Fe/H] = -2.60 dex. Careful
measurements of the CH and C<SUB>2</SUB> bands confirm the enhancement
of the C abundance ([C/Fe] = +1.23). This cool giant has very probably
undergone extra mixing and thus its original C abundance could be even
higher. Nitrogen, O, Na, and Mg are also strongly enhanced, but from
Ca to Ni the ratios [X/Fe] are similar to those observed in classical
very metal-poor stars. With its low Ba abundance ([Ba/Fe] = -1.10 dex)
Pisces II 10694 is a CEMP-no star. No variation in the radial velocity
could be detected between 2015 and 2017. The pattern of the elements has
a shape similar to the pattern found in galactic CEMP-no stars like CS
22949-037 ([Fe/H] = -4.0) or SDSS J1349+1407 ([Fe/H] = -3.6). <BR />
Conclusions: The existence of a CEMP-no star in the UFD galaxy Pisc
II suggests that this small galaxy likely hosted zero-metallicity
stars. This is consistent with theoretical predictions of cosmological
models supporting the idea that UFD galaxies are the living fossils of
the first star-forming systems. <P />Based on observations collected
at the European Organisation for Astronomical Research in the Southern
Hemisphere under ESO programme 099.B-0062(A).
---------------------------------------------------------
Title: Gaia Data Release 2. Observations of solar system objects
Authors: Gaia Collaboration; Spoto, F.; Tanga, P.; Mignard, F.;
Berthier, J.; Carry, B.; Cellino, A.; Dell'Oro, A.; Hestroffer, D.;
Muinonen, K.; Pauwels, T.; Petit, J. -M.; David, P.; De Angeli, F.;
Delbo, M.; Frézouls, B.; Galluccio, L.; Granvik, M.; Guiraud, J.;
Hernández, J.; Ordénovic, C.; Portell, J.; Poujoulet, E.; Thuillot,
W.; Walmsley, G.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de
Bruijne, J. H. J.; Babusiaux, C.; Bailer-Jones, C. A. L.; Biermann,
M.; Evans, D. W.; Eyer, L.; Jansen, F.; Jordi, C.; Klioner, S. A.;
Lammers, U.; Lindegren, L.; Luri, X.; Panem, C.; Pourbaix, D.; Randich,
S.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; van Leeuwen, F.;
Walton, N. A.; Arenou, F.; Bastian, U.; Cropper, M.; Drimmel, R.;
Katz, D.; Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castañeda, J.;
Chaoul, L.; Cheek, N.; Fabricius, C.; Guerra, R.; Holl, B.; Masana,
E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Panuzzo, P.; Riello,
M.; Seabroke, G. M.; Thévenin, F.; Gracia-Abril, G.; Comoretto,
G.; Garcia-Reinaldos, M.; Teyssier, D.; Altmann, M.; Andrae, R.;
Audard, M.; Bellas-Velidis, I.; Benson, K.; Blomme, R.; Burgess, P.;
Busso, G.; Clementini, G.; Clotet, M.; Creevey, O.; Davidson, M.; De
Ridder, J.; Delchambre, L.; Ducourant, C.; Fernández-Hernández, J.;
Fouesneau, M.; Frémat, Y.; García-Torres, M.; González-Núñez,
J.; González-Vidal, J. J.; Gosset, E.; Guy, L. P.; Halbwachs,
J. -L.; Hambly, N. C.; Harrison, D. L.; Hodgkin, S. T.; Hutton,
A.; Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn,
A. J.; Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Lö, W.;
Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
Mora, A.; Osinde, J.; Pancino, E.; Recio-Blanco, A.; Richards, P. J.;
Rimoldini, L.; Robin, A. C.; Sarro, L. M.; Siopis, C.; Smith, M.;
Sozzetti, A.; Süveges, M.; Torra, J.; van Reeven, W.; Abbas, U.;
Abreu Aramburu, A.; Accart, S.; Aerts, C.; Altavilla, G.; Álvarez,
M. A.; Alvarez, R.; Alves, J.; Anderson, R. I.; Andrei, A. H.; Anglada
Varela, E.; Antiche, E.; Antoja, T.; Arcay, B.; Astraatmadja, T. L.;
Bach, N.; Baker, S. G.; Balaguer-Núñez, L.; Balm, P.; Barache,
C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem, P. S.; Barrado,
D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz, L.; Bassilana,
J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.; Bertone, S.;
Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch, T.; Boeche, C.;
Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon, S.; Bourda, G.;
Bragaglia, A.; Bramante, L.; Breddels, M. A.; Bressan, A.; Brouillet,
N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.;
Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere,
R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.;
Carrasco, J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard,
A.; Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza, G.; Costigan,
G.; Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers, J.;
Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, M.; de Laverny, P.;
De Luise, F.; De March, R.; de Souza, R.; de Torres, A.; Debosscher,
J.; del Pozo, E.; Delgado, A.; Delgado, H. E.; Diakite, S.; Diener,
C.; Distefano, E.; Dolding, C.; Drazinos, P.; Durán, J.; Edvardsson,
B.; Enke, H.; Eriksson, K.; Esquej, P.; Eynard Bontemps, G.; Fabre,
C.; Fabrizio, M.; Faigler, S.; Falcão, A. J.; Farràs Casas, M.;
Federici, L.; Fedorets, G.; Fernique, P.; Figueras, F.; Filippi, F.;
Findeisen, K.; Fonti, A.; Fraile, E.; Fraser, M.; Gai, M.; Galleti, S.;
Garabato, D.; García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel,
A.; Gavras, P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore, G.;
Girona, S.; Giuffrida, G.; Glass, F.; Gomes, M.; Gueguen, A.; Guerrier,
A.; Gutié, R.; Haigron, R.; Hatzidimitriou, D.; Hauser, M.; Haywood,
M.; Heiter, U.; Helmi, A.; Heu, J.; Hilger, T.; Hobbs, D.; Hofmann,
W.; Holland, G.; Huckle, H. E.; Hypki, A.; Icardi, V.; Janßen, K.;
Jevardat de Fombelle, G.; Jonker, P. G.; Juhász, Á. L.; Julbe,
F.; Karampelas, A.; Kewley, A.; Klar, J.; Kochoska, A.; Kohley, R.;
Kolenberg, K.; Kontizas, M.; Kontizas, E.; Koposov, S. E.; Kordopatis,
G.; Kostrzewa-Rutkowska, Z.; Koubsky, P.; Lambert, S.; Lanza, A. F.;
Lasne, Y.; Lavigne, J. -B.; Le Fustec, Y.; Le Poncin-Lafitte, C.;
Lebreton, Y.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Lenhardt,
H.; Leroux, F.; Liao, S.; Licata, E.; Lindstrøm, H. E. P.; Lister,
T. A.; Livanou, E.; Lobel, A.; López, M.; Managau, S.; Mann, R. G.;
Mantelet, G.; Marchal, O.; Marchant, J. M.; Marconi, M.; Marinoni,
S.; Marschalkó, G.; Marshall, D. J.; Martino, M.; Marton, G.; Mary,
N.; Massari, D.; Matijevič, G.; Mazeh, T.; McMillan, P. J.; Messina,
S.; Michalik, D.; Millar, N. R.; Molina, D.; Molinaro, R.; Molnár,
L.; Montegriffo, P.; Mor, R.; Morbidelli, R.; Morel, T.; Morris, D.;
Mulone, A. F.; Muraveva, T.; Musella, I.; Nelemans, G.; Nicastro, L.;
Noval, L.; O'Mullane, W.; Ordóñez-Blanco, D.; Osborne, P.; Pagani,
C.; Pagano, I.; Pailler, F.; Palacin, H.; Palaversa, L.; Panahi, A.;
Pawlak, M.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.;
Poggio, E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.; Rambaux,
N.; Ramos-Lerate, M.; Regibo, S.; Reylé, C.; Riclet, F.; Ripepi,
V.; Riva, A.; Rivard, A.; Rixon, G.; Roegiers, T.; Roelens, M.;
Romero-Gómez, M.; Rowell, N.; Royer, F.; Ruiz-Dern, L.; Sadowski,
G.; Sagristà Sellés, T.; Sahlmann, J.; Salgado, J.; Salguero, E.;
Sanna, N.; Santana-Ros, T.; Sarasso, M.; Savietto, H.; Schultheis, M.;
Sciacca, E.; Segol, M.; Segovia, J. C.; Ségransan, D.; Shih, I. -C.;
Siltala, L.; Silva, A. F.; Smart, R. L.; Smith, K. W.; Solano, E.;
Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.; Spagna, A.;
Stampa, U.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.;
Stoev, H.; Suess, F. F.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.;
Tapiador, D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.;
Terrett, D.; Teyssandier, P.; Titarenko, A.; Torra Clotet, F.; Turon,
C.; Ulla, A.; Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini, G.;
Valette, V.; van Elteren, A.; Van Hemelryck, E.; van Leeuwen, M.;
Vaschetto, M.; Vecchiato, A.; Veljanoski, J.; Viala, Y.; Vicente,
D.; Vogt, S.; von Essen, C.; Voss, H.; Votruba, V.; Voutsinas, S.;
Weiler, M.; Wertz, O.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.;
Žerjal, M.; Ziaeepour, H.; Zorec, J.; Zschocke, S.; Zucker, S.;
Zurbach, C.; Zwitter, T.
2018A&A...616A..13G Altcode: 2018arXiv180409379G
Context. The Gaia spacecraft of the European Space Agency (ESA)
has been securing observations of solar system objects (SSOs) since
the beginning of its operations. Data Release 2 (DR2) contains the
observations of a selected sample of 14,099 SSOs. These asteroids have
been already identified and have been numbered by the Minor Planet
Center repository. Positions are provided for each Gaia observation at
CCD level. As additional information, complementary to astrometry, the
apparent brightness of SSOs in the unfiltered G band is also provided
for selected observations. <BR /> Aims: We explain the processing of SSO
data, and describe the criteria we used to select the sample published
in Gaia DR2. We then explore the data set to assess its quality. <BR />
Methods: To exploit the main data product for the solar system in Gaia
DR2, which is the epoch astrometry of asteroids, it is necessary to take
into account the unusual properties of the uncertainty, as the position
information is nearly one-dimensional. When this aspect is handled
appropriately, an orbit fit can be obtained with post-fit residuals
that are overall consistent with the a-priori error model that was used
to define individual values of the astrometric uncertainty. The role
of both random and systematic errors is described. The distribution
of residuals allowed us to identify possible contaminants in the
data set (such as stars). Photometry in the G band was compared
to computed values from reference asteroid shapes and to the flux
registered at the corresponding epochs by the red and blue photometers
(RP and BP). <BR /> Results: The overall astrometric performance is
close to the expectations, with an optimal range of brightness G 12 -
17. In this range, the typical transit-level accuracy is well below
1 mas. For fainter asteroids, the growing photon noise deteriorates
the performance. Asteroids brighter than G 12 are affected by a lower
performance of the processing of their signals. The dramatic improvement
brought by Gaia DR2 astrometry of SSOs is demonstrated by comparisons
to the archive data and by preliminary tests on the detection of subtle
non-gravitational effects.
---------------------------------------------------------
Title: Carbon-enhanced metal-poor 3D model atmospheres
Authors: Steffen, M.; Gallagher, A. J.; Caffau, E.; Bonifacio, P.;
Ludwig, H. -G.
2018IAUS..334..364S Altcode: 2017arXiv170805686S
We present our latest 3D model atmospheres for carbon-enhanced
metal-poor (CEMP) stars computed with the CO5BOLD code. The stellar
parameters are representative of hot turn-off objects (T<SUB>eff</SUB>
~ 6250 K, log g = 4.0, [Fe/H]=-3). The main purpose of these models
is to investigate the role of 3D effects on synthetic spectra of the
CH G-band (4140-4400 Å), the CN BX-band (3870-3890 Å), and several
UV OH transitions (3122-3128 Å). By comparison with the synthetic
spectra from standard 1D model atmospheres (assuming local thermodynamic
equilibrium, LTE), we derive 3D abundance corrections for carbon and
oxygen of up to -0.5 and -0.7 dex, respectively.
---------------------------------------------------------
Title: Gaia Data Release 2. The celestial reference frame (Gaia-CRF2)
Authors: Gaia Collaboration; Mignard, F.; Klioner, S. A.; Lindegren,
L.; Hernández, J.; Bastian, U.; Bombrun, A.; Hobbs, D.; Lammers, U.;
Michalik, D.; Ramos-Lerate, M.; Biermann, M.; Fernández-Hernández,
J.; Geyer, R.; Hilger, T.; Siddiqui, H. I.; Steidelmüller, H.;
Babusiaux, C.; Barache, C.; Lambert, S.; Andrei, A. H.; Bourda, G.;
Charlot, P.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne,
J. H. J.; Bailer-Jones, C. A. L.; Evans, D. W.; Eyer, L.; Jansen, F.;
Jordi, C.; Luri, X.; Panem, C.; Pourbaix, D.; Randich, S.; Sartoretti,
P.; Soubiran, C.; van Leeuwen, F.; Walton, N. A.; Arenou, F.; Cropper,
M.; Drimmel, R.; Katz, D.; Lattanzi, M. G.; Bakker, J.; Cacciari,
C.; Castañeda, J.; Chaoul, L.; Cheek, N.; De Angeli, F.; Fabricius,
C.; Guerra, R.; Holl, B.; Masana, E.; Messineo, R.; Mowlavi, N.;
Nienartowicz, K.; Panuzzo, P.; Portell, J.; Riello, M.; Seabroke,
G. M.; Tanga, P.; Thévenin, F.; Gracia-Abril, G.; Comoretto,
G.; Garcia-Reinaldos, M.; Teyssier, D.; Altmann, M.; Andrae, R.;
Audard, M.; Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme,
R.; Burgess, P.; Busso, G.; Carry, B.; Cellino, A.; Clementini, G.;
Clotet, M.; Creevey, O.; Davidson, M.; De Ridder, J.; Delchambre, L.;
Dell'Oro, A.; Ducourant, C.; Fouesneau, M.; Frémat, Y.; Galluccio,
L.; García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
D. L.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.; Jasniewicz, G.;
Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.; Krone-Martins, A.;
Lanzafame, A. C.; Lebzelter, T.; Löffler, W.; Manteiga, M.; Marrese,
P. M.; Martín-Fleitas, J. M.; Moitinho, A.; Mora, A.; Muinonen, K.;
Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J. -M.; Recio-Blanco, A.;
Richards, P. J.; Rimoldini, L.; Robin, A. C.; Sarro, L. M.; Siopis,
C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.; van Reeven,
W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.; Altavilla,
G.; Álvarez, M. A.; Alvarez, R.; Alves, J.; Anderson, R. I.; Anglada
Varela, E.; Antiche, E.; Antoja, T.; Arcay, B.; Astraatmadja, T. L.;
Bach, N.; Baker, S. G.; Balaguer-Núñez, L.; Balm, P.; Barata, C.;
Barbato, D.; Barblan, F.; Barklem, P. S.; Barrado, D.; Barros, M.;
Barstow, M. A.; Bartholomé Muñoz, L.; Bassilana, J. -L.; Becciani,
U.; Bellazzini, M.; Berihuete, A.; Bertone, S.; Bianchi, L.; Bienaymé,
O.; Blanco-Cuaresma, S.; Boch, T.; Boeche, C.; Borrachero, R.;
Bossini, D.; Bouquillon, S.; Bragaglia, A.; Bramante, L.; Breddels,
M. A.; Bressan, A.; Brouillet, N.; Brüsemeister, T.; Brugaletta, E.;
Bucciarelli, B.; Burlacu, A.; Busonero, D.; Butkevich, A. G.; Buzzi,
R.; Caffau, E.; Cancelliere, R.; Cannizzaro, G.; Cantat-Gaudin,
T.; Carballo, R.; Carlucci, T.; Carrasco, J. M.; Casamiquela, L.;
Castellani, M.; Castro-Ginard, A.; Chemin, L.; Chiavassa, A.; Cocozza,
G.; Costigan, G.; Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.;
Cuypers, J.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.;
David, M.; de Laverny, P.; De Luise, F.; De March, R.; de Souza, R.;
de Torres, A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.;
Delgado, H. E.; Diakite, S.; Diener, C.; Distefano, E.; Dolding, C.;
Drazinos, P.; Durán, J.; Edvardsson, B.; Enke, H.; Eriksson, K.;
Esquej, P.; Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Faigler,
S.; Falcão, A. J.; Farràs Casas, M.; Federici, L.; Fedorets, G.;
Fernique, P.; Figueras, F.; Filippi, F.; Findeisen, K.; Fonti, A.;
Fraile, E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti, S.; Garabato,
D.; García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel, A.; Gavras,
P.; Gerssen, J.; Giacobbe, P.; Gilmore, G.; Girona, S.; Giuffrida, G.;
Glass, F.; Gomes, M.; Granvik, M.; Gueguen, A.; Guerrier, A.; Guiraud,
J.; Gutié, R.; Haigron, R.; Hatzidimitriou, D.; Hauser, M.; Haywood,
M.; Heiter, U.; Helmi, A.; Heu, J.; Hofmann, W.; Holland, G.; Huckle,
H. E.; Hypki, A.; Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.;
Jonker, P. G.; Juhász, A. L.; Julbe, F.; Karampelas, A.; Kewley,
A.; Klar, J.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.;
Kontizas, E.; Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska,
Z.; Koubsky, P.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; López,
M.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant,
J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall, D. J.;
Martino, M.; Marton, G.; Mary, N.; Massari, D.; Matijevič, G.;
Mazeh, T.; McMillan, P. J.; Messina, S.; Millar, N. R.; Molina, D.;
Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor, R.; Morbidelli,
R.; Morel, T.; Morris, D.; Mulone, A. F.; Muraveva, T.; Musella, I.;
Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane, W.; Ordénovic, C.;
Ordóñez-Blanco, D.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler,
F.; Palacin, H.; Palaversa, L.; Panahi, A.; Pawlak, M.; Piersimoni,
A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poujoulet,
E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.; Rambaux, N.;
Regibo, S.; Reylé, C.; Riclet, F.; Ripepi, V.; Riva, A.; Rivard,
A.; Rixon, G.; Roegiers, T.; Roelens, M.; Romero-Gómez, M.; Rowell,
N.; Royer, F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.;
Sahlmann, J.; Salgado, J.; Salguero, E.; Sanna, N.; Santana-Ros, T.;
Sarasso, M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol, M.;
Segovia, J. C.; Ségransan, D.; Shih, I. -C.; Siltala, L.; Silva,
A. F.; Smart, R. L.; Smith, K. W.; Solano, E.; Solitro, F.; Sordo,
R.; Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa, U.;
Steele, I. A.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Surdej,
J.; Szabados, L.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran,
G.; Taylor, M. B.; Teixeira, R.; Terrett, D.; Teyssandier, P.;
Thuillot, W.; Titarenko, A.; Torra Clotet, F.; Turon, C.; Ulla,
A.; Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini, G.; Valette,
V.; van Elteren, A.; Van Hemelryck, E.; van Leeuwen, M.; Vaschetto,
M.; Vecchiato, A.; Veljanoski, J.; Viala, Y.; Vicente, D.; Vogt, S.;
von Essen, C.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.;
Weiler, M.; Wertz, O.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.;
Žerjal, M.; Ziaeepour, H.; Zorec, J.; Zschocke, S.; Zucker, S.;
Zurbach, C.; Zwitter, T.
2018A&A...616A..14G Altcode: 2018arXiv180409377M
Context. The second release of Gaia data (Gaia DR2) contains the
astrometric parameters for more than half a million quasars. This set
defines a kinematically non-rotating reference frame in the optical
domain. A subset of these quasars have accurate VLBI positions
that allow the axes of the reference frame to be aligned with the
International Celestial Reference System (ICRF) radio frame. <BR
/> Aims: We describe the astrometric and photometric properties of
the quasars that were selected to represent the celestial reference
frame of Gaia DR2 (Gaia-CRF2), and to compare the optical and radio
positions for sources with accurate VLBI positions. <BR /> Methods:
Descriptive statistics are used to characterise the overall properties
of the quasar sample. Residual rotation and orientation errors and
large-scale systematics are quantified by means of expansions in vector
spherical harmonics. Positional differences are calculated relative to
a prototype version of the forthcoming ICRF3. <BR /> Results: Gaia-CRF2
consists of the positions of a sample of 556 869 sources in Gaia DR2,
obtained from a positional cross-match with the ICRF3-prototype and
AllWISE AGN catalogues. The sample constitutes a clean, dense, and
homogeneous set of extragalactic point sources in the magnitude range
G ≃ 16 to 21 mag with accurately known optical positions. The median
positional uncertainty is 0.12 mas for G < 18 mag and 0.5 mas at
G = mag. Large-scale systematics are estimated to be in the range 20
to 30 μas. The accuracy claims are supported by the parallaxes and
proper motions of the quasars in Gaia DR2. The optical positions for
a subset of 2820 sources in common with the ICRF3-prototype show very
good overall agreement with the radio positions, but several tens of
sources have significantly discrepant positions. <BR /> Conclusions:
Based on less than 40% of the data expected from the nominal Gaia
mission, Gaia-CRF2 is the first realisation of a non-rotating global
optical reference frame that meets the ICRS prescriptions, meaning
that it is built only on extragalactic sources. Its accuracy matches
the current radio frame of the ICRF, but the density of sources in
all parts of the sky is much higher, except along the Galactic equator.
---------------------------------------------------------
Title: Abundances of Mg and K in the atmospheres of turn-off starsin
Galactic globular cluster 47 Tucanae
Authors: Černiauskas, A.; Kučinskas, A.; Klevas, J.; Dobrovolskas,
V.; Korotin, S.; Bonifacio, P.; Ludwig, H. -G.; Caffau, E.; Steffen, M.
2018A&A...615A.173C Altcode: 2018arXiv180410033C
<BR /> Aims: We determined abundances of Mg and K in the atmospheres
of 53 (Mg) and 75 (K) turn-off (TO) stars of the Galactic globular
cluster 47 Tuc. The obtained abundances, together with those of Li,
O, and Na that we had earlier determined for the same sample of stars,
were used to search for possible relations between the abundances of K
and other light elements, Li, O, Na, and Mg, as well as the connections
between the chemical composition of TO stars and their kinematical
properties. <BR /> Methods: Abundances of Mg and K were determined using
archival high resolution VLT FLAMES/GIRAFFE spectra, in combination
with the one-dimensional (1D) non-local thermodynamic equilibrium
(NLTE) spectral synthesis methodology. Spectral line profiles were
computed with the MULTI code, using 1D hydrostatic ATLAS9 stellar model
atmospheres. We also utilized three-dimensional (3D) hydrodynamical
CO<SUP>5</SUP>BOLD and 1D hydrostatic LHD model atmospheres for
computing 3D-1D LTE abundance corrections for the spectral lines
of Mg and K, in order to assess the influence of convection on their
formation in the atmospheres of TO stars. <BR /> Results: The determined
average abundance-to-iron ratios and their root mean square variations
due to star-to-star abundance spreads were <[Mg/Fe]><SUP>1D
NLTE</SUP> = 0.47 ± 0.12, and <[K/Fe]><SUP>1D NLTE</SUP> = 0.39
± 0.09. Although the data suggest the possible existence of a weak
correlation in the [K/Fe]-[Na/Fe] plane, its statistical significance
is low. No statistically significant relations between the abundance
of K and other light elements were detected. Also, we did not find any
significant correlations or anti-correlations between the [Mg/Fe] and
[K/Fe] ratios and projected distance from the cluster center. Similarly,
no relations between the absolute radial velocities of individual stars
and abundances of Mg and K in their atmospheres were detected. The
3D-1D abundance corrections were found to be small (≤0.1 dex) for
the lines of Mg and K used in this study, thus indicating that the
influence of convection on their formation is small.
---------------------------------------------------------
Title: Gaia Data Release 2. Mapping the Milky Way disc kinematics
Authors: Gaia Collaboration; Katz, D.; Antoja, T.; Romero-Gómez, M.;
Drimmel, R.; Reylé, C.; Seabroke, G. M.; Soubiran, C.; Babusiaux,
C.; Di Matteo, P.; Figueras, F.; Poggio, E.; Robin, A. C.; Evans,
D. W.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne,
J. H. J.; Bailer-Jones, C. A. L.; Biermann, M.; Eyer, L.; Jansen,
F.; Jordi, C.; Klioner, S. A.; Lammers, U.; Lindegren, L.; Luri,
X.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.; Sartoretti,
P.; Siddiqui, H. I.; van Leeuwen, F.; Walton, N. A.; Arenou, F.;
Bastian, U.; Cropper, M.; Lattanzi, M. G.; Bakker, J.; Cacciari,
C.; Casta n, J.; Chaoul, L.; Cheek, N.; De Angeli, F.; Fabricius,
C.; Guerra, R.; Holl, B.; Masana, E.; Messineo, R.; Mowlavi, N.;
Nienartowicz, K.; Panuzzo, P.; Portell, J.; Riello, M.; Tanga, P.;
Thévenin, F.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.;
Teyssier, D.; Altmann, M.; Andrae, R.; Audard, M.; Bellas-Velidis,
I.; Benson, K.; Berthier, J.; Blomme, R.; Burgess, P.; Busso, G.;
Carry, B.; Cellino, A.; Clementini, G.; Clotet, M.; Creevey, O.;
Davidson, M.; De Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant,
C.; Fernández-Hernández, J.; Fouesneau, M.; Frémat, Y.; Galluccio,
L.; García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.;
Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.;
Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Löffler, W.;
Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
Mora, A.; Muinonen, K.; Osinde, J.; Pancino, E.; Pauwels, T.; Petit,
J. -M.; Recio-Blanco, A.; Richards, P. J.; Rimoldini, L.; Sarro,
L. M.; Siopis, C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.;
van Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.;
Altavilla, G.; Álvarez, M. A.; Alvarez, R.; Alves, J.; Anderson,
R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Arcay, B.;
Astraatmadja, T. L.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.;
Balm, P.; Barache, C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem,
P. S.; Barrado, D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz,
L.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.;
Bertone, S.; Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch,
T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon,
S.; Bourda, G.; Bragaglia, A.; Bramante, L.; Breddels, M. A.; Bressan,
A.; Brouillet, N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli,
B.; Burlacu, A.; Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau,
E.; Cancelliere, R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo,
R.; Carlucci, T.; Carrasco, J. M.; Casamiquela, L.; Castellani, M.;
Castro-Ginard, A.; Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza,
G.; Costigan, G.; Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.;
Cuypers, J.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.;
David, M.; de Laverny, P.; De Luise, F.; De March, R.; de Souza, R.;
de Torres, A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.;
Delgado, H. E.; Diakite, S.; Diener, C.; Distefano, E.; Dolding, C.;
Drazinos, P.; Durán, J.; Edvardsson, B.; Enke, H.; Eriksson, K.;
Esquej, P.; Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Faigler,
S.; Falc a, A. J.; Farràs Casas, M.; Federici, L.; Fedorets, G.;
Fernique, P.; Filippi, F.; Findeisen, K.; Fonti, A.; Fraile, E.;
Fraser, M.; Frézouls, B.; Gai, M.; Galleti, S.; Garabato, D.;
García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel, A.; Gavras,
P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona,
S.; Giuffrida, G.; Glass, F.; Gomes, M.; Granvik, M.; Gueguen, A.;
Guerrier, A.; Guiraud, J.; Gutié, R.; Haigron, R.; Hatzidimitriou,
D.; Hauser, M.; Haywood, M.; Heiter, U.; Helmi, A.; Heu, J.; Hilger,
T.; Hobbs, D.; Hofmann, W.; Holland, G.; Huckle, H. E.; Hypki, A.;
Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.; Jonker, P. G.;
Juhász, Á. L.; Julbe, F.; Karampelas, A.; Kewley, A.; Klar, J.;
Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.; Kontizas, E.;
Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.; Koubsky, P.;
Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; López,
M.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant,
J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall, D. J.;
Martino, M.; Marton, G.; Mary, N.; Massari, D.; Matijevič, G.; Mazeh,
T.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Molina,
D.; Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor, R.; Morbidelli,
R.; Morel, T.; Morris, D.; Mulone, A. F.; Muraveva, T.; Musella, I.;
Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane, W.; Ordénovic, C.;
Ordóñez-Blanco, D.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler,
F.; Palacin, H.; Palaversa, L.; Panahi, A.; Pawlak, M.; Piersimoni,
A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poujoulet, E.; Prša,
A.; Pulone, L.; Racero, E.; Ragaini, S.; Rambaux, N.; Ramos-Lerate,
M.; Regibo, S.; Riclet, F.; Ripepi, V.; Riva, A.; Rivard, A.; Rixon,
G.; Roegiers, T.; Roelens, M.; Rowell, N.; Royer, F.; Ruiz-Dern,
L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann, J.; Salgado, J.;
Salguero, E.; Sanna, N.; Santana-Ros, T.; Sarasso, M.; Savietto, H.;
Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Ségransan,
D.; Shih, I. -C.; Siltala, L.; Silva, A. F.; Smart, R. L.; Smith,
K. W.; Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay,
J.; Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmüller,
H.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Surdej, J.; Szabados,
L.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor,
M. B.; Teixeira, R.; Terrett, D.; Teyssandier, P.; Thuillot, W.;
Titarenko, A.; Torra Clotet, F.; Turon, C.; Ulla, A.; Utrilla, E.;
Uzzi, S.; Vaillant, M.; Valentini, G.; Valette, V.; van Elteren,
A.; Van Hemelryck, E.; van Leeuwen, M.; Vaschetto, M.; Vecchiato,
A.; Veljanoski, J.; Viala, Y.; Vicente, D.; Vogt, S.; von Essen, C.;
Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Wertz,
O.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Ziaeepour,
H.; Zorec, J.; Zschocke, S.; Zucker, S.; Zurbach, C.; Zwitter, T.
2018A&A...616A..11G Altcode: 2018arXiv180409380G
Context. The second Gaia data release (Gaia DR2) contains high-precision
positions, parallaxes, and proper motions for 1.3 billion sources as
well as line-of-sight velocities for 7.2 million stars brighter than
G<SUB>RVS</SUB> = 12 mag. Both samples provide a full sky coverage. <BR
/> Aims: To illustrate the potential of Gaia DR2, we provide a first
look at the kinematics of the Milky Way disc, within a radius of several
kiloparsecs around the Sun. <BR /> Methods: We benefit for the first
time from a sample of 6.4 million F-G-K stars with full 6D phase-space
coordinates, precise parallaxes (σ<SUB>ϖ</SUB>/ϖ ≤ 20%), and
precise Galactic cylindrical velocities (median uncertainties of 0.9-1.4
km s<SUP>-1</SUP> and 20% of the stars with uncertainties smaller than
1 km s<SUP>-1</SUP> on all three components). From this sample, we
extracted a sub-sample of 3.2 million giant stars to map the velocity
field of the Galactic disc from 5 kpc to 13 kpc from the Galactic
centre and up to 2 kpc above and below the plane. We also study the
distribution of 0.3 million solar neighbourhood stars (r < 200 pc),
with median velocity uncertainties of 0.4 km s<SUP>-1</SUP>, in velocity
space and use the full sample to examine how the over-densities evolve
in more distant regions. <BR /> Results: Gaia DR2 allows us to draw 3D
maps of the Galactocentric median velocities and velocity dispersions
with unprecedented accuracy, precision, and spatial resolution. The
maps show the complexity and richness of the velocity field of the
galactic disc. We observe streaming motions in all the components of
the velocities as well as patterns in the velocity dispersions. For
example, we confirm the previously reported negative and positive
galactocentric radial velocity gradients in the inner and outer disc,
respectively. Here, we see them as part of a non-axisymmetric kinematic
oscillation, and we map its azimuthal and vertical behaviour. We also
witness a new global arrangement of stars in the velocity plane of
the solar neighbourhood and in distant regions in which stars are
organised in thin substructures with the shape of circular arches
that are oriented approximately along the horizontal direction in the
U - V plane. Moreover, in distant regions, we see variations in the
velocity substructures more clearly than ever before, in particular,
variations in the velocity of the Hercules stream. <BR /> Conclusions:
Gaia DR2 provides the largest existing full 6D phase-space coordinates
catalogue. It also vastly increases the number of available distances
and transverse velocities with respect to Gaia DR1. Gaia DR2 offers
a great wealth of information on the Milky Way and reveals clear
non-axisymmetric kinematic signatures within the Galactic disc, for
instance. It is now up to the astronomical community to explore its
full potential.
---------------------------------------------------------
Title: Gaia Data Release 2. Observational Hertzsprung-Russell diagrams
Authors: Gaia Collaboration; Babusiaux, C.; van Leeuwen, F.;
Barstow, M. A.; Jordi, C.; Vallenari, A.; Bossini, D.; Bressan,
A.; Cantat-Gaudin, T.; van Leeuwen, M.; Brown, A. G. A.; Prusti,
T.; de Bruijne, J. H. J.; Bailer-Jones, C. A. L.; Biermann, M.;
Evans, D. W.; Eyer, L.; Jansen, F.; Klioner, S. A.; Lammers, U.;
Lindegren, L.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.;
Randich, S.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; Walton,
N. A.; Arenou, F.; Bastian, U.; Cropper, M.; Drimmel, R.; Katz, D.;
Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castañeda, J.; Chaoul,
L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.; Holl, B.;
Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Panuzzo,
P.; Portell, J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thévenin,
F.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Teyssier,
D.; Altmann, M.; Andrae, R.; Audard, M.; Bellas-Velidis, I.; Benson,
K.; Berthier, J.; Blomme, R.; Burgess, P.; Busso, G.; Carry, B.;
Cellino, A.; Clementini, G.; Clotet, M.; Creevey, O.; Davidson,
M.; De Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.;
Fernández-Hernández, J.; Fouesneau, M.; Frémat, Y.; Galluccio, L.;
García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.;
Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.;
Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Löffler, W.;
Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
Mora, A.; Muinonen, K.; Osinde, J.; Pancino, E.; Pauwels, T.; Petit,
J. -M.; Recio-Blanco, A.; Richards, P. J.; Rimoldini, L.; Robin,
A. C.; Sarro, L. M.; Siopis, C.; Smith, M.; Sozzetti, A.; Süveges,
M.; Torra, J.; van Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart,
S.; Aerts, C.; Altavilla, G.; Álvarez, M. A.; Alvarez, R.; Alves,
J.; Anderson, R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.;
Antoja, T.; Arcay, B.; Astraatmadja, T. L.; Bach, N.; Baker, S. G.;
Balaguer-Núñez, L.; Balm, P.; Barache, C.; Barata, C.; Barbato,
D.; Barblan, F.; Barklem, P. S.; Barrado, D.; Barros, M.; Bartholomé
Muñoz, L.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.; Berihuete,
A.; Bertone, S.; Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.;
Boch, T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bouquillon, S.;
Bourda, G.; Bragaglia, A.; Bramante, L.; Breddels, M. A.; Brouillet,
N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.;
Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere,
R.; Cannizzaro, G.; Carballo, R.; Carlucci, T.; Carrasco, J. M.;
Casamiquela, L.; Castellani, M.; Castro-Ginard, A.; Charlot, P.;
Chemin, L.; Chiavassa, A.; Cocozza, G.; Costigan, G.; Cowell,
S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers, J.; Dafonte, C.;
Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; de Laverny, P.;
De Luise, F.; De March, R.; de Martino, D.; de Souza, R.; de Torres,
A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.; Delgado,
H. E.; Diakite, S.; Diener, C.; Distefano, E.; Dolding, C.; Drazinos,
P.; Durán, J.; Edvardsson, B.; Enke, H.; Eriksson, K.; Esquej, P.;
Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Faigler, S.; Falcão,
A. J.; Farràs Casas, M.; Federici, L.; Fedorets, G.; Fernique,
P.; Figueras, F.; Filippi, F.; Findeisen, K.; Fonti, A.; Fraile,
E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti, S.; Garabato, D.;
García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel, A.; Gavras,
P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona,
S.; Giuffrida, G.; Glass, F.; Gomes, M.; Granvik, M.; Gueguen, A.;
Guerrier, A.; Guiraud, J.; Gutié, R.; Haigron, R.; Hatzidimitriou,
D.; Hauser, M.; Haywood, M.; Heiter, U.; Helmi, A.; Heu, J.; Hilger,
T.; Hobbs, D.; Hofmann, W.; Holland, G.; Huckle, H. E.; Hypki, A.;
Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.; Jonker, P. G.;
Juhász, Á. L.; Julbe, F.; Karampelas, A.; Kewley, A.; Klar, J.;
Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.; Kontizas, E.;
Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.; Koubsky, P.;
Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; López,
M.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant,
J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall, D. J.;
Martino, M.; Marton, G.; Mary, N.; Massari, D.; Matijevič, G.; Mazeh,
T.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Molina,
D.; Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor, R.; Morbidelli,
R.; Morel, T.; Morris, D.; Mulone, A. F.; Muraveva, T.; Musella, I.;
Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane, W.; Ordénovic, C.;
Ordóñez-Blanco, D.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.;
Palacin, H.; Palaversa, L.; Panahi, A.; Pawlak, M.; Piersimoni, A. M.;
Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poujoulet, E.; Prša,
A.; Pulone, L.; Racero, E.; Ragaini, S.; Rambaux, N.; Ramos-Lerate,
M.; Regibo, S.; Reylé, C.; Riclet, F.; Ripepi, V.; Riva, A.; Rivard,
A.; Rixon, G.; Roegiers, T.; Roelens, M.; Romero-Gómez, M.; Rowell,
N.; Royer, F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.;
Sahlmann, J.; Salgado, J.; Salguero, E.; Sanna, N.; Santana-Ros, T.;
Sarasso, M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol, M.;
Segovia, J. C.; Ségransan, D.; Shih, I. -C.; Siltala, L.; Silva,
A. F.; Smart, R. L.; Smith, K. W.; Solano, E.; Solitro, F.; Sordo,
R.; Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa,
U.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.; Stoev, H.;
Suess, F. F.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.; Tapiador,
D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Terrett,
D.; Teyssandier, P.; Thuillot, W.; Titarenko, A.; Torra Clotet, F.;
Turon, C.; Ulla, A.; Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini,
G.; Valette, V.; van Elteren, A.; Van Hemelryck, E.; Vaschetto, M.;
Vecchiato, A.; Veljanoski, J.; Viala, Y.; Vicente, D.; Vogt, S.;
von Essen, C.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.;
Weiler, M.; Wertz, O.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.;
Žerjal, M.; Ziaeepour, H.; Zorec, J.; Zschocke, S.; Zucker, S.;
Zurbach, C.; Zwitter, T.
2018A&A...616A..10G Altcode: 2018arXiv180409378G
Context. Gaia Data Release 2 provides high-precision astrometry and
three-band photometry for about 1.3 billion sources over the full
sky. The precision, accuracy, and homogeneity of both astrometry and
photometry are unprecedented. <BR /> Aims: We highlight the power of
the Gaia DR2 in studying many fine structures of the Hertzsprung-Russell
diagram (HRD). Gaia allows us to present many different HRDs, depending
in particular on stellar population selections. We do not aim here
for completeness in terms of types of stars or stellar evolutionary
aspects. Instead, we have chosen several illustrative examples. <BR />
Methods: We describe some of the selections that can be made in Gaia
DR2 to highlight the main structures of the Gaia HRDs. We select both
field and cluster (open and globular) stars, compare the observations
with previous classifications and with stellar evolutionary tracks,
and we present variations of the Gaia HRD with age, metallicity, and
kinematics. Late stages of stellar evolution such as hot subdwarfs,
post-AGB stars, planetary nebulae, and white dwarfs are also analysed,
as well as low-mass brown dwarf objects. <BR /> Results: The Gaia HRDs
are unprecedented in both precision and coverage of the various Milky
Way stellar populations and stellar evolutionary phases. Many fine
structures of the HRDs are presented. The clear split of the white
dwarf sequence into hydrogen and helium white dwarfs is presented
for the first time in an HRD. The relation between kinematics and the
HRD is nicely illustrated. Two different populations in a classical
kinematic selection of the halo are unambiguously identified in the
HRD. Membership and mean parameters for a selected list of open
clusters are provided. They allow drawing very detailed cluster
sequences, highlighting fine structures, and providing extremely
precise empirical isochrones that will lead to more insight in
stellar physics. <BR /> Conclusions: Gaia DR2 demonstrates the
potential of combining precise astrometry and photometry for large
samples for studies in stellar evolution and stellar population
and opens an entire new area for HRD-based studies. <P />The full
Table A.1 is only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> (<A
href="http://cdsarc.u-strasbg.fr">http://130.79.128.5</A>) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/616/A10">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/616/A10</A>
---------------------------------------------------------
Title: Gaia Data Release 2. Kinematics of globular clusters and
dwarf galaxies around the Milky Way
Authors: Gaia Collaboration; Helmi, A.; van Leeuwen, F.; McMillan,
P. J.; Massari, D.; Antoja, T.; Robin, A. C.; Lindegren, L.;
Bastian, U.; Arenou, F.; Babusiaux, C.; Biermann, M.; Breddels,
M. A.; Hobbs, D.; Jordi, C.; Pancino, E.; Reylé, C.; Veljanoski,
J.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne,
J. H. J.; Bailer-Jones, C. A. L.; Evans, D. W.; Eyer, L.; Jansen,
F.; Klioner, S. A.; Lammers, U.; Luri, X.; Mignard, F.; Panem,
C.; Pourbaix, D.; Randich, S.; Sartoretti, P.; Siddiqui, H. I.;
Soubiran, C.; Walton, N. A.; Cropper, M.; Drimmel, R.; Katz, D.;
Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castañeda, J.; Chaoul,
L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.; Holl, B.;
Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Panuzzo,
P.; Portell, J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thévenin,
F.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Teyssier,
D.; Altmann, M.; Andrae, R.; Audard, M.; Bellas-Velidis, I.; Benson,
K.; Berthier, J.; Blomme, R.; Burgess, P.; Busso, G.; Carry, B.;
Cellino, A.; Clementini, G.; Clotet, M.; Creevey, O.; Davidson,
M.; De Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.;
Fernández-Hernández, J.; Fouesneau, M.; Frémat, Y.; Galluccio, L.;
García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.;
Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.;
Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Löffler, W.;
Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
Mora, A.; Muinonen, K.; Osinde, J.; Pauwels, T.; Petit, J. -M.;
Recio-Blanco, A.; Richards, P. J.; Rimoldini, L.; Sarro, L. M.;
Siopis, C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.; van
Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.;
Altavilla, G.; Álvarez, M. A.; Alvarez, R.; Alves, J.; Anderson,
R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Arcay, B.;
Astraatmadja, T. L.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.;
Balm, P.; Barache, C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem,
P. S.; Barrado, D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz,
S.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.;
Bertone, S.; Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch,
T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon,
S.; Bourda, G.; Bragaglia, A.; Bramante, L.; Bressan, A.; Brouillet,
N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.;
Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere,
R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.;
Carrasco, J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard, A.;
Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza, G.; Costigan, G.;
Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers, J.; Dafonte,
C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; de Laverny,
P.; De Luise, F.; De March, R.; de Martino, D.; de Souza, R.; de
Torres, A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.;
Delgado, H. E.; Di Matteo, P.; Diakite, S.; Diener, C.; Distefano,
E.; Dolding, C.; Drazinos, P.; Durán, J.; Edvardsson, B.; Enke, H.;
Eriksson, K.; Esquej, P.; Eynard Bontemps, G.; Fabre, C.; Fabrizio,
M.; Faigler, S.; Falcão, A. J.; Farràs Casas, M.; Federici, L.;
Fedorets, G.; Fernique, P.; Figueras, F.; Filippi, F.; Findeisen, K.;
Fonti, A.; Fraile, E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti, S.;
Garabato, D.; García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel,
A.; Gavras, P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore, G.;
Girona, S.; Giuffrida, G.; Glass, F.; Gomes, M.; Granvik, M.; Gueguen,
A.; Guerrier, A.; Guiraud, J.; Gutiérrez-Sánchez, R.; Hofmann,
W.; Holland, G.; Huckle, H. E.; Hypki, A.; Icardi, V.; Janßen, K.;
Jevardat de Fombelle, G.; Jonker, P. G.; Juhász, Á. L.; Julbe,
F.; Karampelas, A.; Kewley, A.; Klar, J.; Kochoska, A.; Kohley, R.;
Kolenberg, K.; Kontizas, M.; Kontizas, E.; Koposov, S. E.; Kordopatis,
G.; Kostrzewa-Rutkowska, Z.; Koubsky, P.; Lambert, S.; Lanza, A. F.;
Lasne, Y.; Lavigne, J. -B.; Le Fustec, Y.; Le Poncin-Lafitte, C.;
Lebreton, Y.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Lenhardt,
H.; Leroux, F.; Liao, S.; Licata, E.; Lindstrøm, H. E. P.; Lister,
T. A.; Livanou, E.; Lobel, A.; López, M.; Managau, S.; Mann, R. G.;
Mantelet, G.; Marchal, O.; Marchant, J. M.; Marconi, M.; Marinoni,
S.; Marschalkó, G.; Marshall, D. J.; Martino, M.; Marton, G.; Mary,
N.; Matijevič, G.; Mazeh, T.; Messina, S.; Michalik, D.; Millar,
N. R.; Molina, D.; Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor,
R.; Morbidelli, R.; Morel, T.; Morris, D.; Mulone, A. F.; Muraveva,
T.; Musella, I.; Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane, W.;
Ordénovic, C.; Ordóñez-Blanco, D.; Osborne, P.; Pagani, C.; Pagano,
I.; Pailler, F.; Palacin, H.; Palaversa, L.; Panahi, A.; Pawlak, M.;
Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.;
Poujoulet, E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.; Rambaux,
N.; Ramos-Lerate, M.; Regibo, S.; Riclet, F.; Ripepi, V.; Riva, A.;
Rivard, A.; Rixon, G.; Roegiers, T.; Roelens, M.; Romero-Gómez, M.;
Rowell, N.; Royer, F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés,
T.; Sahlmann, J.; Salgado, J.; Salguero, E.; Sanna, N.; Santana-Ros,
T.; Sarasso, M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol,
M.; Segovia, J. C.; Ségransan, D.; Shih, I. -C.; Siltala, L.; Silva,
A. F.; Smart, R. L.; Smith, K. W.; Solano, E.; Solitro, F.; Sordo,
R.; Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa,
U.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.; Stoev, H.;
Suess, F. F.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.; Tapiador,
D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Terrett, D.;
Teyssandier, P.; Thuillot, W.; Titarenko, A.; Torra Clotet, F.;
Turon, C.; Ulla, A.; Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini,
G.; Valette, V.; van Elteren, A.; Van Hemelryck, E.; van Leeuwen,
M.; Vaschetto, M.; Vecchiato, A.; Viala, Y.; Vicente, D.; Vogt, S.;
von Essen, C.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.;
Weiler, M.; Wertz, O.; Wevems, T.; Wyrzykowski, Ł.; Yoldas, A.;
Žerjal, M.; Ziaeepour, H.; Zorec, J.; Zschocke, S.; Zucker, S.;
Zurbach, C.; Zwitter, T.
2018A&A...616A..12G Altcode: 2018arXiv180409381G
Note to the Readers: Following the publication of the <A
href="https://www.aanda.org/articles/aa/full_html/2020/05/aa32698e-18/aa32698e-18.html">corrigendum</A>,
the article was corrected on 15 May 2020. <P />Context. <BR /> Aims:
The goal of this paper is to demonstrate the outstanding quality
of the second data release of the Gaia mission and its power for
constraining many different aspects of the dynamics of the satellites
of the Milky Way. We focus here on determining the proper motions of
75 Galactic globular clusters, nine dwarf spheroidal galaxies, one
ultra-faint system, and the Large and Small Magellanic Clouds. <BR
/> Methods: Using data extracted from the Gaia archive, we derived
the proper motions and parallaxes for these systems, as well as
their uncertainties. We demonstrate that the errors, statistical
and systematic, are relatively well understood. We integrated the
orbits of these objects in three different Galactic potentials, and
characterised their properties. We present the derived proper motions,
space velocities, and characteristic orbital parameters in various
tables to facilitate their use by the astronomical community. <BR />
Results: Our limited and straightforward analyses have allowed us
for example to (i) determine absolute and very precise proper motions
for globular clusters; (ii) detect clear rotation signatures in the
proper motions of at least five globular clusters; (iii) show that
the satellites of the Milky Way are all on high-inclination orbits,
but that they do not share a single plane of motion; (iv) derive a lower
limit for the mass of the Milky Way of 9.1<SUB>-2.6</SUB><SUP>+6.2</SUP>
× 10<SUP>11</SUP> M<SUB>⊙</SUB> based on the assumption that the Leo
I dwarf spheroidal is bound; (v) derive a rotation curve for the Large
Magellanic Cloud based solely on proper motions that is competitive
with line-of-sight velocity curves, now using many orders of magnitude
more sources; and (vi) unveil the dynamical effect of the bar on the
motions of stars in the Large Magellanic Cloud. <BR /> Conclusions: All
these results highlight the incredible power of the Gaia astrometric
mission, and in particular of its second data release. <P />Full
Table D.3 is only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> (<A
href="http://cdsarc.u-strasbg.fr">http://130.79.128.5</A>) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/616/A12">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/616/A12</A>
---------------------------------------------------------
Title: Gaia Data Release 2. Summary of the contents and survey
properties
Authors: Gaia Collaboration; Brown, A. G. A.; Vallenari, A.; Prusti,
T.; de Bruijne, J. H. J.; Babusiaux, C.; Bailer-Jones, C. A. L.;
Biermann, M.; Evans, D. W.; Eyer, L.; Jansen, F.; Jordi, C.; Klioner,
S. A.; Lammers, U.; Lindegren, L.; Luri, X.; Mignard, F.; Panem,
C.; Pourbaix, D.; Randich, S.; Sartoretti, P.; Siddiqui, H. I.;
Soubiran, C.; van Leeuwen, F.; Walton, N. A.; Arenou, F.; Bastian,
U.; Cropper, M.; Drimmel, R.; Katz, D.; Lattanzi, M. G.; Bakker,
J.; Cacciari, C.; Castañeda, J.; Chaoul, L.; Cheek, N.; De Angeli,
F.; Fabricius, C.; Guerra, R.; Holl, B.; Masana, E.; Messineo, R.;
Mowlavi, N.; Nienartowicz, K.; Panuzzo, P.; Portell, J.; Riello,
M.; Seabroke, G. M.; Tanga, P.; Thévenin, F.; Gracia-Abril, G.;
Comoretto, G.; Garcia-Reinaldos, M.; Teyssier, D.; Altmann, M.;
Andrae, R.; Audard, M.; Bellas-Velidis, I.; Benson, K.; Berthier,
J.; Blomme, R.; Burgess, P.; Busso, G.; Carry, B.; Cellino, A.;
Clementini, G.; Clotet, M.; Creevey, O.; Davidson, M.; De Ridder, J.;
Delchambre, L.; Dell'Oro, A.; Ducourant, C.; Fernández-Hernández,
J.; Fouesneau, M.; Frémat, Y.; Galluccio, L.; García-Torres,
M.; González-Núñez, J.; González-Vidal, J. J.; Gosset, E.; Guy,
L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison, D. L.; Hernández,
J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.; Jasniewicz, G.;
Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.; Krone-Martins, A.;
Lanzafame, A. C.; Lebzelter, T.; Löffler, W.; Manteiga, M.; Marrese,
P. M.; Martín-Fleitas, J. M.; Moitinho, A.; Mora, A.; Muinonen, K.;
Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J. -M.; Recio-Blanco, A.;
Richards, P. J.; Rimoldini, L.; Robin, A. C.; Sarro, L. M.; Siopis,
C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.; van Reeven, W.;
Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.; Altavilla, G.;
Álvarez, M. A.; Alvarez, R.; Alves, J.; Anderson, R. I.; Andrei,
A. H.; Anglada Varela, E.; Antiche, E.; Antoja, T.; Arcay, B.;
Astraatmadja, T. L.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.;
Balm, P.; Barache, C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem,
P. S.; Barrado, D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz,
S.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.;
Bertone, S.; Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch,
T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon,
S.; Bourda, G.; Bragaglia, A.; Bramante, L.; Breddels, M. A.; Bressan,
A.; Brouillet, N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli,
B.; Burlacu, A.; Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau,
E.; Cancelliere, R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo,
R.; Carlucci, T.; Carrasco, J. M.; Casamiquela, L.; Castellani, M.;
Castro-Ginard, A.; Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza, G.;
Costigan, G.; Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers,
J.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.;
de Laverny, P.; De Luise, F.; De March, R.; de Martino, D.; de Souza,
R.; de Torres, A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado,
A.; Delgado, H. E.; Di Matteo, P.; Diakite, S.; Diener, C.; Distefano,
E.; Dolding, C.; Drazinos, P.; Durán, J.; Edvardsson, B.; Enke, H.;
Eriksson, K.; Esquej, P.; Eynard Bontemps, G.; Fabre, C.; Fabrizio,
M.; Faigler, S.; Falcão, A. J.; Farràs Casas, M.; Federici, L.;
Fedorets, G.; Fernique, P.; Figueras, F.; Filippi, F.; Findeisen, K.;
Fonti, A.; Fraile, E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti, S.;
Garabato, D.; García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel,
A.; Gavras, P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore, G.;
Girona, S.; Giuffrida, G.; Glass, F.; Gomes, M.; Granvik, M.; Gueguen,
A.; Guerrier, A.; Guiraud, J.; Gutiérrez-Sánchez, R.; Haigron, R.;
Hatzidimitriou, D.; Hauser, M.; Haywood, M.; Heiter, U.; Helmi, A.;
Heu, J.; Hilger, T.; Hobbs, D.; Hofmann, W.; Holland, G.; Huckle,
H. E.; Hypki, A.; Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.;
Jonker, P. G.; Juhász, Á. L.; Julbe, F.; Karampelas, A.; Kewley,
A.; Klar, J.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.;
Kontizas, E.; Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.;
Koubsky, P.; Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.;
Le Fustec, Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.;
Leclerc, N.; Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.;
Licata, E.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel,
A.; López, M.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.;
Marchant, J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall,
D. J.; Martino, M.; Marton, G.; Mary, N.; Massari, D.; Matijevič,
G.; Mazeh, T.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar,
N. R.; Molina, D.; Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor,
R.; Morbidelli, R.; Morel, T.; Morris, D.; Mulone, A. F.; Muraveva,
T.; Musella, I.; Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane,
W.; Ordénovic, C.; Ordóñez-Blanco, D.; Osborne, P.; Pagani, C.;
Pagano, I.; Pailler, F.; Palacin, H.; Palaversa, L.; Panahi, A.;
Pawlak, M.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum,
G.; Poggio, E.; Poujoulet, E.; Prša, A.; Pulone, L.; Racero, E.;
Ragaini, S.; Rambaux, N.; Ramos-Lerate, M.; Regibo, S.; Reylé, C.;
Riclet, F.; Ripepi, V.; Riva, A.; Rivard, A.; Rixon, G.; Roegiers,
T.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer, F.; Ruiz-Dern,
L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann, J.; Salgado, J.;
Salguero, E.; Sanna, N.; Santana-Ros, T.; Sarasso, M.; Savietto, H.;
Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Ségransan, D.;
Shih, I. -C.; Siltala, L.; Silva, A. F.; Smart, R. L.; Smith, K. W.;
Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.;
Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmüller, H.;
Stephenson, C. A.; Stoev, H.; Suess, F. F.; Surdej, J.; Szabados, L.;
Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor,
M. B.; Teixeira, R.; Terrett, D.; Teyssandier, P.; Thuillot, W.;
Titarenko, A.; Torra Clotet, F.; Turon, C.; Ulla, A.; Utrilla, E.;
Uzzi, S.; Vaillant, M.; Valentini, G.; Valette, V.; van Elteren,
A.; Van Hemelryck, E.; van Leeuwen, M.; Vaschetto, M.; Vecchiato,
A.; Veljanoski, J.; Viala, Y.; Vicente, D.; Vogt, S.; von Essen, C.;
Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Wertz,
O.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Ziaeepour,
H.; Zorec, J.; Zschocke, S.; Zucker, S.; Zurbach, C.; Zwitter, T.
2018A&A...616A...1G Altcode: 2018arXiv180409365G
Context. We present the second Gaia data release, Gaia DR2, consisting
of astrometry, photometry, radial velocities, and information on
astrophysical parameters and variability, for sources brighter than
magnitude 21. In addition epoch astrometry and photometry are provided
for a modest sample of minor planets in the solar system. <BR />
Aims: A summary of the contents of Gaia DR2 is presented, accompanied
by a discussion on the differences with respect to Gaia DR1 and
an overview of the main limitations which are still present in
the survey. Recommendations are made on the responsible use of
Gaia DR2 results. <BR /> Methods: The raw data collected with the
Gaia instruments during the first 22 months of the mission have
been processed by the Gaia Data Processing and Analysis Consortium
(DPAC) and turned into this second data release, which represents
a major advance with respect to Gaia DR1 in terms of completeness,
performance, and richness of the data products. <BR /> Results: Gaia
DR2 contains celestial positions and the apparent brightness in G for
approximately 1.7 billion sources. For 1.3 billion of those sources,
parallaxes and proper motions are in addition available. The sample
of sources for which variability information is provided is expanded
to 0.5 million stars. This data release contains four new elements:
broad-band colour information in the form of the apparent brightness
in the G<SUB>BP</SUB> (330-680 nm) and G<SUB>RP</SUB> (630-1050 nm)
bands is available for 1.4 billion sources; median radial velocities for
some 7 million sources are presented; for between 77 and 161 million
sources estimates are provided of the stellar effective temperature,
extinction, reddening, and radius and luminosity; and for a pre-selected
list of 14 000 minor planets in the solar system epoch astrometry
and photometry are presented. Finally, Gaia DR2 also represents a
new materialisation of the celestial reference frame in the optical,
the Gaia-CRF2, which is the first optical reference frame based solely
on extragalactic sources. There are notable changes in the photometric
system and the catalogue source list with respect to Gaia DR1, and we
stress the need to consider the two data releases as independent. <BR
/> Conclusions: Gaia DR2 represents a major achievement for the Gaia
mission, delivering on the long standing promise to provide parallaxes
and proper motions for over 1 billion stars, and representing a first
step in the availability of complementary radial velocity and source
astrophysical information for a sample of stars in the Gaia survey
which covers a very substantial fraction of the volume of our galaxy.
---------------------------------------------------------
Title: VizieR Online Data Catalog: A(Li) and 6Li/7Li 3D NLTE
corrections (Harutyunyan+, 2018)
Authors: Harutyunyan, G.; Steffen, M.; Mott, A.; Caffau, E.; Israelian,
G.; Gonzalez Hernandez, J. I.; Strassmeier, K. G.
2018yCat..36180016H Altcode:
A grid of 3D non-LTE (NLTE) corrections for the lithium abundance,
A(Li), and the <SUP>6</SUP>Li/<SUP>7</SUP>Li isotopic ratio are
presented. These corrections can be easily applied to correct 1D
LTE lithium abundances in G and F dwarf stars of approximately
solar mass and metallicity for 3D and NLTE effects. The stellar
parameters defining the grid are effective temperatures, Teff (5900,
6300 and 6500K), surface gravity, logg (4.0 and 4.5), metallicity,
[Fe/H] (-1.0, -0.5, 0.0, +0.5), 1D LTE lithium abundance, A(Li)
(1.5, 2.0, 2.5), 1D LTE <SUP>6</SUP>Li/<SUP>7</SUP>Li isotopic ratio
(0, 5 and 10%), as well as projected rotational velocity, vsini (0,
2, 4 and 6km/s). Based on this table, a web page calculator was
created that allows to compute the 3D NLTE corrections of A(Li)
and 6Li/7Li ratio for a given combination of stellar parameters
(https://pages.aip.de/li67nlte3d/). <P />(1 data file).
---------------------------------------------------------
Title: Investigation of a sample of carbon-enhanced metal-poor stars
observed with FORS and GMOS
Authors: Caffau, E.; Gallagher, A. J.; Bonifacio, P.; Spite, M.;
Duffau, S.; Spite, F.; Monaco, L.; Sbordone, L.
2018A&A...614A..68C Altcode: 2018arXiv180309252C
<BR /> Aims: Carbon-enhanced metal-poor (CEMP) stars represent a
sizeable fraction of all known metal-poor stars in the Galaxy. Their
formation and composition remains a significant topic of investigation
within the stellar astrophysics community. <BR /> Methods: We analysed
a sample of low-resolution spectra of 30 dwarf stars, obtained using
the visual and near UV FOcal Reducer and low dispersion Spectrograph
for the Very Large Telescope (FORS/VLT) of the European Southern
Observatory (ESO) and the Gemini Multi-Object Spectrographs (GMOS)
at the GEMINI telescope, to derive their metallicity and carbon
abundance. <BR /> Results: We derived C and Ca from all spectra,
and Fe and Ba from the majority of the stars. <BR /> Conclusions:
We have extended the population statistics of CEMP stars and have
confirmed that in general, stars with a high C abundance belonging
to the high C band show a high Ba-content (CEMP-s or -r/s), while
stars with a normal C abundance or that are C-rich, but belong to the
low C band, are normal in Ba (CEMP-no). <P />Based on observations
made with ESO Telescopes at the La Silla Paranal Observatory under
programme ID 099.D-0791. <P />Based on observations obtained at the
Gemini Observatory (processed using the Gemini IRAF package), which is
operated by the Association of Universities for Research in Astronomy,
Inc., under a cooperative agreement with the NSF on behalf of the
Gemini partnership: the National Science Foundation (United States),
the National Research Council (Canada), CONICYT (Chile), Ministerio
de Ciencia, Tecnología e Innovación Productiva (Argentina),
and Ministério da Ciência, Tecnologia e Inovação (Brazil). <P
/>Tables 1 and 2 are also available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/614/A68">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/614/A68</A>
---------------------------------------------------------
Title: VizieR Online Data Catalog: Carbon-enhanced metal-poor stars
sample (Caffau+, 2018)
Authors: Caffau, E.; Gallagher, A. J.; Bonifacio, P.; Spite, M.;
Duffau, S.; Spite, F.; Monaco, L.; Sbordone, L.
2018yCat..36140068C Altcode:
We selected a sample of turn-off stars from the Sloan Digital Sky
Survey (SDSS York et al. 2000AJ....120.1579Y; Yanny et al. 2009,
Cat. J/AJ/137/4377) that were bright enough (g<17) to allow us to
secure a reasonable spectrum quality in a single observing block of
1h. <P />The FORS spectra have been observed in service mode during
the ESO Programme 099.D-0791, between 01/04/2017 and 16/08/2017. <P
/>The GMOS spectra were acquired in service mode on the nights of
21/07/2017 and 25/07/2017. <P />Table 1 lists the stars we examined
here, along with their coordinates, g-mag, and metallicities derived
from Fe abundances computed using SDSS and FORS/GMOS spectra. <P />(2
data files).
---------------------------------------------------------
Title: Using the CIFIST grid of CO<SUP>5</SUP>BOLD 3D model
atmospheres to study the effects of stellar granulation on photometric
colours. II. The role of convection across the H-R diagram
Authors: Kučinskas, A.; Klevas, J.; Ludwig, H. -G.; Bonifacio, P.;
Steffen, M.; Caffau, E.
2018A&A...613A..24K Altcode: 2018arXiv180200073K
<BR /> Aims: We studied the influence of convection on the spectral
energy distributions (SEDs), photometric magnitudes, and colour
indices of different types of stars across the H-R diagram. <BR />
Methods: The 3D hydrodynamical CO<SUP>5</SUP>BOLD, averaged ⟨3D⟩,
and 1D hydrostatic LHD model atmospheres were used to compute SEDs
of stars on the main sequence (MS), main sequence turn-off (TO),
subgiant branch (SGB), and red giant branch (RGB), in each case at
two different effective temperatures and two metallicities, [M/H] =
0.0 and - 2.0. Using the obtained SEDs, we calculated photometric
magnitudes and colour indices in the broad-band Johnson-Cousins
UBVRI and 2MASS JHK<SUB>s</SUB>, and the medium-band Strömgren
uvby photometric systems. <BR /> Results: The 3D-1D differences in
photometric magnitudes and colour indices are small in both photometric
systems and typically do not exceed ± 0.03 mag. Only in the case of the
coolest giants located on the upper RGB are the differences in the U and
u bands able reach ≈-0.2 mag at [M/H] = 0.0 and ≈-0.1 mag at [M/H]
= -2.0. Generally, the 3D-1D differences are largest in the blue-UV
part of the spectrum and decrease towards longer wavelengths. They
are also sensitive to the effective temperature and are significantly
smaller in hotter stars. Metallicity also plays a role and leads to
slightly larger 3D-1D differences at [M/H] = 0.0. All these patterns are
caused by a complex interplay between the radiation field, opacities,
and horizontal temperature fluctuations that occur due to convective
motions in stellar atmospheres. Although small, the 3D-1D differences
in the magnitudes and colour indices are nevertheless comparable to
or larger than typical photometric uncertainties and may therefore
cause non-negligible systematic differences in the estimated effective
temperatures.
---------------------------------------------------------
Title: Gaia Confirms that SDSS J102915+172927 is a Dwarf Star
Authors: Bonifacio, P.; Caffau, E.; Spite, M.; Spite, F.; François,
P.; Zaggia, S.; Arenou, F.; Haigron, R.; Leclerc, N.; Marchal, O.;
Panuzzo, P.; Plum, G.; Sartoretti, P.
2018RNAAS...2...19B Altcode: 2018arXiv180410419B; 2018RNAAS...2b..19B
The Gaia Data Release 2 provides a parallax of 0.734+/-0.073 mas for
SDSS J102915+172927, currently the most metal-poor known object. This
parallax implies that it is dwarf star, ruling out the scenario that it
is a subgiant. The subgiant scenario had as a corollary that the star
had been formed in a medium highly enriched in C, thus making line
cooling efficient during the collapse, that was also highly enriched
in Fe by Type Ia SNe. This scenario can also now be ruled out for
this star, reinforcing the need of dust cooling and fragmentation to
explain its formation.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Gaia DR2 sources in GC and dSph
(Gaia Collaboration+, 2018)
Authors: Gaia Collaboration; Helmi, A.; van Leeuwen, F.; Mc
Millan, P. J.; Massari, D.; Antoja, T.; Robin, A. C.; Lindegren,
L.; Bastian, U.; Arenou, F.; Babusiaux, C.; Biermann, M.; Breddels,
M. A.; Hobbs, D.; Jordi, C.; Pancino, E.; Reyle, C.; Veljanoski, J.;
Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.;
Bailer-Jones, C. A. L.; Evans, D. W.; Eyer, L.; Jansen, F.; Klioner,
S. A.; Lammers, U.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.;
Randich, S.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; Walton,
N. A.; Cropper, M.; Drimmel, R.; Katz, D.; Lattanzi, M. G.; Bakker,
J.; Cacciari, C.; Castaneda, J.; Chaoul, L.; Cheek, N.; de Angeli,
F.; Fabricius, C.; Guerra, R.; Holl, B.; Masana, E.; Messineo, R.;
Mowlavi, N.; Nienartowicz, K.; Panuzzo, P.; Portell, J.; Riello, M.;
Seabroke, G. M.; Tanga, P.; Thevenin, F.; Gracia-Abril, G.; Comoretto,
G.; Garcia-Reinaldos, M.; Teyssier, D.; Altmann, M.; Andrae, R.;
Audard, M.; Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme,
R.; Burgess, P.; Busso, G.; Carry, B.; Cellino, A.; Clementini, G.;
Clotet, M.; ! Creevey, O.; Davidson, M.; De Ridder, J.; Delchambre,
L.; Dell'Oro, A.; Ducourant, C.; Fernandez-Hernandez, J.; Fouesneau,
M.; Fremat, Y.; Galluccio, L.; Garcia-Torres, M.; Gonzalez-Nunez,
J.; Gonzalez-Vidal, J. J.; Gosset, E.; Guy, L. P.; Halbwachs, J. -L.;
Hambly, N. C.; Harrison, D. L.; Hernandez, J.; Hestroffer, D.; Hodgkin,
S. T.; Hutton, A.; Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan,
S.; Korn, A. J.; Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.;
Loeffler, W.; Manteiga, M.; Marrese, P. M.; Martin-Fleitas, J. M.;
Moitinho, A.; Mora, A.; Muinonen, K.; Osinde, J.; Pauwels, T.; Petit,
J. -M.; Recio-Blanco, A.; Richards, P. J.; Rimoldini, L.; Sarro,
L. M.; Siopis, C.; Smith, M.; Sozzetti, A.; Sueveges, M.; Torra, J.;
van Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts,
C.; Altavilla, G.; Alvarez, M. A.; Alvarez, R.; Alves, J.; Anderson,
R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Arcay, B.;
Astraatmadja, T. L.; Bach, N.; Baker, S. G.; Balaguer-Nunez, L.;
Balm, P.; Barache, C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem,
P. S.; Barra! Do, D.; Ba Rros, M.; Barstow, M. A.; Bartholome Munoz,
S.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.; Berihuete,
A.; Bertone, S.; Bianchi, L.; Bienayme, O.; Blanco-Cuaresma, S.;
Boch, T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bossini, D.;
Bouquillon, S.; Bourda, G.; Bragaglia, A.; Bramante, L.; Bressan,
A.; Brouillet, N.; Bruesemeister, T.; Brugaletta, E.; Bucciarelli,
B.; Burlacu, A.; Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau,
E.; Cancelliere, R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo,
R.; Carlucci, T.; Carrasco, J. M.; Casamiquela, L.; Castellani, M.;
Castro-Ginard, A.; Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza,
G.; Costigan, G.; Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.;
Cuypers, J.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.;
David, M.; de Laverny, P.; de Luise, F.; de March, R.; de Martino,
D.; de Souza, R.; de Torres, A.; Debosscher, J.; Del Pozo, E.; Delbo,
M.; Delgado, A.; Delgado, H. E.; Di Matteo, P.; Diakite, S.; Diener,
C.; Distefano, E.; Dolding, C.; Drazinos, P.; Duran, J.; Edvardsson,
B.; Enke, H.; Eriks! Son, K.; E Squej, P.; Eynard Bontemps, G.;
Fabre, C.; Fabrizio, M.; Faigler, S.; Falcao, A. J.; Farras Casas,
M.; Federici, L.; Fedorets, G.; Fernique, P.; Figueras, F.; Filippi,
F.; Findeisen, K.; Fonti, A.; Fraile, E.; Fraser, M.; Frezouls, B.;
Gai, M.; Galleti, S.; Garabato, D.; Garcia-Sedano, F.; Garofalo,
A.; Garralda, N.; Gavel, A.; Gavras, P.; Gerssen, J.; Geyer, R.;
Giacobbe, P.; Gilmore, G.; Girona, S.; Giuffrida, G.; Glass, F.;
Gomes, M.; Granvik, M.; Gueguen, A.; Guerrier, A.; Guiraud, J.;
Gutierrez-Sanchez, R.; Hofmann, W.; Holland, G.; Huckle, H. E.;
Hypki, A.; Icardi, V.; Janssen, K.; Jevardat de Fombelle, G.; Jonker,
P. G.; Juhasz, A. L.; Julbe, F.; Karampelas, A.; Kewley, A.; Klar,
J.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.; Kontizas,
E.; Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.; Koubsky,
P.; Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
Lindstrom, H. E. P.; Lister, T. A.; ! Livanou, E.; Lobel, A.; Lopez,
M.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant,
J. M.; Marconi, M.; Marinoni, S.; Marschalko, G.; Marshall, D. J.;
Martino, M.; Marton, G.; Mary, N.; Matijevic, G.; Mazeh, T.; Messina,
S.; Michalik, D.; Millar, N. R.; Molina, D.; Molinaro, R.; Molnar,
L.; Montegriffo, P.; Mor, R.; Morbidelli, R.; Morel, T.; Morris, D.;
Mulone, A. F.; Muraveva, T.; Musella, I.; Nelemans, G.; Nicastro, L.;
Noval, L.; O'Mullane, W.; Ordenovic, C.; Ordonez-Blanco, D.; Osborne,
P.; Pagani, C.; Pagano, I.; Pailler, F.; Palacin, H.; Palaversa, L.;
Panahi, A.; Pawlak, M.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.;
Plum, G.; Poggio, E.; Poujoulet, E.; Prsa, A.; Pulone, L.; Racero, E.;
Ragaini, S.; Rambaux, N.; Ramos-Lerate, M.; Regibo, S.; Riclet, F.;
Ripepi, V.; Riva, A.; Rivard, A.; Rixon, G.; Roegiers, T.; Roelens,
M.; Romero-Gomez, M.; Rowell, N.; Royer, F.; Ruiz-Dern, L.; Sadowski,
G.; Sagrista Selles, T.; Sahlmann, J.; Salgado, J.; Salguero, E.;
Sanna, N.; Santana-Ros, T.; Sarasso, M.; Savietto, H.; Schultheis,
M.; Sciacca, E.; Segol !, M.; Segov, Ia J. C.; Segransan, D.; Shih,
I. -C.; Siltala, L.; Silva, A. F.; Smart, R. L.; Smith, K. W.;
Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.;
Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmueller, H.;
Stephenson, C. A.; Stoev, H.; Suess, F. F.; Surdej, J.; Szabados, L.;
Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor, M. B.;
Teixeira, R.; Terrett, D.; Teyssandier, P.; Thuillot, W.; Titarenko,
A.; Torra Clotet, F.; Turon, C.; Ulla, A.; Utrilla, E.; Uzzi,
S.; Vaillant, M.; Valentini, G.; Valette, V.; van Elteren, A.;
van Hemelryck, E.; van Leeuwen, M.; Vaschetto, M.; Vecchiato, A.;
Viala, Y.; Vicente, D.; Vogt, S.; von Essen, C.; Voss, H.; Votruba,
V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Wertz, O.; Wevems, T.;
Wyrzykowski, L.; Yoldas, A.; Zerjal, M.; Ziaeepour, H.; Zorec, J.;
Zschocke, S.; Zucker, S.; Zurbach, C.; Zwitter, T.
2018yCat..36160012G Altcode:
The files contains lists of possible members of each of the objects
(75 globular clusters, 9 dwarf spheroidal galaxies, the Bootes I UFD,
the LMC and SMC). The stars in these lists have been selected and used
to determine the astrometric parameters of the corresponding objects
following either the procedures described in Sec. 2.1 (for the clusters
and dwarfs) or in Sec. 2.2 (for the LMC and SMC). The first column is
the "source_id" as given by Gaia, the ra and declination of the star in
degrees, and its G-band magnitude (known as "phot<SUB>g</SUB>mean_mag"
in the Gaia archive). <P />(2 data files).
---------------------------------------------------------
Title: TOPoS. IV. Chemical abundances from high-resolution
observations of seven extremely metal-poor stars
Authors: Bonifacio, P.; Caffau, E.; Spite, M.; Spite, F.; Sbordone,
L.; Monaco, L.; François, P.; Plez, B.; Molaro, P.; Gallagher, A. J.;
Cayrel, R.; Christlieb, N.; Klessen, R. S.; Koch, A.; Ludwig, H. -G.;
Steffen, M.; Zaggia, S.; Abate, C.
2018A&A...612A..65B Altcode: 2018arXiv180103935B
Context. Extremely metal-poor (EMP) stars provide us with indirect
information on the first generations of massive stars. The TOPoS
survey has been designed to increase the census of these stars and to
provide a chemical inventory that is as detailed as possible. <BR />
Aims: Seven of the most iron-poor stars have been observed with the
UVES spectrograph at the ESO VLT Kueyen 8.2 m telescope to refine
their chemical composition. <BR /> Methods: We analysed the spectra
based on 1D LTE model atmospheres, but also used 3D hydrodynamical
simulations of stellar atmospheres. <BR /> Results: We measured carbon
in six of the seven stars: all are carbon-enhanced and belong to the
low-carbon band, defined in the TOPoS II paper. We measured lithium
(A(Li) = 1.9) in the most iron-poor star (SDSS J1035+0641, [Fe/H]
<-5.2). We were also able to measure Li in three stars at [Fe/H]
-4.0, two of which lie on the Spite plateau. We confirm that SDSS
J1349+1407 is extremely rich in Mg, but not in Ca. It is also very
rich in Na. Several of our stars are characterised by low α-to-iron
ratios. <BR /> Conclusions: The lack of high-carbon band stars at low
metallicity can be understood in terms of evolutionary timescales
of binary systems. The detection of Li in SDSS J1035+0641 places a
strong constraint on theories that aim at solving the cosmological
lithium problem. The Li abundance of the two warmer stars at [Fe/H]
-4.0 places them on the Spite plateau, while the third, cooler star,
lies below. We argue that this suggests that the temperature at which
Li depletion begins increases with decreasing [Fe/H]. SDSS J1349+1407
may belong to a class of Mg-rich EMP stars. We cannot assess if there
is a scatter in α-to-iron ratios among the EMP stars or if there are
several discrete populations. However, the existence of stars with
low α-to-iron ratios is supported by our observations. <P />Based
on observations obtained at ESO Paranal Observatory, Programmes
189.D-0165,090.D-0306, 093.D-0136, and 096.D-0468.
---------------------------------------------------------
Title: Abundance patterns of the light neutron-capture elements in
very and extremely metal-poor stars
Authors: Spite, F.; Spite, M.; Barbuy, B.; Bonifacio, P.; Caffau,
E.; François, P.
2018A&A...611A..30S Altcode: 2018arXiv180101304S
<BR /> Aims: The abundance patterns of the neutron-capture elements
in metal-poor stars provide a unique record of the nucleosynthesis
products of the earlier massive primitive objects. <BR /> Methods:
We measured new abundances of so-called light neutron-capture of first
peak elements using local thermodynamic equilibrium (LTE) 1D analysis;
this analysis resulted in a sample of 11 very metal-poor stars, from
[Fe/H] = -2.5 to [Fe/H] = -3.4, and one carbon-rich star, CS 22949-037
with [Fe/H] = -4.0. The abundances were compared to those observed in
two classical metal-poor stars: the typical r-rich star CS 31082-001
([Eu/Fe] > +1.0) and the r-poor star HD 122563 ([Eu/Fe] < 0.0),
which are known to present a strong enrichment of the first peak
neutron-capture elements relative to the second peak. <BR /> Results:
Within the first peak, the abundances are well correlated in analogy
to the well-known correlation inside the abundances of the second-peak
elements. In contrast, there is no correlation between any first peak
element with any second peak element. We show that the scatter of the
ratio of the first peak abundance over second peak abundance increases
when the mean abundance of the second peak elements decreases from
r-rich to r-poor stars. We found two new r-poor stars that are very
similar to HD 122563. A third r-poor star, CS 22897-008, is even more
extreme; this star shows the most extreme example of first peak elements
enrichment to date. On the contrary, another r-poor star (BD-18 5550)
has a pattern of first peak elements that is similar to the typical
r-rich stars CS 31082-001, however this star has some Mo enrichment. <BR
/> Conclusions: The distribution of the neutron-capture elements in our
very metal-poor stars can be understood as the combination of at least
two mechanisms: one that enriches the forming stars cloud homogeneously
through the main r-process and leads to an element pattern similar to
the r-rich stars, such as CS 31082-001; and another that forms mainly
lighter, first peak elements. <P />Based on observations collected at
the European Organisation for Astronomical Research in the Southern
Hemisphere under ESO programme 165.N-0276(A), (PI R.Cayrel).
---------------------------------------------------------
Title: Ages and Heavy Element Abundances from Very Metal-poor Stars
in the Sagittarius Dwarf Galaxy
Authors: Hansen, Camilla Juul; El-Souri, Mariam; Monaco, Lorenzo;
Villanova, Sandro; Bonifacio, Piercarlo; Caffau, Elisabetta; Sbordone,
Luca
2018ApJ...855...83H Altcode: 2017arXiv171102101H
Sagittarius (Sgr) is a massive disrupted dwarf spheroidal galaxy in the
Milky Way halo that has undergone several stripping events. Previous
chemical studies were restricted mainly to a few, metal-rich ([Fe/H]
\gtrapprox -1) stars that suggested a top-light initial mass function
(IMF). Here we present the first high-resolution, very metal-poor
([Fe/H] =-1 to -3) sample of 13 giant stars in the main body of Sgr. We
derive abundances of 13 elements, namely C, Ca, Co, Fe, Sr, Ba, La,
Ce, Nd, Eu, Dy, Pb, and Th, that challenge the interpretation based on
previous studies. Our abundances from Sgr mimic those of the metal-poor
halo, and our most metal-poor star ([Fe/H] ∼ -3) indicates a pure
r-process pollution. Abundances of Sr, Pb, and Th are presented for
the first time in Sgr, allowing for age determination using nuclear
cosmochronology. We calculate ages of 9+/- 2.5 {Gyr}. Most of the
sample stars have been enriched by a range of asymptotic giant branch
(AGB) stars with masses between 1.3 and 5 M <SUB>⊙</SUB>. Sgr
J190651.47-320147.23 shows a large overabundance of Pb (2.05 dex)
and a peculiar abundance pattern best fit by a 3 M <SUB>⊙</SUB> AGB
star. Based on star-to-star scatter and observed abundance patterns,
a mixture of low- and high-mass AGB stars and supernovae (15-25 M
<SUB>⊙</SUB>) is necessary to explain these patterns. The high level
(0.29 ± 0.05 dex) of Ca indicates that massive supernovae must have
existed and polluted the early ISM of Sgr before it lost its gas. This
result is in contrast with a top-light IMF with no massive stars
polluting Sgr. <P />Based on data obtained UVES/VLT ID: 083.B-0774,
075.B-0127.
---------------------------------------------------------
Title: Using the CIFIST grid of CO<SUP>5</SUP>BOLD 3D model
atmospheres to study the effects of stellar granulation on photometric
colours. I. Grids of 3D corrections in the UBVRI, 2MASS, HIPPARCOS,
Gaia, and SDSS systems
Authors: Bonifacio, P.; Caffau, E.; Ludwig, H. -G.; Steffen, M.;
Castelli, F.; Gallagher, A. J.; Kučinskas, A.; Prakapavičius, D.;
Cayrel, R.; Freytag, B.; Plez, B.; Homeier, D.
2018A&A...611A..68B Altcode: 2017arXiv171200024B
Context. The atmospheres of cool stars are temporally and spatially
inhomogeneous due to the effects of convection. The influence of
this inhomogeneity, referred to as granulation, on colours has never
been investigated over a large range of effective temperatures and
gravities. Aim. We aim to study, in a quantitative way, the impact of
granulation on colours. <BR /> Methods: We use the CIFIST (Cosmological
Impact of the FIrst Stars) grid of CO5BOLD (COnservative COde for the
COmputation of COmpressible COnvection in a BOx of L Dimensions, L = 2,
3) hydrodynamical models to compute emerging fluxes. These in turn are
used to compute theoretical colours in the UBV RI, 2MASS, HIPPARCOS,
Gaia and SDSS systems. Every CO5BOLD model has a corresponding one
dimensional (1D) plane-parallel LHD (Lagrangian HydroDynamics) model
computed for the same atmospheric parameters, which we used to define
a "3D correction" that can be applied to colours computed from fluxes
computed from any 1D model atmosphere code. As an example, we illustrate
these corrections applied to colours computed from ATLAS models. <BR />
Results: The 3D corrections on colours are generally small, of the order
of a few hundredths of a magnitude, yet they are far from negligible. We
find that ignoring granulation effects can lead to underestimation of
Teff by up to 200 K and overestimation of gravity by up to 0.5 dex, when
using colours as diagnostics. We have identified a major shortcoming in
how scattering is treated in the current version of the CIFIST grid,
which could lead to offsets of the order 0.01 mag, especially for
colours involving blue and UV bands. We have investigated the Gaia and
HIPPARCOS photometric systems and found that the (G - H<SUB>p</SUB>),
(BP - RP) diagram is immune to the effects of granulation. In addition,
we point to the potential of the RVS photometry as a metallicity
diagnostic. <BR /> Conclusions: Our investigation shows that the
effects of granulation should not be neglected if one wants to use
colours as diagnostics of the stellar parameters of F, G, K stars. A
limitation is that scattering is treated as true absorption in our
current computations, thus our 3D corrections are likely an upper
limit to the true effect. We are already computing the next generation
of the CIFIST grid, using an approximate treatment of scattering. <P
/>The appendix tables are only available at the CDS via anonymous ftp
to <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(<A href="http://cdsarc.u-strasbg.fr">http://130.79.128.5</A>) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/611/A68">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/611/A68</A>
---------------------------------------------------------
Title: VizieR Online Data Catalog: 3D correction in 5 photometric
systems (Bonifacio+, 2018)
Authors: Bonifacio, P.; Caffau, E.; Ludwig, H. -G.; Steffen, M.;
Castelli, F.; Gallagher, A. J.; Kucinskas, A.; Prakapavicius, D.;
Cayrel, R.; Freytag, B.; Plez, B.; Homeier, D.
2018yCat..36110068B Altcode:
We have used the CIFIST grid of CO5BOLD models to investigate the
effects of granulation on fluxes and colours of stars of spectral
type F, G, and K. <P />We publish tables with 3D corrections that
can be applied to colours computed from any 1D model atmosphere. For
Teff>=5000K, the corrections are smooth enough, as a function
of atmospheric parameters, that it is possible to interpolate the
corrections between grid points; thus the coarseness of the CIFIST
grid should not be a major limitation. However at the cool end there
are still far too few models to allow a reliable interpolation. <P
/>(20 data files).
---------------------------------------------------------
Title: Galactic evolution of copper in the light of NLTE computations
Authors: Andrievsky, S.; Bonifacio, P.; Caffau, E.; Korotin, S.;
Spite, M.; Spite, F.; Sbordone, L.; Zhukova, A. V.
2018MNRAS.473.3377A Altcode: 2017arXiv170908619A
We have developed a model atom for Cu with which we perform statistical
equilibrium computations that allow us to compute the line formation of
Cu I lines in stellar atmospheres without assuming local thermodynamic
equilibrium (LTE). We validate this model atom by reproducing the
observed line profiles of the Sun, Procyon and 11 metal-poor stars. Our
sample of stars includes both dwarfs and giants. Over a wide range of
stellar parameters, we obtain excellent agreement among different Cu
I lines. The 11 metal-poor stars have iron abundances in the range -
4.2 ≤ [Fe/H] ≤ -1.4, the weighted mean of the [Cu/Fe] ratios is
-0.22 dex, with a scatter of -0.15 dex. This is very different from
the results from LTE analysis (the difference between NLTE and LTE
abundances reaches 1 dex) and in spite of the small size of our sample,
it prompts for a revision of the Galactic evolution of Cu.
---------------------------------------------------------
Title: The Pristine survey - I. Mining the Galaxy for the most
metal-poor stars
Authors: Starkenburg, Else; Martin, Nicolas; Youakim, Kris; Aguado,
David S.; Allende Prieto, Carlos; Arentsen, Anke; Bernard, Edouard
J.; Bonifacio, Piercarlo; Caffau, Elisabetta; Carlberg, Raymond G.;
Côté, Patrick; Fouesneau, Morgan; François, Patrick; Franke,
Oliver; González Hernández, Jonay I.; Gwyn, Stephen D. J.; Hill,
Vanessa; Ibata, Rodrigo A.; Jablonka, Pascale; Longeard, Nicolas;
McConnachie, Alan W.; Navarro, Julio F.; Sánchez-Janssen, Rubén;
Tolstoy, Eline; Venn, Kim A.
2017MNRAS.471.2587S Altcode: 2017arXiv170501113S
We present the Pristine survey, a new narrow-band photometric survey
focused on the metallicity-sensitive Ca H&K lines and conducted
in the Northern hemisphere with the wide-field imager MegaCam on
the Canada-France-Hawaii Telescope. This paper reviews our overall
survey strategy and discusses the data processing and metallicity
calibration. Additionally we review the application of these data to
the main aims of the survey, which are to gather a large sample of
the most metal-poor stars in the Galaxy, to further characterize the
faintest Milky Way satellites, and to map the (metal-poor) substructure
in the Galactic halo. The current Pristine footprint comprises over
1000 deg<SUP>2</SUP> in the Galactic halo ranging from b ∼ 30° to
∼78° and covers many known stellar substructures. We demonstrate
that, for Sloan Digital Sky Survey (SDSS) stellar objects, we can
calibrate the photometry at the 0.02-mag level. The comparison with
existing spectroscopic metallicities from SDSS/Sloan Extension for
Galactic Understanding and Exploration (SEGUE) and Large Sky Area
Multi-Object Fiber Spectroscopic Telescope shows that, when combined
with SDSS broad-band g and I photometry, we can use the CaHK photometry
to infer photometric metallicities with an accuracy of ∼0.2 dex from
[Fe/H] = -0.5 down to the extremely metal-poor regime ([Fe/H] <
-3.0). After the removal of various contaminants, we can efficiently
select metal-poor stars and build a very complete sample with high
purity. The success rate of uncovering [Fe/H]<SUB>SEGUE</SUB> <
-3.0 stars among [Fe/H]<SUB>Pristine</SUB> < -3.0 selected stars
is 24 per cent, and 85 per cent of the remaining candidates are still
very metal poor ([Fe/H]<-2.0). We further demonstrate that Pristine
is well suited to identify the very rare and pristine Galactic stars
with [Fe/H] < -4.0, which can teach us valuable lessons about the
early Universe.
---------------------------------------------------------
Title: The Canada-France Imaging Survey: First Results from the
u-Band Component
Authors: Ibata, Rodrigo A.; McConnachie, Alan; Cuillandre,
Jean-Charles; Fantin, Nicholas; Haywood, Misha; Martin, Nicolas F.;
Bergeron, Pierre; Beckmann, Volker; Bernard, Edouard; Bonifacio,
Piercarlo; Caffau, Elisabetta; Carlberg, Raymond; Côté, Patrick;
Cabanac, Rémi; Chapman, Scott; Duc, Pierre-Alain; Durret, Florence;
Famaey, Benoît; Fabbro, Sébastien; Gwyn, Stephen; Hammer, Francois;
Hill, Vanessa; Hudson, Michael J.; Lançon, Ariane; Lewis, Geraint;
Malhan, Khyati; di Matteo, Paola; McCracken, Henry; Mei, Simona;
Mellier, Yannick; Navarro, Julio; Pires, Sandrine; Pritchet, Chris;
Reylé, Celine; Richer, Harvey; Robin, Annie C.; Sánchez-Janssen,
Rubén; Sawicki, Marcin; Scott, Douglas; Scottez, Vivien; Spekkens,
Kristine; Starkenburg, Else; Thomas, Guillaume; Venn, Kim
2017ApJ...848..128I Altcode: 2017arXiv170806356I
The Canada-France Imaging Survey (CFIS) will map the northern high
Galactic latitude sky in the u-band ("CFIS-u," 10,000 °<SUP>2</SUP>)
and in the r-band ("CFIS-r," 5000 °<SUP>2</SUP>), enabling a host
of stand-alone science investigations, and providing some of the
ground-based data necessary for photometric redshift determination for
the Euclid mission. In this first contribution, we present the u-band
component of the survey, describe the observational strategy, and
discuss some first highlight results, based on approximately one-third
of the final area. We show that the Galactic anticenter structure is
distributed continuously along the line of sight, out to beyond 20 kpc,
and possesses a metallicity distribution that is essentially identical
to that of the outer disk sampled by APOGEE. This suggests that it
is probably a buckled disk of old metal-rich stars, rather than a
stream or a flare. We also discuss the future potential for CFIS-u
in discovering star-forming dwarf galaxies around the Local Group,
the characterization of the white dwarf and blue straggler population
of the Milky Way, as well as its sensitivity to low surface brightness
structures in external galaxies.
---------------------------------------------------------
Title: Chemical Mapping of the Milky Way with The Canada-France
Imaging Survey: A Non-parametric Metallicity-Distance Decomposition
of the Galaxy
Authors: Ibata, Rodrigo A.; McConnachie, Alan; Cuillandre,
Jean-Charles; Fantin, Nicholas; Haywood, Misha; Martin, Nicolas F.;
Bergeron, Pierre; Beckmann, Volker; Bernard, Edouard; Bonifacio,
Piercarlo; Caffau, Elisabetta; Carlberg, Raymond; Côté, Patrick;
Cabanac, Rémi; Chapman, Scott; Duc, Pierre-Alain; Durret, Florence;
Famaey, Benoît; Fabbro, Sébastien; Gwyn, Stephen; Hammer, Francois;
Hill, Vanessa; Hudson, Michael J.; Lançon, Ariane; Lewis, Geraint;
Malhan, Khyati; di Matteo, Paola; McCracken, Henry; Mei, Simona;
Mellier, Yannick; Navarro, Julio; Pires, Sandrine; Pritchet, Chris;
Reylé, Celine; Richer, Harvey; Robin, Annie C.; Sánchez-Janssen,
Rubén; Sawicki, Marcin; Scott, Douglas; Scottez, Vivien; Spekkens,
Kristine; Starkenburg, Else; Thomas, Guillaume; Venn, Kim
2017ApJ...848..129I Altcode: 2017arXiv170806359I
We present the chemical distribution of the Milky Way, based on
2900 {\deg }<SUP>2</SUP> of u-band photometry taken as part of
the Canada-France Imaging Survey. When complete, this survey will
cover 10,000 {\deg }<SUP>2</SUP> of the northern sky. By combing the
CFHT u-band photometry together with Sloan Digital Sky Survey and
Pan-STARRS g,r, and I, we demonstrate that we are able to reliably
measure the metallicities of individual stars to ∼0.2 dex, and
hence additionally obtain good photometric distance estimates. This
survey thus permits the measurement of metallicities and distances
of the dominant main-sequence (MS) population out to approximately 30
{kpc}, and provides a much higher number of stars at large extraplanar
distances than have been available from previous surveys. We develop a
non-parametric distance-metallicity decomposition algorithm and apply
it to the sky at 30^\circ < | b| < 70^\circ and to the North
Galactic Cap. We find that the metallicity-distance distribution is
well-represented by three populations whose metallicity distributions
do not vary significantly with vertical height above the disk. As
traced in MS stars, the stellar halo component shows a vertical density
profile that is close to exponential, with a scale height of around
3 {kpc}. This may indicate that the inner halo was formed partly from
disk stars ejected in an ancient minor merger.
---------------------------------------------------------
Title: Gaia Data Release 1. Testing parallaxes with local Cepheids
and RR Lyrae stars
Authors: Gaia Collaboration; Clementini, G.; Eyer, L.; Ripepi, V.;
Marconi, M.; Muraveva, T.; Garofalo, A.; Sarro, L. M.; Palmer, M.;
Luri, X.; Molinaro, R.; Rimoldini, L.; Szabados, L.; Musella, I.;
Anderson, R. I.; Prusti, T.; de Bruijne, J. H. J.; Brown, A. G. A.;
Vallenari, A.; Babusiaux, C.; Bailer-Jones, C. A. L.; Bastian, U.;
Biermann, M.; Evans, D. W.; Jansen, F.; Jordi, C.; Klioner, S. A.;
Lammers, U.; Lindegren, L.; Mignard, F.; Panem, C.; Pourbaix,
D.; Randich, S.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.;
Valette, V.; van Leeuwen, F.; Walton, N. A.; Aerts, C.; Arenou,
F.; Cropper, M.; Drimmel, R.; Høg, E.; Katz, D.; Lattanzi, M. G.;
O'Mullane, W.; Grebel, E. K.; Holland, A. D.; Huc, C.; Passot,
X.; Perryman, M.; Bramante, L.; Cacciari, C.; Castañeda, J.;
Chaoul, L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.;
Hernández, J.; Jean-Antoine-Piccolo, A.; Masana, E.; Messineo,
R.; Mowlavi, N.; Nienartowicz, K.; Ordóñez-Blanco, D.; Panuzzo,
P.; Portell, J.; Richards, P. J.; Riello, M.; Seabroke, G. M.;
Tanga, P.; Thévenin, F.; Torra, J.; Els, S. G.; Gracia-Abril, G.;
Comoretto, G.; Garcia-Reinaldos, M.; Lock, T.; Mercier, E.; Altmann,
M.; Andrae, R.; Astraatmadja, T. L.; Bellas-Velidis, I.; Benson,
K.; Berthier, J.; Blomme, R.; Busso, G.; Carry, B.; Cellino, A.;
Cowell, S.; Creevey, O.; Cuypers, J.; Davidson, M.; De Ridder, J.;
de Torres, A.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.; Frémat,
Y.; García-Torres, M.; Gosset, E.; Halbwachs, J. -L.; Hambly, N. C.;
Harrison, D. L.; Hauser, M.; Hestroffer, D.; Hodgkin, S. T.; Huckle,
H. E.; Hutton, A.; Jasniewicz, G.; Jordan, S.; Kontizas, M.; Korn,
A. J.; Lanzafame, A. C.; Manteiga, M.; Moitinho, A.; Muinonen, K.;
Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J. -M.; Recio-Blanco,
A.; Robin, A. C.; Siopis, C.; Smith, M.; Smith, K. W.; Sozzetti, A.;
Thuillot, W.; van Reeven, W.; Viala, Y.; Abbas, U.; Abreu Aramburu,
A.; Accart, S.; Aguado, J. J.; Allan, P. M.; Allasia, W.; Altavilla,
G.; Álvarez, M. A.; Alves, J.; Andrei, A. H.; Anglada Varela, E.;
Antiche, E.; Antoja, T.; Antón, S.; Arcay, B.; Bach, N.; Baker,
S. G.; Balaguer-Núñez, L.; Barache, C.; Barata, C.; Barbier, A.;
Barblan, F.; Barrado y Navascués, D.; Barros, M.; Barstow, M. A.;
Becciani, U.; Bellazzini, M.; Bello García, A.; Belokurov, V.;
Bendjoya, P.; Berihuete, A.; Bianchi, L.; Bienaymé, O.; Billebaud,
F.; Blagorodnova, N.; Blanco-Cuaresma, S.; Boch, T.; Bombrun, A.;
Borrachero, R.; Bouquillon, S.; Bourda, G.; Bragaglia, A.; Breddels,
M. A.; Brouillet, N.; Brüsemeister, T.; Bucciarelli, B.; Burgess,
P.; Burgon, R.; Burlacu, A.; Busonero, D.; Buzzi, R.; Caffau,
E.; Cambras, J.; Campbell, H.; Cancelliere, R.; Cantat-Gaudin, T.;
Carlucci, T.; Carrasco, J. M.; Castellani, M.; Charlot, P.; Charnas,
J.; Chiavassa, A.; Clotet, M.; Cocozza, G.; Collins, R. S.; Costigan,
G.; Crifo, F.; Cross, N. J. G.; Crosta, M.; Crowley, C.; Dafonte,
C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; De Cat, P.;
de Felice, F.; de Laverny, P.; De Luise, F.; De March, R.; de Souza,
R.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.; Delgado,
H. E.; Di Matteo, P.; Diakite, S.; Distefano, E.; Dolding, C.; Dos
Anjos, S.; Drazinos, P.; Durán, J.; Dzigan, Y.; Edvardsson, B.;
Enke, H.; Evans, N. W.; Eynard Bontemps, G.; Fabre, C.; Fabrizio,
M.; Falcão, A. J.; Farràs Casas, M.; Federici, L.; Fedorets,
G.; Fernández-Hernández, J.; Fernique, P.; Fienga, A.; Figueras,
F.; Filippi, F.; Findeisen, K.; Fonti, A.; Fouesneau, M.; Fraile,
E.; Fraser, M.; Fuchs, J.; Gai, M.; Galleti, S.; Galluccio, L.;
Garabato, D.; García-Sedano, F.; Garralda, N.; Gavras, P.; Gerssen,
J.; Geyer, R.; Gilmore, G.; Girona, S.; Giuffrida, G.; Gomes, M.;
González-Marcos, A.; González-Núñez, J.; González-Vidal, J. J.;
Granvik, M.; Guerrier, A.; Guillout, P.; Guiraud, J.; Gúrpide, A.;
Gutiérrez-Sánchez, R.; Guy, L. P.; Haigron, R.; Hatzidimitriou, D.;
Haywood, M.; Heiter, U.; Helmi, A.; Hobbs, D.; Hofmann, W.; Holl, B.;
Holland, G.; Hunt, J. A. S.; Hypki, A.; Icardi, V.; Irwin, M.; Jevardat
de Fombelle, G.; Jofré, P.; Jonker, P. G.; Jorissen, A.; Julbe, F.;
Karampelas, A.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas,
E.; Koposov, S. E.; Kordopatis, G.; Koubsky, P.; Krone-Martins, A.;
Kudryashova, M.; Bachchan, R. K.; Lacoste-Seris, F.; Lanza, A. F.;
Lavigne, J. -B.; Le Poncin-Lafitte, C.; Lebreton, Y.; Lebzelter, T.;
Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Lemaitre, V.; Lenhardt,
H.; Leroux, F.; Liao, S.; Licata, E.; Lindstrøm, H. E. P.; Lister,
T. A.; Livanou, E.; Lobel, A.; Löffler, W.; López, M.; Lorenz, D.;
MacDonald, I.; Magalhães Fernandes, T.; Managau, S.; Mann, R. G.;
Mantelet, G.; Marchal, O.; Marchant, J. M.; Marinoni, S.; Marrese,
P. M.; Marschalkó, G.; Marshall, D. J.; Martín-Fleitas, J. M.;
Martino, M.; Mary, N.; Matijevič, G.; McMillan, P. J.; Messina,
S.; Michalik, D.; Millar, N. R.; Miranda, B. M. H.; Molina, D.;
Molinaro, M.; Molnár, L.; Moniez, M.; Montegriffo, P.; Mor, R.;
Mora, A.; Morbidelli, R.; Morel, T.; Morgenthaler, S.; Morris, D.;
Mulone, A. F.; Narbonne, J.; Nelemans, G.; Nicastro, L.; Noval, L.;
Ordénovic, C.; Ordieres-Meré, J.; Osborne, P.; Pagani, C.; Pagano,
I.; Pailler, F.; Palacin, H.; Palaversa, L.; Parsons, P.; Pecoraro,
M.; Pedrosa, R.; Pentikäinen, H.; Pichon, B.; Piersimoni, A. M.;
Pineau, F. -X.; Plachy, E.; Plum, G.; Poujoulet, E.; Prša, A.;
Pulone, L.; Ragaini, S.; Rago, S.; Rambaux, N.; Ramos-Lerate, M.;
Ranalli, P.; Rauw, G.; Read, A.; Regibo, S.; Reylé, C.; Ribeiro,
R. A.; Riva, A.; Rixon, G.; Roelens, M.; Romero-Gómez, M.; Rowell,
N.; Royer, F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.;
Sahlmann, J.; Salgado, J.; Salguero, E.; Sarasso, M.; Savietto, H.;
Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Segransan,
D.; Shih, I. -C.; Smareglia, R.; Smart, R. L.; Solano, E.; Solitro,
F.; Sordo, R.; Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.;
Stampa, U.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.;
Stoev, H.; Suess, F. F.; Süveges, M.; Surdej, J.; Szegedi-Elek, E.;
Tapiador, D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.;
Terrett, D.; Tingley, B.; Trager, S. C.; Turon, C.; Ulla, A.; Utrilla,
E.; Valentini, G.; van Elteren, A.; Van Hemelryck, E.; van Leeuwen, M.;
Varadi, M.; Vecchiato, A.; Veljanoski, J.; Via, T.; Vicente, D.; Vogt,
S.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.;
Weingrill, K.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.;
Zucker, S.; Zurbach, C.; Zwitter, T.; Alecu, A.; Allen, M.; Allende
Prieto, C.; Amorim, A.; Anglada-Escudé, G.; Arsenijevic, V.; Azaz,
S.; Balm, P.; Beck, M.; Bernstein, H. -H.; Bigot, L.; Bijaoui, A.;
Blasco, C.; Bonfigli, M.; Bono, G.; Boudreault, S.; Bressan, A.;
Brown, S.; Brunet, P. -M.; Bunclark, P.; Buonanno, R.; Butkevich,
A. G.; Carret, C.; Carrion, C.; Chemin, L.; Chéreau, F.; Corcione,
L.; Darmigny, E.; de Boer, K. S.; de Teodoro, P.; de Zeeuw, P. T.;
Delle Luche, C.; Domingues, C. D.; Dubath, P.; Fodor, F.; Frézouls,
B.; Fries, A.; Fustes, D.; Fyfe, D.; Gallardo, E.; Gallegos, J.;
Gardiol, D.; Gebran, M.; Gomboc, A.; Gómez, A.; Grux, E.; Gueguen,
A.; Heyrovsky, A.; Hoar, J.; Iannicola, G.; Isasi Parache, Y.;
Janotto, A. -M.; Joliet, E.; Jonckheere, A.; Keil, R.; Kim, D. -W.;
Klagyivik, P.; Klar, J.; Knude, J.; Kochukhov, O.; Kolka, I.; Kos,
J.; Kutka, A.; Lainey, V.; LeBouquin, D.; Liu, C.; Loreggia, D.;
Makarov, V. V.; Marseille, M. G.; Martayan, C.; Martinez-Rubi, O.;
Massart, B.; Meynadier, F.; Mignot, S.; Munari, U.; Nguyen, A. -T.;
Nordlander, T.; O'Flaherty, K. S.; Ocvirk, P.; Olias Sanz, A.; Ortiz,
P.; Osorio, J.; Oszkiewicz, D.; Ouzounis, A.; Park, P.; Pasquato, E.;
Peltzer, C.; Peralta, J.; Péturaud, F.; Pieniluoma, T.; Pigozzi, E.;
Poels, J.; Prat, G.; Prod'homme, T.; Raison, F.; Rebordao, J. M.;
Risquez, D.; Rocca-Volmerange, B.; Rosen, S.; Ruiz-Fuertes, M. I.;
Russo, F.; Serraller Vizcaino, I.; Short, A.; Siebert, A.; Silva, H.;
Sinachopoulos, D.; Slezak, E.; Soffel, M.; Sosnowska, D.; Straižys,
V.; ter Linden, M.; Terrell, D.; Theil, S.; Tiede, C.; Troisi, L.;
Tsalmantza, P.; Tur, D.; Vaccari, M.; Vachier, F.; Valles, P.; Van
Hamme, W.; Veltz, L.; Virtanen, J.; Wallut, J. -M.; Wichmann, R.;
Wilkinson, M. I.; Ziaeepour, H.; Zschocke, S.
2017A&A...605A..79G Altcode: 2017arXiv170500688G; 2017A&A...605A..79.
Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids,
and 364 RR Lyrae stars in common between Gaia and the HIPPARCOS and
Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part
of the Tycho-Gaia Astrometric Solution (TGAS). <BR /> Aims: In order to
test these first parallax measurements of the primary standard candles
of the cosmological distance ladder, which involve astrometry collected
by Gaia during the initial 14 months of science operation, we compared
them with literature estimates and derived new period-luminosity (PL),
period-Wesenheit (PW) relations for classical and Type II Cepheids and
infrared PL, PL-metallicity (PLZ), and optical luminosity-metallicity
(M<SUB>V</SUB>-[Fe/H]) relations for the RR Lyrae stars, with zero
points based on TGAS. <BR /> Methods: Classical Cepheids were carefully
selected in order to discard known or suspected binary systems. The
final sample comprises 102 fundamental mode pulsators with periods
ranging from 1.68 to 51.66 days (of which 33 with σ<SUB>ϖ</SUB>/ϖ<
0.5). The Type II Cepheids include a total of 26 W Virginis and BL
Herculis stars spanning the period range from 1.16 to 30.00 days
(of which only 7 with σ<SUB>ϖ</SUB>/ϖ< 0.5). The RR Lyrae stars
include 200 sources with pulsation period ranging from 0.27 to 0.80
days (of which 112 with σ<SUB>ϖ</SUB>/ϖ< 0.5). The new relations
were computed using multi-band (V,I,J,K<SUB>s</SUB>) photometry
and spectroscopic metal abundances available in the literature, and
by applying three alternative approaches: (i) linear least-squares
fitting of the absolute magnitudes inferred from direct transformation
of the TGAS parallaxes; (ii) adopting astrometry-based luminosities;
and (iii) using a Bayesian fitting approach. The last two methods work
in parallax space where parallaxes are used directly, thus maintaining
symmetrical errors and allowing negative parallaxes to be used. The
TGAS-based PL,PW,PLZ, and M<SUB>V</SUB>- [Fe/H] relations are discussed
by comparing the distance to the Large Magellanic Cloud provided by
different types of pulsating stars and alternative fitting methods. <BR
/> Results: Good agreement is found from direct comparison of the
parallaxes of RR Lyrae stars for which both TGAS and HST measurements
are available. Similarly, very good agreement is found between the
TGAS values and the parallaxes inferred from the absolute magnitudes
of Cepheids and RR Lyrae stars analysed with the Baade-Wesselink
method. TGAS values also compare favourably with the parallaxes inferred
by theoretical model fitting of the multi-band light curves for two
of the three classical Cepheids and one RR Lyrae star, which were
analysed with this technique in our samples. The K-band PL relations
show the significant improvement of the TGAS parallaxes for Cepheids
and RR Lyrae stars with respect to the HIPPARCOS measurements. This
is particularly true for the RR Lyrae stars for which improvement
in quality and statistics is impressive. <BR /> Conclusions: TGAS
parallaxes bring a significant added value to the previous HIPPARCOS
estimates. The relations presented in this paper represent the first
Gaia-calibrated relations and form a work-in-progress milestone report
in the wait for Gaia-only parallaxes of which a first solution will
become available with Gaia Data Release 2 (DR2) in 2018. <P />Full
Tables A.1-A.3 are only available at the CDS via anonymous ftp to
<A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(<A href="http://130.79.128.5">http://130.79.128.5</A>) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/605/A79">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/605/A79</A>
---------------------------------------------------------
Title: Lithium abundance and <SUP>6</SUP>Li/<SUP>7</SUP>Li ratio in
the active giant HD 123351. I. A comparative analysis of 3D and 1D
NLTE line-profile fits
Authors: Mott, A.; Steffen, M.; Caffau, E.; Spada, F.; Strassmeier,
K. G.
2017A&A...604A..44M Altcode: 2017arXiv170406460M
Context. Current three-dimensional (3D) hydrodynamical model
atmospheres together with detailed spectrum synthesis, accounting
for departures from local thermodynamic equilibrium (LTE), permit
to derive reliable atomic and isotopic chemical abundances from
high-resolution stellar spectra. Not much is known about the presence
of the fragile <SUP>6</SUP>Li isotope in evolved solar-metallicity red
giant branch (RGB) stars, not to mention its production in magnetically
active targets like HD 123351. <BR /> Aims: A detailed spectroscopic
investigation of the lithium resonance doublet in HD 123351 in terms
of both abundance and isotopic ratio is presented. From fits of
the observed spectrum, taken at the Canada-France-Hawaii telescope,
with synthetic line profiles based on 1D and 3D model atmospheres,
we seek to estimate the abundance of the <SUP>6</SUP>Li isotope and
to place constraints on its origin. <BR /> Methods: We derive the
lithium abundance A(Li) and the <SUP>6</SUP>Li/<SUP>7</SUP>Li isotopic
ratio by fitting different synthetic spectra to the Li-line region
of a high-resolution CFHT spectrum (R = 120 000, S/N = 400). The
synthetic spectra are computed with four different line lists,
using in parallel 3D hydrodynamical CO<SUP>5</SUP>BOLD and 1D LHD
model atmospheres and treating the line formation of the lithium
components in non-LTE (NLTE). The fitting procedure is repeated with
different assumptions and wavelength ranges to obtain a reasonable
estimate of the involved uncertainties. <BR /> Results: We find A(Li)
= 1.69 ± 0.11 dex and <SUP>6</SUP>Li/<SUP>7</SUP>Li = 8.0 ± 4.4%
in 3D-NLTE, using the line list of Meléndez et al. (2012, A&A,
543, A29), updated with new atomic data for V I, which results in
the best fit of the lithium line profile of HD 123351. Two other line
lists lead to similar results but with inferior fit qualities. <BR />
Conclusions: Our 2σ detection of the <SUP>6</SUP>Li isotope is the
result of a careful statistical analysis and the visual inspection
of each achieved fit. Since the presence of a significant amount of
<SUP>6</SUP>Li in the atmosphere of a cool evolved star is not expected
in the framework of standard stellar evolution theory, non-standard,
external lithium production mechanisms, possibly related to stellar
activity or a recent accretion of rocky material, need to be invoked
to explain the detection of <SUP>6</SUP>Li in HD 123351.
---------------------------------------------------------
Title: The Gaia-ESO Survey: Galactic evolution of sulphur and zinc
Authors: Duffau, S.; Caffau, E.; Sbordone, L.; Bonifacio, P.;
Andrievsky, S.; Korotin, S.; Babusiaux, C.; Salvadori, S.; Monaco, L.;
François, P.; Skúladóttir, Á.; Bragaglia, A.; Donati, P.; Spina,
L.; Gallagher, A. J.; Ludwig, H. -G.; Christlieb, N.; Hansen, C. J.;
Mott, A.; Steffen, M.; Zaggia, S.; Blanco-Cuaresma, S.; Calura, F.;
Friel, E.; Jiménez-Esteban, F. M.; Koch, A.; Magrini, L.; Pancino,
E.; Tang, B.; Tautvaišienė, G.; Vallenari, A.; Hawkins, K.; Gilmore,
G.; Randich, S.; Feltzing, S.; Bensby, T.; Flaccomio, E.; Smiljanic,
R.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Damiani,
F.; Franciosini, E.; Hourihane, A.; Jofré, P.; Lardo, C.; Lewis,
J.; Morbidelli, L.; Sousa, S. G.; Worley, C. C.
2017A&A...604A.128D Altcode: 2017arXiv170402981D
Context. Due to their volatile nature, when sulphur and zinc are
observed in external galaxies, their determined abundances represent
the gas-phase abundances in the interstellar medium. This implies
that they can be used as tracers of the chemical enrichment of matter
in the Universe at high redshift. Comparable observations in stars
are more difficult and, until recently, plagued by small number
statistics. <BR /> Aims: We wish to exploit the Gaia-ESO Survey
(GES) data to study the behaviour of sulphur and zinc abundances
of a large number of Galactic stars, in a homogeneous way. <BR />
Methods: By using the UVES spectra of the GES sample, we are able to
assemble a sample of 1301 Galactic stars, including stars in open and
globular clusters in which both sulphur and zinc were measured. <BR
/> Results: We confirm the results from the literature that sulphur
behaves as an α-element. We find a large scatter in [Zn/Fe] ratios
among giant stars around solar metallicity. The lower ratios are
observed in giant stars at Galactocentric distances less than 7.5
kpc. No such effect is observed among dwarf stars, since they do not
extend to that radius. <BR /> Conclusions: Given the sample selection,
giants and dwarfs are observed at different Galactic locations, and it
is plausible, and compatible with simple calculations, that Zn-poor
giants trace a younger population more polluted by SN Ia yields. It
is necessary to extend observations in order to observe both giants
and dwarfs at the same Galactic location. Further theoretical work on
the evolution of zinc is also necessary. <P />Based on observations
collected at the European Organisation for Astronomical Research in the
Southern Hemisphere under ESO programmes 188.B-3002, 193.B-0936.The full
table of S abundances is only available at the CDS via anonymous ftp
to <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(<A href="http://130.79.128.5">http://130.79.128.5</A>) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/604/A128">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/604/A128</A>
---------------------------------------------------------
Title: An Investigation of the Formation and Line Properties of MgH
in 3D Hydrodynamical Model Stellar Atmospheres
Authors: Thygesen, Anders O.; Kirby, Evan N.; Gallagher, Andrew J.;
Ludwig, Hans-G.; Caffau, Elisabetta; Bonifacio, Piercarlo; Sbordone,
Luca
2017ApJ...843..144T Altcode: 2017arXiv170604218T
Studies of the isotopic composition of magnesium in cool stars have so
far relied upon the use of 1D model atmospheres. Since the isotopic
ratios derived are based on asymmetries of optical MgH lines, it
is important to test the impact from other effects affecting line
asymmetries, like stellar convection. Here, we present a theoretical
investigation of the effects of including self-consistent modeling
of convection. Using spectral syntheses based on 3D hydrodynamical
CO<SUP>5</SUP>BOLD models of dwarfs (4000 K ≲ T <SUB>eff</SUB> ≲
5160 K, 4.0 ≤ {log}g ≤ 4.5, -3.0≤slant [{Fe}/{{H}}]≤slant
-1.0) and giants (T <SUB>eff</SUB> ∼ 4000 K, {log}g = 1.5,
-3.0≤slant [{Fe}/{{H}}]≤slant -1.0), we perform a detailed
analysis comparing 3D and 1D syntheses. We describe the impact on the
formation and behavior of MgH lines from using 3D models, and perform
a qualitative assessment of the systematics introduced by the use of 1D
syntheses. Using 3D model atmospheres significantly affect the strength
of the MgH lines, especially in dwarfs, with 1D syntheses requiring
an abundance correction of up to +0.69 dex, with the largest for our
5000 K models. The corrections are correlated with T <SUB>eff</SUB>
and are also affected by the metallicity. The shape of the strong
<SUP>24</SUP>MgH component in the 3D syntheses is poorly reproduced in
1D. This results in 1D syntheses underestimating <SUP>25</SUP>Mg by
up to ∼5 percentage points and overestimating <SUP>24</SUP>Mg by a
similar amount for dwarfs. This discrepancy increases with decreasing
metallicity. <SUP>26</SUP>Mg is recovered relatively well, with the
largest difference being ∼2 percentage points. The use of 3D for
giants has less impact, due to smaller differences in the atmospheric
structure and a better reproduction of the line shape in 1D.
---------------------------------------------------------
Title: Abundances of Na, Mg, and K in the atmospheres of red giant
branch stars of Galactic globular cluster 47 Tucanae
Authors: Černiauskas, A.; Kučinskas, A.; Klevas, J.; Prakapavičius,
D.; Korotin, S.; Bonifacio, P.; Ludwig, H. -G.; Caffau, E.; Steffen, M.
2017A&A...604A..35C Altcode: 2017arXiv170402751C
<BR /> Aims: We study the abundances of Na, Mg, and K in the atmospheres
of 32 red giant branch (RGB) stars in the Galactic globular cluster
(GGC) 47 Tuc, with the goal to investigate the possible existence of
Na-K and Mg-K correlations/anti-correlations, similar to those that
were recently discovered in two other GGCs, NGC 2419 and 2808. <BR
/> Methods: The abundances of K, Na, and Mg were determined using
high-resolution 2dF/HERMES spectra obtained with the Anglo-Australian
Telescope (AAT). The one-dimensional (1D) NLTE abundance estimates
were obtained using 1D hydrostatic ATLAS9 model atmospheres and
spectral line profiles synthesized with the MULTI package. We also
used three-dimensional (3D) hydrodynamical CO<SUP>5</SUP>BOLD and
1D hydrostatic LHD model atmospheres to compute 3D-1D LTE abundance
corrections, Δ<SUB>3D - 1D LTE</SUB>, for the spectral lines of Na,
Mg, and K used in our study. These abundance corrections were used to
understand the role of convection in the formation of spectral lines,
as well as to estimate the differences in the abundances obtained with
the 3D hydrodynamical and 1D hydrostatic model atmospheres. <BR />
Results: The average element-to-iron abundance ratios and their RMS
variations due to star-to-star abundance spreads determined in our
sample of RGB stars were ⟨ [ Na / Fe ] ⟩ <SUP>1D NLTE</SUP> =
0.42 ± 0.13, ⟨ [ Mg / Fe ] ⟩ <SUP>1D NLTE</SUP> = 0.41 ± 0.11,
and ⟨ [ K / Fe ] ⟩ <SUP>1D NLTE</SUP> = 0.05 ± 0.14. We found no
statistically significant relations between the abundances of the three
elements studied here. Also, there were no abundance trends with the
distance from the cluster center, nor any statistically significant
relations between the abundance/abundance ratios and absolute radial
velocities of individual stars. All these facts suggest the similarity
of K abundance in stars that belong to different generations in 47
Tuc which, in turn, may hint that evolution of K in this particular
cluster was unrelated to the nucleosynthesis of Na and/or Mg.
---------------------------------------------------------
Title: New ultra metal-poor stars from SDSS: follow-up GTC
medium-resolution spectroscopy
Authors: Aguado, D. S.; Allende Prieto, C.; González Hernández,
J. I.; Rebolo, R.; Caffau, E.
2017A&A...604A...9A Altcode: 2017arXiv170604179A
Context. The first generation of stars formed in the Galaxy left behind
the chemical signatures of their nucleosynthesis in the interstellar
medium, visible today in the atmospheres of low-mass stars that formed
afterwards. Sampling the chemistry of those low-mass provides insight
into the first stars. <BR /> Aims: We aim to increase the samples
of stars with extremely low metal abundances, identifying ultra
metal-poor stars from spectra with modest spectral resolution and
signal-to-noise ratio (S/N). Achieving this goal involves deriving
reliable metallicities and carbon abundances from such spectra. <BR
/> Methods: We carry out follow-up observations of faint, V > 19,
metal-poor candidates selected from SDSS spectroscopy and observed
with the Optical System for Imaging and low-Intermediate-Resolution
Integrated Spectroscopy (OSIRIS) at GTC. The SDSS and follow-up
OSIRIS spectra were analyzed using the FERRE code to derive effective
temperatures, surface gravities, metallicities and carbon abundances. In
addition, a well-known extremely metal-poor star has been included in
our sample to calibrate the analysis methodology. <BR /> Results: We
observed and analyzed five metal-poor candidates from modest-quality
SDSS spectra. All stars in our sample have been confirmed as extremely
metal-poor stars, in the [Fe/H] < -3.3 regime. We report the
recognition of J173403+644632, a carbon-enhanced ultra metal-poor dwarf
star with [Fe/H] = -4.3 and [C/Fe] = + 3.1. <P />Based on observations
made with the Gran Telescopio Canarias (GTC), installed in the Spanish
Observatorio del Roque de los Muchachos of the Instituto de Astrofísica
de Canarias, on the island of La Palma. Programme ID GTC2E-16A and
ID GTC65-16B.
---------------------------------------------------------
Title: The Pristine survey II: A sample of bright stars observed
with FEROS
Authors: Caffau, E.; Bonifacio, P.; Starkenburg, E.; Martin, N.;
Youakim, K.; Henden, A. A.; González Hernández, J. I.; Aguado,
D. S.; Allende Prieto, C.; Venn, K.; Jablonka, P.
2017AN....338..686C Altcode: 2017arXiv170510280C
Extremely metal-poor (EMP) stars are old objects formed in the first Gyr
of the Universe. They are rare and, to select them the most successful
strategy has been to build on large and low-resolution spectroscopic
surveys. The combination of narrow- and broad-band photometry provides
a powerful and cheaper alternative to select metal-poor stars. The
ongoing Pristine Survey is adopting this strategy, conducting photometry
with the Canada France Hawaii Telescope MegaCam wide-field imager
and a narrow-band filter centered at 395.2 nm on the Ca II-H and -K
lines. In this paper, we present the results of the spectroscopic
follow-up conducted on a sample of 26 stars at the bright end of the
magnitude range of the Survey (g⩽15), using FEROS at the MPG/ESO
2.2-m telescope (manufactured by Zeiss, Oberkochen, Germany). From our
chemical investigation on the sample, we conclude that this magnitude
range is too bright to use the Sloan Digital Sky Survey (SDSS) gri
bands, which are typically saturated. Instead, the Pristine photometry
can be usefully combined with the AAVSO Photometric All Sky Survey
(APASS) griphotometry to provide reliable metallicity estimates. Data
from FEROS.Funding Information Robert Martin Ayers Sciences Fund,
PICS, Emmy Noether program, NSF, AST-1412587. Spanish Ministry of
Economy and Competitiveness (MINECO);, MINECO RYC-2013-14875, MINECO
AYA2014-56359-P.
---------------------------------------------------------
Title: VizieR Online Data Catalog: S abundances for 1301 stars from
GES (Duffau+, 2017)
Authors: Duffau, S.; Caffau, E.; Sbordone, L.; Bonifacio, P.;
Andrievsky, S.; Korotin, S.; Babusiaux, C.; Salvadori, S.; Monaco,
L.; Francois, P.; Skuladottir, A.; Bragaglia, A.; Donati, P.; Spina,
L.; Gallagher, A. J.; Ludwig, H. -G.; Christlieb, N.; Hansen, C. J.;
Mott, A.; Steffen, M.; Zaggia, S.; Blanco-Cuaresma, S.; Calura, F.;
Friel, E.; Jimenez-Esteban, F. M.; Koch, A.; Magrini, L.; Pancino,
E.; Tang, B.; Tautvaisiene, G.; Vallenari, A.; Hawkins, K.; Gilmore,
G.; Randich, S.; Feltzing, S.; Bensby, T.; Flaccomio, E.; Smiljanic,
R.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Damiani,
F.; Franciosini, E.; Hourihane, A.; Jofre, P.; Lardo, C.; Lewis, J.;
Morbidelli, L.; Sousa, S. G.; Worley, C. C.
2017yCat..36040128D Altcode:
GES internal star identifier (CNAME), Sulphur abundances and NLTE
corrections to the Sulphur abundances for 1301 stars. Sulphur
abundances are expressed in the customary logarithmic form:
A(S)=log_10(N(S)/N(H))+12. The abundances delivered are the LTE
ones. NLTEabundances can be determined by directly summing the NLTE
correction delivered: A(S)<SUB>NLTE = A(S) + NLTE</SUB>C. So that a
negative NLTE correction indicates that the NLTE abundance is lower
than the LTE one. <P />(1 data file).
---------------------------------------------------------
Title: A Grid of NLTE Corrections for Sulphur Lines in Atmospheres
of Cool Stars for the Gaia-ESO Survey
Authors: Korotin, S.; Andrievsky, S.; Caffau, E.; Bonifacio, P.
2017ASPC..510..141K Altcode:
To derive sulfur abundance in a large amount of the stars from Gaia-ESO
survey we calculated grid of theoretical line equivalent widths of
8th multiplet. We show that NLTE effects increase equivalent widths
of the sulfur lines. NLTE corrections for this multiplet are not too
large (about 0.15 dex) in contrast with corrections for other sulfur
multiplets.
---------------------------------------------------------
Title: Gaia Data Release 1. Open cluster astrometry: performance,
limitations, and future prospects
Authors: Gaia Collaboration; van Leeuwen, F.; Vallenari, A.; Jordi,
C.; Lindegren, L.; Bastian, U.; Prusti, T.; de Bruijne, J. H. J.;
Brown, A. G. A.; Babusiaux, C.; Bailer-Jones, C. A. L.; Biermann,
M.; Evans, D. W.; Eyer, L.; Jansen, F.; Klioner, S. A.; Lammers,
U.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.;
Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; Valette, V.; Walton,
N. A.; Aerts, C.; Arenou, F.; Cropper, M.; Drimmel, R.; Høg, E.; Katz,
D.; Lattanzi, M. G.; O'Mullane, W.; Grebel, E. K.; Holland, A. D.; Huc,
C.; Passot, X.; Perryman, M.; Bramante, L.; Cacciari, C.; Castañeda,
J.; Chaoul, L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.;
Hernández, J.; Jean-Antoine-Piccolo, A.; Masana, E.; Messineo, R.;
Mowlavi, N.; Nienartowicz, K.; Ordóñez-Blanco, D.; Panuzzo, P.;
Portell, J.; Richards, P. J.; Riello, M.; Seabroke, G. M.; Tanga, P.;
Thévenin, F.; Torra, J.; Els, S. G.; Gracia-Abril, G.; Comoretto,
G.; Garcia-Reinaldos, M.; Lock, T.; Mercier, E.; Altmann, M.; Andrae,
R.; Astraatmadja, T. L.; Bellas-Velidis, I.; Benson, K.; Berthier,
J.; Blomme, R.; Busso, G.; Carry, B.; Cellino, A.; Clementini, G.;
Cowell, S.; Creevey, O.; Cuypers, J.; Davidson, M.; De Ridder, J.;
de Torres, A.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.; Frémat,
Y.; García-Torres, M.; Gosset, E.; Halbwachs, J. -L.; Hambly, N. C.;
Harrison, D. L.; Hauser, M.; Hestroffer, D.; Hodgkin, S. T.; Huckle,
H. E.; Hutton, A.; Jasniewicz, G.; Jordan, S.; Kontizas, M.; Korn,
A. J.; Lanzafame, A. C.; Manteiga, M.; Moitinho, A.; Muinonen, K.;
Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J. -M.; Recio-Blanco,
A.; Robin, A. C.; Sarro, L. M.; Siopis, C.; Smith, M.; Smith, K. W.;
Sozzetti, A.; Thuillot, W.; van Reeven, W.; Viala, Y.; Abbas, U.;
Abreu Aramburu, A.; Accart, S.; Aguado, J. J.; Allan, P. M.; Allasia,
W.; Altavilla, G.; Álvarez, M. A.; Alves, J.; Anderson, R. I.; Andrei,
A. H.; Anglada Varela, E.; Antiche, E.; Antoja, T.; Antón, S.; Arcay,
B.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.; Barache, C.; Barata,
C.; Barbier, A.; Barblan, F.; Barrado y Navascués, D.; Barros, M.;
Barstow, M. A.; Becciani, U.; Bellazzini, M.; Bello García, A.;
Belokurov, V.; Bendjoya, P.; Berihuete, A.; Bianchi, L.; Bienaymé,
O.; Billebaud, F.; Blagorodnova, N.; Blanco-Cuaresma, S.; Boch, T.;
Bombrun, A.; Borrachero, R.; Bouquillon, S.; Bourda, G.; Bouy, H.;
Bragaglia, A.; Breddels, M. A.; Brouillet, N.; Brüsemeister, T.;
Bucciarelli, B.; Burgess, P.; Burgon, R.; Burlacu, A.; Busonero, D.;
Buzzi, R.; Caffau, E.; Cambras, J.; Campbell, H.; Cancelliere, R.;
Cantat-Gaudin, T.; Carlucci, T.; Carrasco, J. M.; Castellani, M.;
Charlot, P.; Charnas, J.; Chiavassa, A.; Clotet, M.; Cocozza, G.;
Collins, R. S.; Costigan, G.; Crifo, F.; Cross, N. J. G.; Crosta, M.;
Crowley, C.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.;
David, M.; De Cat, P.; de Felice, F.; de Laverny, P.; De Luise, F.;
De March, R.; de Martino, D.; de Souza, R.; Debosscher, J.; del Pozo,
E.; Delbo, M.; Delgado, A.; Delgado, H. E.; Di Matteo, P.; Diakite, S.;
Distefano, E.; Dolding, C.; Dos Anjos, S.; Drazinos, P.; Durán, J.;
Dzigan, Y.; Edvardsson, B.; Enke, H.; Evans, N. W.; Eynard Bontemps,
G.; Fabre, C.; Fabrizio, M.; Faigler, S.; Falcão, A. J.; Farràs
Casas, M.; Federici, L.; Fedorets, G.; Fernández-Hernández, J.;
Fernique, P.; Fienga, A.; Figueras, F.; Filippi, F.; Findeisen, K.;
Fonti, A.; Fouesneau, M.; Fraile, E.; Fraser, M.; Fuchs, J.; Gai, M.;
Galleti, S.; Galluccio, L.; Garabato, D.; García-Sedano, F.; Garofalo,
A.; Garralda, N.; Gavras, P.; Gerssen, J.; Geyer, R.; Gilmore,
G.; Girona, S.; Giuffrida, G.; Gomes, M.; González-Marcos, A.;
González-Núñez, J.; González-Vidal, J. J.; Granvik, M.; Guerrier,
A.; Guillout, P.; Guiraud, J.; Gúrpide, A.; Gutiérrez-Sánchez,
R.; Guy, L. P.; Haigron, R.; Hatzidimitriou, D.; Haywood, M.; Heiter,
U.; Helmi, A.; Hobbs, D.; Hofmann, W.; Holl, B.; Holland, G.; Hunt,
J. A. S.; Hypki, A.; Icardi, V.; Irwin, M.; Jevardat de Fombelle,
G.; Jofré, P.; Jonker, P. G.; Jorissen, A.; Julbe, F.; Karampelas,
A.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, E.; Koposov,
S. E.; Kordopatis, G.; Koubsky, P.; Krone-Martins, A.; Kudryashova, M.;
Kull, I.; Bachchan, R. K.; Lacoste-Seris, F.; Lanza, A. F.; Lavigne,
J. -B.; Le Poncin-Lafitte, C.; Lebreton, Y.; Lebzelter, T.; Leccia, S.;
Leclerc, N.; Lecoeur-Taibi, I.; Lemaitre, V.; Lenhardt, H.; Leroux, F.;
Liao, S.; Licata, E.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou,
E.; Lobel, A.; Löffler, W.; López, M.; Lorenz, D.; MacDonald, I.;
Magalhães Fernandes, T.; Managau, S.; Mann, R. G.; Mantelet, G.;
Marchal, O.; Marchant, J. M.; Marconi, M.; Marinoni, S.; Marrese,
P. M.; Marschalkó, G.; Marshall, D. J.; Martín-Fleitas, J. M.;
Martino, M.; Mary, N.; Matijevič, G.; Mazeh, T.; McMillan, P. J.;
Messina, S.; Michalik, D.; Millar, N. R.; Miranda, B. M. H.; Molina,
D.; Molinaro, R.; Molinaro, M.; Molnár, L.; Moniez, M.; Montegriffo,
P.; Mor, R.; Mora, A.; Morbidelli, R.; Morel, T.; Morgenthaler, S.;
Morris, D.; Mulone, A. F.; Muraveva, T.; Musella, I.; Narbonne, J.;
Nelemans, G.; Nicastro, L.; Noval, L.; Ordénovic, C.; Ordieres-Meré,
J.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.; Palacin, H.;
Palaversa, L.; Parsons, P.; Pecoraro, M.; Pedrosa, R.; Pentikäinen,
H.; Pichon, B.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.;
Plum, G.; Poujoulet, E.; Prša, A.; Pulone, L.; Ragaini, S.; Rago,
S.; Rambaux, N.; Ramos-Lerate, M.; Ranalli, P.; Rauw, G.; Read, A.;
Regibo, S.; Reylé, C.; Ribeiro, R. A.; Rimoldini, L.; Ripepi, V.;
Riva, A.; Rixon, G.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer,
F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann, J.;
Salgado, J.; Salguero, E.; Sarasso, M.; Savietto, H.; Schultheis, M.;
Sciacca, E.; Segol, M.; Segovia, J. C.; Segransan, D.; Shih, I. -C.;
Smareglia, R.; Smart, R. L.; Solano, E.; Solitro, F.; Sordo, R.;
Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa, U.;
Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.; Stoev, H.;
Suess, F. F.; Süveges, M.; Surdej, J.; Szabados, L.; Szegedi-Elek,
E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.;
Terrett, D.; Tingley, B.; Trager, S. C.; Turon, C.; Ulla, A.; Utrilla,
E.; Valentini, G.; van Elteren, A.; Van Hemelryck, E.; vanLeeuwen,
M.; Varadi, M.; Vecchiato, A.; Veljanoski, J.; Via, T.; Vicente, D.;
Vogt, S.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler,
M.; Weingrill, K.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal,
M.; Zucker, S.; Zurbach, C.; Zwitter, T.; Alecu, A.; Allen, M.; Allende
Prieto, C.; Amorim, A.; Anglada-Escudé, G.; Arsenijevic, V.; Azaz, S.;
Balm, P.; Beck, M.; Bernstein, H. -H.; Bigot, L.; Bijaoui, A.; Blasco,
C.; Bonfigli, M.; Bono, G.; Boudreault, S.; Bressan, A.; Brown, S.;
Brunet, P. -M.; Bunclark, P.; Buonanno, R.; Butkevich, A. G.; Carret,
C.; Carrion, C.; Chemin, L.; Chéreau, F.; Corcione, L.; Darmigny,
E.; de Boer, K. S.; de Teodoro, P.; de Zeeuw, P. T.; Delle Luche,
C.; Domingues, C. D.; Dubath, P.; Fodor, F.; Frézouls, B.; Fries,
A.; Fustes, D.; Fyfe, D.; Gallardo, E.; Gallegos, J.; Gardiol, D.;
Gebran, M.; Gomboc, A.; Gómez, A.; Grux, E.; Gueguen, A.; Heyrovsky,
A.; Hoar, J.; Iannicola, G.; Isasi Parache, Y.; Janotto, A. -M.;
Joliet, E.; Jonckheere, A.; Keil, R.; Kim, D. -W.; Klagyivik, P.;
Klar, J.; Knude, J.; Kochukhov, O.; Kolka, I.; Kos, J.; Kutka, A.;
Lainey, V.; LeBouquin, D.; Liu, C.; Loreggia, D.; Makarov, V. V.;
Marseille, M. G.; Martayan, C.; Martinez-Rubi, O.; Massart, B.;
Meynadier, F.; Mignot, S.; Munari, U.; Nguyen, A. -T.; Nordlander,
T.; O'Flaherty, K. S.; Ocvirk, P.; Olias Sanz, A.; Ortiz, P.; Osorio,
J.; Oszkiewicz, D.; Ouzounis, A.; Palmer, M.; Park, P.; Pasquato, E.;
Peltzer, C.; Peralta, J.; Péturaud, F.; Pieniluoma, T.; Pigozzi, E.;
Poels, J.; Prat, G.; Prod'homme, T.; Raison, F.; Rebordao, J. M.;
Risquez, D.; Rocca-Volmerange, B.; Rosen, S.; Ruiz-Fuertes, M. I.;
Russo, F.; Sembay, S.; Serraller Vizcaino, I.; Short, A.; Siebert,
A.; Silva, H.; Sinachopoulos, D.; Slezak, E.; Soffel, M.; Sosnowska,
D.; Straižys, V.; ter Linden, M.; Terrell, D.; Theil, S.; Tiede,
C.; Troisi, L.; Tsalmantza, P.; Tur, D.; Vaccari, M.; Vachier, F.;
Valles, P.; Van Hamme, W.; Veltz, L.; Virtanen, J.; Wallut, J. -M.;
Wichmann, R.; Wilkinson, M. I.; Ziaeepour, H.; Zschocke, S.
2017A&A...601A..19G Altcode: 2017arXiv170301131G
Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric
Solution (TGAS). This is a subset of about 2 million stars for which,
besides the position and photometry, the proper motion and parallax are
calculated using HIPPARCOS and Tycho-2 positions in 1991.25 as prior
information. <BR /> Aims: We investigate the scientific potential
and limitations of the TGAS component by means of the astrometric
data for open clusters. <BR /> Methods: Mean cluster parallax and
proper motion values are derived taking into account the error
correlations within the astrometric solutions for individual stars,
an estimate of the internal velocity dispersion in the cluster, and,
where relevant, the effects of the depth of the cluster along the line
of sight. Internal consistency of the TGAS data is assessed. <BR />
Results: Values given for standard uncertainties are still inaccurate
and may lead to unrealistic unit-weight standard deviations of least
squares solutions for cluster parameters. Reconstructed mean cluster
parallax and proper motion values are generally in very good agreement
with earlier HIPPARCOS-based determination, although the Gaia mean
parallax for the Pleiades is a significant exception. We have no current
explanation for that discrepancy. Most clusters are observed to extend
to nearly 15 pc from the cluster centre, and it will be up to future
Gaia releases to establish whether those potential cluster-member stars
are still dynamically bound to the clusters. <BR /> Conclusions: The
Gaia DR1 provides the means to examine open clusters far beyond their
more easily visible cores, and can provide membership assessments
based on proper motions and parallaxes. A combined HR diagram shows
the same features as observed before using the HIPPARCOS data, with
clearly increased luminosities for older A and F dwarfs. <P />Tables
D.1 to D.19 are also available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(<A href="http://130.79.128.5">http://130.79.128.5</A>) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/601/A19">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/601/A19</A>
---------------------------------------------------------
Title: Computation of eigenfrequencies for equilibrium models
including turbulent pressure
Authors: Sonoi, T.; Belkacem, K.; Dupret, M. -A.; Samadi, R.; Ludwig,
H. -G.; Caffau, E.; Mosser, B.
2017A&A...600A..31S Altcode: 2017arXiv170107244S
Context. The space-borne missions CoRoT and Kepler have provided a
wealth of highly accurate data. However, our inability to properly
model the upper-most region of solar-like stars prevents us from
making the best of these observations. This problem is called "surface
effect" and a key ingredient to solve it is turbulent pressure for the
computation of both the equilibrium models and the oscillations. While
3D hydrodynamic simulations help to include properly the turbulent
pressure in the equilibrium models, the way this surface effect is
included in the computation of stellar oscillations is still subject
to uncertainties. <BR /> Aims: We aim at determining how to properly
include the effect of turbulent pressure and its Lagrangian perturbation
in the adiabatic computation of the oscillations. We also discuss the
validity of the gas-gamma model and reduced gamma model approximations,
which have been used to compute adiabatic oscillations of equilibrium
models including turbulent pressure. <BR /> Methods: We use a patched
model of the Sun with an inner part constructed by a 1D stellar
evolution code (CESTAM) and an outer part by the 3D hydrodynamical
code (CO<SUP>5</SUP>BOLD). Then, the adiabatic oscillations are
computed using the ADIPLS code for the gas-gamma and reduced gamma
model approximations and with the MAD code imposing the adiabatic
condition on an existing time-dependent convection formalism. Finally,
all those results are compared to the observed solar frequencies. <BR
/> Results: We show that the computation of the oscillations using the
time-dependent convection formalism in the adiabatic limit improves
significantly the agreement with the observed frequencies compared to
the gas-gamma and reduced gamma model approximations. Of the components
of the perturbation of the turbulent pressure, the perturbation of the
density and advection term is found to contribute most to the frequency
shift. <BR /> Conclusions: The turbulent pressure is certainly the
dominant factor responsible for the surface effects. Its inclusion into
the equilibrium models is thus necessary but not sufficient. Indeed,
the perturbation of the turbulent pressure must be properly taken
into account for computing adiabatic oscillation frequencies. We
propose a formalism to evaluate the frequency shift due to the
inclusion of the term with the turbulent pressure perturbation in
the variational principle in order to extrapolate our result to other
stars at various evolutionary stages. Although this work is limited to
adiabatic oscillations and the inclusion of the turbulent pressure,
future works will have to account for the nonadiabatic effect and
convective backwarming.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Gaia DR1 open cluster members
(Gaia Collaboration+, 2017)
Authors: Gaia Collaboration; van Leeuwen F.; Vallenari, A.; Jordi,
C.; Lindegren, L.; Bastian, U.; Prusti, T.; de Bruijne, J. H. J.;
Brown, A. G. A.; Babusiaux, C.; Bailer-Jones, C. A. L.; Biermann,
M.; Evans, D. W.; Eyer, L.; Jansen, F.; Klioner, S. A.; Lammers,
U.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.;
Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; Valette, V.; Walton,
N. A.; Aerts, C.; Arenou, F.; Cropper, M.; Drimmel, R.; Hog, E.; Katz,
D.; Lattanzi, M. G.; O'Mullane, W.; Grebel, E. K.; Holland, A. D.; Huc,
C.; Passot, X.; Perryman, M.; Bramante, L.; Cacciari, C.; Castaneda,
J.; Chaoul, L.; Cheek, N.; de Angeli, F.; Fabricius, C.; Guerra,
R.; Hernandez, J.; Jean-Antoine-Piccolo, A.; Masana, E.; Messineo,
R.; Mowlavi, N.; Nienartowicz, K.; Ordonez-Blanco, D.; Panuzzo, P.;
Portell, J.; Richards, P. J.; Riello, M.; Seabroke, G. M.; Tanga, P.;
Thevenin, F.; Torra, J.; Els, S. G.; Gracia-Abril, G.; Comoretto, G.;
Garcia-Reinaldos, M.; Lock, T.; Mercier, E.; Altmann, M.; Andrae,
R.; Astraatmadja, T. L.; Bellas-Velidis, I.; Benson, K.; Berthier,
J.; Blomme, R.; Busso, G.; Carry, B.; Cellino, A.; Clementini, G.;
Cowell, S.; Creevey, O.; Cuypers, J.; Davidson, M.; De Ridder, J.;
de Torres, A.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.; Fremat,
Y.; Garcia-Torres, M.; Gosset, E.; Halbwachs, J. -L.; Hambly, N. C.;
Harrison, D. L.; Hauser, M.; Hestroffer, D.; Hodgkin, S. T.; Huckle,
H. E.; Hutton, A.; Jasniewicz, G.; Jordan, S.; Kontizas, M.; Korn,
A. J.; Lanzafame, A. C.; Manteiga, M.; Moitinho, A.; Muinonen, K.;
Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J. -M.; Recio-Blanco,
A.; Robin, A. C.; Sarro, L. M.; Siopis, C.; Smith, M.; Smith, K. W.;
Sozzetti, A.; Thuillot, W.; van Reeven, W.; Viala, Y.; Abbas, U.;
Abreu Aramburu, A.; Accart, S.; Aguado, J. J.; Allan, P. M.; Allasia,
W.; Altavilla, G.; Alvarez, M. A.; Alves, J.; Anderson, R. I.; Andrei,
A. H.; Anglada Varela, E.; Antiche, E.; Antoja, T.; Anton, S.; Arcay,
B.; Bach, N.; Baker, S. G.; Balaguer-Nunez, L.; Barache, C.; Barata,
C.; Barbier, A.; Barblan, F.; Barrado, Y. Navascues D.; Barros,
M.; Barstow, M. A.; Becciani, U.; Bellazzini, M.; Bello Garcia, A.;
Belokuro, V. V.; Ben Djoya, P.; Berihuete, A.; Bianchi, L.; Bienayme,
O.; Billebaud, F.; Blagorodnova, N.; Blanco-Cuaresma, S.; Boch, T.;
Bombrun, A.; Borrachero, R.; Bouquillon, S.; Bourda, G.; Bouy, H.;
Bragaglia, A.; Breddels, M. A.; Brouillet, N.; Bruesemeister, T.;
Bucciarelli, B.; Burgess, P.; Burgon, R.; Burlacu, A.; Busonero, D.;
Buzzi, R.; Caffau, E.; Cambras, J.; Campbell, H.; Cancelliere, R.;
Cantat-Gaudin, T.; Carlucci, T.; Carrasco, J. M.; Castellani, M.;
Charlot, P.; Charnas, J.; Chiavassa, A.; Clotet, M.; Cocozza, G.;
Collins, R. S.; Costigan, G.; Crifo, F.; Cross, N. J. G.; Crosta,
M.; Crowley, C.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David,
P.; David, M.; De Cat, P.; de Felice, F.; de Laverny, P.; de Luise,
F.; de March, R.; de Martino, D.; de Souza, R.; Debosscher, J.;
Del Pozo, E.; Delbo, M.; Delgado, A.; Delgado, H. E.; Di Matteo, P.;
Diakite, S.; Distefano, E.; Dolding, C.; Dos Anjos, S.; Drazinos, P.;
Duran, J.; Dzigan, Y.; Edvardsson, B.; Enke, H.; Evans, N. W.; Eynard
Bontemps, G.; Fabre, C.; Fabrizio, M.; Faigler, S.; Falcao, A. J.;
Farras Casas, M.; Federici, L.; Fedorets, G.; Fernandez-Hernandez,
J.; Fernique, P.; Fienga, A.; Figueras, F.; Filippi, F.; Findeisen,
K.; Fonti, A.; Fouesneau, M.; Fraile, E.; Fraser, M.; Fuchs, J.;
Gai, M.; Galleti, S.; Galluccio, L.; Garabato, D.; Garcia-Sedano,
F.; Garofalo, A.; Garralda, N.; Gavras, P.; Gerssen, J.; Geyer, R.;
Gilmore, G.; Girona, S.; Giuffrida, G.; Gomes, M.; Gonzalez-Marcos,
A.; Gonzalez-Nunez, J.; Gonzalez-Vidal, J. J.; Granvik, M.; Guerrier,
A.; Guillout, P.; Guiraud, J.; Gurpide, A.; Gutierrez-Sanchez, R.;
Guy, L. P.; Haigron, R.; Hatzidimitriou, D.; Haywood, M.; Heiter,
U.; Helmi, A.; Hobbs, D.; Hofmann, W.; Holl, B.; Holland, G.; Hunt,
J. A. S.; Hypki, A.; Icardi, V.; Irwin, M.; Jevardat de Fombelle,
G.; Jofre, P.; Jonker, P. G.; Jorissen, A.; Julbe, F.; Karampelas,
A.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, E.; Koposov,
S. E.; Kordopatis, G.; Koubsky, P.; Krone-Martins, A.; Kudryashova, M.;
Kull, I.; Bachchan, R. K.; Lacoste-Seris, F.; Lanza, A. F.; Lavigne,
J. -B.; Le Poncin-Lafitte, C.; Lebreton, Y.; Lebzelter, T.; Leccia, S.;
Lecler, C. N.; Lecoeur-Taibi, I.; Lemaitre, V.; Lenhardt, H.; Leroux,
F.; Liao, S.; Licata, E.; Lindstrom, H. E. P.; Lister, T. A.; Livanou,
E.; Lobel, A.; Loeffler, W.; Lopez, M.; Lorenz, D.; MacDonald, I.;
Magalhaes Fernandes, T.; Managau, S.; Mann, R. G.; Mantelet, G.;
Marchal, O.; Marchant, J. M.; Marconi, M.; Marinoni, S.; Marrese,
P. M.; Marschalko, G.; Marshall, D. J.; Martin-Fleitas, J. M.; Martino,
M.; Mary, N.; Matijevic, G.; Mazeh, T.; McMillan, P. J.; Messina, S.;
Michalik, D.; Millar, N. R.; Miranda, B. M. H.; Molina, D.; Molinaro,
R.; Molinaro, M.; Molnar, L.; Moniez, M.; Montegriffo, P.; Mor, R.;
Mora, A.; Morbidelli, R.; Morel, T.; Morgenthaler, S.; Morris, D.;
Mulone, A. F.; Muraveva, T.; Musella, I.; Narbonne, J.; Nelemans, G.;
Nicastro, L.; Noval, L.; Ordenovic, C.; Ordieres-Mere, J.; Osborne,
P.; Pagani, C.; Pagano, I.; Pailler, F.; Palacin, H.; Palaversa, L.;
Parsons, P.; Pecoraro, M.; Pedrosa, R.; Pentikaeinen, H.; Pichon, B.;
Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poujoulet, E.;
Prsa, A.; Pulone, L.; Ragaini, S.; Rago, S.; Rambaux, N.; Ramos-Lerate,
M.; Ranalli, P.; Rauw, G.; Read, A.; Regibo, S.; Reyle, C.; Ribeiro,
R. A.; Rimoldini, L.; Ripepi, V.; Riva, A.; Rixon, G.; Roelens, M.;
Romero-Gomez, M.; Rowell, N.; Royer, F.; Ruiz-Dern, L.; Sadowski,
G.; Sagrista Selles, T.; Sahlmann, J.; Salgado, J.; Salguero, E.;
Sarasso, M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol, M.;
Segovia, J. C.; Segransan, D.; Shih, I. -C.; Smareglia, R.; Smart,
R. L.; Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay,
J.; Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmueller,
H.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Sueveges, M.; Surdej,
J.; Szabados, L.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran,
G.; Taylor, M. B.; Teixeira, R.; Terrett, D.; Tingley, B.; Trager,
S. C.; Turon, C.; Ulla, A.; Utrilla, E.; Valentini, G.; van Elteren,
A.; van Hemelryck, E.; Vanleeuwen, M.; Varadi, M.; Vecchiato, A.;
Veljanoski, J.; Via, T.; Vicente, D.; Vogt, S.; Voss, H.; Votruba,
V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Weingrill, K.; Wevers,
T.; Wyrzykowski, L.; Yoldas, A.; Zerjal, M.; Zucker, S.; Zurbach,
C.; Zwitter, T.; Alecu, A.; Allen, M.; Allende Prieto, C.; Amorim,
A.; Anglada-Escude, G.; Arsenijevic, V.; Azaz, S.; Balm, P.; Beck,
M.; Bernstein, H. -H.; Bigot, L.; Bijaoui, A.; Blasco, C.; Bonfigli,
M.; Bono, G.; Boudreault, S.; Bressan, A.; Brown, S.; Brunet, P. -M.;
Bunclark, P.; Buonanno, R.; Butkevich, A. G.; Carret, C.; Carrion, C.;
Chemin, L.; Chereau, F.; Corcione, L.; Darmigny, E.; de Boer, K. S.;
de Teodoro, P.; de Zeeuw, P. T.; Delle Luche, C.; Domingues, C. D.;
Dubath, P.; Fodor, F.; Frezouls, B.; Fries, A.; Fustes, D.; Fyfe,
D.; Gallardo, E.; Gallegos, J.; Gardiol, D.; Gebran, M.; Gomboc, A.;
Gomez, A.; Grux, E.; Gueguen, A.; Heyrovsky, A.; Hoar, J.; Iannicola,
G.; Isasi Parache, Y.; Janotto, A. -M.; Joliet, E.; Jonckheere, A.;
Keil, R.; Kim, D. -W.; Klagyivik, P.; Klar, J.; Knude, J.; Kochukhov,
O.; Kolka, I.; Kos, J.; Kutka, A.; Lainey, V.; Lebouquin, D.; Liu,
C.; Loreggia, D.; Makarov, V. V.; Marseille, M. G.; Martayan, C.;
Martinez-Rubi, O.; Massart, B.; Meynadier, F.; Mignot, S.; Munari,
U.; Nguyen, A. -T.; Nordlander, T.; O'Flaherty, K. S.; Ocvirk, P.;
Olias Sanz, A.; Ortiz, P.; Osorio, J.; Oszkiewicz, D.; Ouzounis, A.;
Palmer, M.; Park, P.; Pasquato, E.; Peltzer, C.; Peralta, J.; Peturaud,
F.; Pieniluoma, T.; Pigozzi, E.; Poels, J.; Prat, G.; Prod'homme, T.;
Raison, F.; Rebordao, J. M.; Risquez, D.; Rocca-Volmerange, B.; Rosen,
S.; Ruiz-Fuertes, M. I.; Russo, F.; Sembay, S.; Serraller Vizcaino,
I.; Short, A.; Siebert, A.; Silva, H.; Sinachopoulos, D.; Slezak, E.;
Soffel, M.; Sosnowska, D.; Straizys, V.; Ter Linden, M.; Terrell, D.;
Theil, S.; Tiede, C.; Troisi, L.; Tsalmantza, P.; Tur, D.; Vaccari,
M.; Vachier, F.; Valles, P.; van Hamme, W.; Veltz, L.; Virtanen,
J.; Wallut, J. -M.; Wichmann, R.; Wilkinson, M. I.; Ziaeepour, H.;
Zschocke, S.
2017yCat..36010019G Altcode:
We have determined and examined the astrometric data for 19 open
clusters, ranging from the Hyades at just under 47pc to NGC 2422
at nearly 440pc. The clusters are : the Hyades, Coma Berenices, the
Pleiades, Praesepe, alpha Per, IC 2391, IC 2602, Blanco 1, NGC 2451,
NGC 6475, NGC 7092, NGC 2516, NGC 2232, IC 4665, NGC 6633, Collinder
140, NGC 2422, NGC 3532 and NGC 2547. <P />(2 data files).
---------------------------------------------------------
Title: VizieR Online Data Catalog: NGC104 RGB Na, Mg, and K abundances
(Cerniauskas+, 2017)
Authors: Cerniauskas, A.; Kucinskas, A.; Klevas, J.; Prakapavicius,
D.; Korotin, S.; Bonifacio, P.; Ludwig, H. -G.; Caffau, E.; Steffen, M.
2017yCat..36040035C Altcode:
We used 2dF/HERMES spectra obtained in two wavelength regions,
564.9-587.3nm (GREEN) and 758.5-788.7nm (IR), using the spectral
resolution of R~28000 and exposure time of 1200s. The observations
were carried out during the period of Oct 22 - Dec 20, 2013 <P />(1
data file).
---------------------------------------------------------
Title: An in-depth spectroscopic examination of molecular bands from
3D hydrodynamical model atmospheres. II. Carbon-enhanced metal-poor
3D model atmospheres
Authors: Gallagher, A. J.; Caffau, E.; Bonifacio, P.; Ludwig, H. -G.;
Steffen, M.; Homeier, D.; Plez, B.
2017A&A...598L..10G Altcode: 2017arXiv170109102G
Context. Tighter constraints on metal-poor stars we observe are
needed to better understand the chemical processes of the early
Universe. Computing a stellar spectrum in 3D allows one to model complex
stellar behaviours, which cannot be replicated in 1D. <BR /> Aims:
We examine the effect that the intrinsic CNO abundances have on a 3D
model structure and the resulting 3D spectrum synthesis. <BR /> Methods:
Model atmospheres were computed in 3D for three distinct CNO chemical
compositions using the CO<SUP>5</SUP>BOLD model atmosphere code,
and their internal structures were examined. Synthetic spectra were
computed from these models using Linfor3D and they were compared. New
3D abundance corrections for the G-band and a selection of UV OH lines
were also computed. <BR /> Results: The varying CNO abundances change
the metal content of the 3D models. This had an effect on the model
structure and the resulting synthesis. However, it was found that
the C/O ratio had a larger effect than the overall metal content of
a model. <BR /> Conclusions: Our results suggest that varying the
C/O ratio has a substantial impact on the internal structure of the
3D model, even in the hot turn-off star models explored here. This
suggests that bespoke 3D models, for specific CNO abundances should
be sought. Such effects are not seen in 1D at these temperature regimes.
---------------------------------------------------------
Title: 3D non-LTE corrections for the <SUP>6</SUP>Li/<SUP>7</SUP>Li
isotopic ratio in solar-type stars
Authors: Harutyunyan, G.; Steffen, M.; Mott, A.; Caffau, E.; Israelian,
G.; González Hernández, J. I.; Strassmeier, K. G.
2017MmSAI..88...61H Altcode:
Doppler shifts induced by convective motions in stellar atmospheres
affect the shape of spectral absorption lines and create slightly
asymmetric line profiles. It is important to take this effect into
account in modeling the subtle depression created by the <SUP>6</SUP>Li
isotope which lies on the red wing of the Li I 670.8 nm resonance
doublet line, since convective motions in stellar atmospheres can mimic
a presence of <SUP>6</SUP>Li when intrinsically symmetric theoretical
line profiles are presumed for the analysis of the <SUP>7</SUP>Li
doublet \citep{cayrel2007}. Based on CO5BOLD hydrodynamical model
atmospheres, we compute 3D non-local thermodynamic equilibrium
(NLTE) corrections for the <SUP>6</SUP>Li/<SUP>7</SUP>Li isotopic
ratio by using a grid of 3D NLTE and 1D LTE synthetic spectra. These
corrections must be added to the results of the 1D LTE analysis to
correct them for the combined 3D non-LTE effects. As one would expect,
the resulting corrections are always negative and they range between
0 and -5 %, depending on effective temperature, surface gravity, and
metallicity. For each metallicity we derive an analytic expression
approximating the 3D NLTE corrections as a function of effective
temperature, surface gravity and projected rotational velocity.
---------------------------------------------------------
Title: Using CO5BOLD models to predict the effects of granulation
on colours .
Authors: Bonifacio, P.; Caffau, E.; Ludwig, H. -G.; Steffen, M.;
Castelli, F.; Gallagher, A. J.; Prakapavičius, D.; Kučinskas, A.;
Cayrel, R.; Freytag, B.; Plez, B.; Homeier, D.
2017MmSAI..88...90B Altcode:
In order to investigate the effects of granulation on fluxes and
colours, we computed the emerging fluxes from the models in the
CO5BOLD grid with metallicities [M/H]=0.0,-1.0,-2.0 and -3.0. These
fluxes have been used to compute colours in different photometric
systems. We explain here how our computations have been performed and
provide some results.
---------------------------------------------------------
Title: Enhanced methods for computing spectra from CO5BOLD models
using Linfor3D. Molecular bands in metal-poor stars
Authors: Gallagher, A. J.; Steffen, M.; Caffau, E.; Bonifacio, P.;
Ludwig, H. -G.; Freytag, B.
2017MmSAI..88...82G Altcode: 2016arXiv161004427G
Molecular features such as the G-band, CN-band and NH-band are important
diagnostics for measuring a star's carbon and nitrogen abundances,
especially in metal-poor stars where atomic lines are no longer visible
in stellar spectra. Unlike atomic transitions, molecular features
tend to form in bands, which cover large wavelength regions in a
spectrum. While it is a trivial matter to compute carbon and nitrogen
molecular bands under the assumption of 1D, it is extremely time
consuming in 3D. In this contribution to the 2016 COBOLD workshop we
review the improvements made to the 3D spectral synthesis code Linfor3D,
and discuss the new challenges found when computing molecular features
in 3D.
---------------------------------------------------------
Title: Lithium in the active sub-giant HD123351. A quantitative
analysis with 3D and 1D model atmospheres using different observed
spectra
Authors: Mott, A.; Steffen, M.; Caffau, E.; Strassmeier, K. G.
2017MmSAI..88...68M Altcode:
Current 3D hydrodynamical model atmosphere simulations together with
non-LTE spectrum synthesis calculations permit to determine reliable
atomic and in particular isotopic chemical abundances. Although this
approach is computationally time demanding, it became feasible in
studying lithium in stellar spectra. In the literature not much is
known about the presence of the more fragile {<SUP>6</SUP>Li} isotope
in evolved metal-rich objects. In this case the analysis is complicated
by the lack of a suitable list of atomic and molecular lines in the
spectral region of the lithium resonance line at 670.8 nm. <P />Here we
present a spectroscopic comparative analysis of the Li doublet region
of HD 123351, an active sub-giant star of solar metallicity. We fit
the Li profile in three observed spectra characterized by different
qualities: two very-high resolution spectra (Gecko@CFHT, R=120 000,
SNR=400 and PEPSI@LBT, R=150 000, SNR=663) and a high-resolution
SOPHIE@OHP spectrum (R=40 000, SNR=300). We adopt a set of model
atmospheres, both 3D and 1D, having different stellar parameters
(T_{eff} and log g). The 3D models are taken from the CIFIST grid of
COBOLD model atmospheres and departures from LTE are considered for
the lithium components. For the blends other than the lithium in this
wavelength region we adopt the linelist of \citet{melendez12}. We find
consistent results for all three observations and an overall good fit
with the selected list of atomic and molecular lines, indicating a
high {<SUP>6</SUP>Li} content. <P />The presence of {<SUP>6</SUP>Li}
is not expected in cool stellar atmospheres. Its detection is of
crucial importance for understanding mixing processes in stars and
external lithium production mechanisms, possibly related to stellar
activity or planetray accretion of {<SUP>6</SUP>Li}-rich material.
---------------------------------------------------------
Title: Investigation of the solar centre-to-limb variation of oxygen
and lithium spectral features
Authors: Caffau, E.; Malherbe, J. -M.; Steffen, M.; Ludwig, H. -G.;
Mott, A.
2017MmSAI..88...45C Altcode:
We compare intensity spectra of the Sun observed at different limb
angles in the wavelength range covering the forbidden oxygen lines and
the lithium resonance feature with line formation computations performed
on a CO5BOLD 3D hydrodynamical simulation of the solar atmosphere. Among
the prime oxygen abundance indicators, the forbidden line at 630 nm
is contaminated with a significant Ni I blend. The availability of
observations at different positions on the solar disc allows us to
disentangle the contributions of oxygen and nickel and to derive their
individual abundances. We derived in the past, from the [OI] line,
A(O)=8.73± 0.05 with a nickel abundance of A(Ni)=6.1± 0.04. From
the observations here presented, we obtain A(O)=8.71 and A(Ni)=6.09,
in excellent agreement with the previous result. For lithium, we
investigated the Li doublet at 670.7 nm and compared synthetic spectra
of the Li spectra range based on different line-lists available in the
literature to the observed data. With these observations, we are still
unable to conclude on which is the best line-list to be used for the
blending lines.
---------------------------------------------------------
Title: The Gaia mission
Authors: Gaia Collaboration; Prusti, T.; de Bruijne, J. H. J.; Brown,
A. G. A.; Vallenari, A.; Babusiaux, C.; Bailer-Jones, C. A. L.;
Bastian, U.; Biermann, M.; Evans, D. W.; Eyer, L.; Jansen, F.; Jordi,
C.; Klioner, S. A.; Lammers, U.; Lindegren, L.; Luri, X.; Mignard, F.;
Milligan, D. J.; Panem, C.; Poinsignon, V.; Pourbaix, D.; Randich, S.;
Sarri, G.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; Valette,
V.; van Leeuwen, F.; Walton, N. A.; Aerts, C.; Arenou, F.; Cropper,
M.; Drimmel, R.; Høg, E.; Katz, D.; Lattanzi, M. G.; O'Mullane, W.;
Grebel, E. K.; Holland, A. D.; Huc, C.; Passot, X.; Bramante, L.;
Cacciari, C.; Castañeda, J.; Chaoul, L.; Cheek, N.; De Angeli, F.;
Fabricius, C.; Guerra, R.; Hernández, J.; Jean-Antoine-Piccolo,
A.; Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.;
Ordóñez-Blanco, D.; Panuzzo, P.; Portell, J.; Richards, P. J.;
Riello, M.; Seabroke, G. M.; Tanga, P.; Thévenin, F.; Torra, J.;
Els, S. G.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.;
Lock, T.; Mercier, E.; Altmann, M.; Andrae, R.; Astraatmadja, T. L.;
Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme, R.; Busso,
G.; Carry, B.; Cellino, A.; Clementini, G.; Cowell, S.; Creevey, O.;
Cuypers, J.; Davidson, M.; De Ridder, J.; de Torres, A.; Delchambre,
L.; Dell'Oro, A.; Ducourant, C.; Frémat, Y.; García-Torres, M.;
Gosset, E.; Halbwachs, J. -L.; Hambly, N. C.; Harrison, D. L.;
Hauser, M.; Hestroffer, D.; Hodgkin, S. T.; Huckle, H. E.; Hutton,
A.; Jasniewicz, G.; Jordan, S.; Kontizas, M.; Korn, A. J.; Lanzafame,
A. C.; Manteiga, M.; Moitinho, A.; Muinonen, K.; Osinde, J.; Pancino,
E.; Pauwels, T.; Petit, J. -M.; Recio-Blanco, A.; Robin, A. C.; Sarro,
L. M.; Siopis, C.; Smith, M.; Smith, K. W.; Sozzetti, A.; Thuillot,
W.; van Reeven, W.; Viala, Y.; Abbas, U.; Abreu Aramburu, A.; Accart,
S.; Aguado, J. J.; Allan, P. M.; Allasia, W.; Altavilla, G.; Álvarez,
M. A.; Alves, J.; Anderson, R. I.; Andrei, A. H.; Anglada Varela, E.;
Antiche, E.; Antoja, T.; Antón, S.; Arcay, B.; Atzei, A.; Ayache, L.;
Bach, N.; Baker, S. G.; Balaguer-Núñez, L.; Barache, C.; Barata,
C.; Barbier, A.; Barblan, F.; Baroni, M.; Barrado y Navascués, D.;
Barros, M.; Barstow, M. A.; Becciani, U.; Bellazzini, M.; Bellei, G.;
Bello García, A.; Belokurov, V.; Bendjoya, P.; Berihuete, A.; Bianchi,
L.; Bienaymé, O.; Billebaud, F.; Blagorodnova, N.; Blanco-Cuaresma,
S.; Boch, T.; Bombrun, A.; Borrachero, R.; Bouquillon, S.; Bourda, G.;
Bouy, H.; Bragaglia, A.; Breddels, M. A.; Brouillet, N.; Brüsemeister,
T.; Bucciarelli, B.; Budnik, F.; Burgess, P.; Burgon, R.; Burlacu,
A.; Busonero, D.; Buzzi, R.; Caffau, E.; Cambras, J.; Campbell, H.;
Cancelliere, R.; Cantat-Gaudin, T.; Carlucci, T.; Carrasco, J. M.;
Castellani, M.; Charlot, P.; Charnas, J.; Charvet, P.; Chassat, F.;
Chiavassa, A.; Clotet, M.; Cocozza, G.; Collins, R. S.; Collins, P.;
Costigan, G.; Crifo, F.; Cross, N. J. G.; Crosta, M.; Crowley, C.;
Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; De
Cat, P.; de Felice, F.; de Laverny, P.; De Luise, F.; De March, R.;
de Martino, D.; de Souza, R.; Debosscher, J.; del Pozo, E.; Delbo, M.;
Delgado, A.; Delgado, H. E.; di Marco, F.; Di Matteo, P.; Diakite, S.;
Distefano, E.; Dolding, C.; Dos Anjos, S.; Drazinos, P.; Durán, J.;
Dzigan, Y.; Ecale, E.; Edvardsson, B.; Enke, H.; Erdmann, M.; Escolar,
D.; Espina, M.; Evans, N. W.; Eynard Bontemps, G.; Fabre, C.; Fabrizio,
M.; Faigler, S.; Falcão, A. J.; Farràs Casas, M.; Faye, F.; Federici,
L.; Fedorets, G.; Fernández-Hernández, J.; Fernique, P.; Fienga, A.;
Figueras, F.; Filippi, F.; Findeisen, K.; Fonti, A.; Fouesneau, M.;
Fraile, E.; Fraser, M.; Fuchs, J.; Furnell, R.; Gai, M.; Galleti, S.;
Galluccio, L.; Garabato, D.; García-Sedano, F.; Garé, P.; Garofalo,
A.; Garralda, N.; Gavras, P.; Gerssen, J.; Geyer, R.; Gilmore,
G.; Girona, S.; Giuffrida, G.; Gomes, M.; González-Marcos, A.;
González-Núñez, J.; González-Vidal, J. J.; Granvik, M.; Guerrier,
A.; Guillout, P.; Guiraud, J.; Gúrpide, A.; Gutiérrez-Sánchez,
R.; Guy, L. P.; Haigron, R.; Hatzidimitriou, D.; Haywood, M.; Heiter,
U.; Helmi, A.; Hobbs, D.; Hofmann, W.; Holl, B.; Holland, G.; Hunt,
J. A. S.; Hypki, A.; Icardi, V.; Irwin, M.; Jevardat de Fombelle,
G.; Jofré, P.; Jonker, P. G.; Jorissen, A.; Julbe, F.; Karampelas,
A.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, E.; Koposov,
S. E.; Kordopatis, G.; Koubsky, P.; Kowalczyk, A.; Krone-Martins, A.;
Kudryashova, M.; Kull, I.; Bachchan, R. K.; Lacoste-Seris, F.; Lanza,
A. F.; Lavigne, J. -B.; Le Poncin-Lafitte, C.; Lebreton, Y.; Lebzelter,
T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Lemaitre, V.; Lenhardt,
H.; Leroux, F.; Liao, S.; Licata, E.; Lindstrøm, H. E. P.; Lister,
T. A.; Livanou, E.; Lobel, A.; Löffler, W.; López, M.; Lopez-Lozano,
A.; Lorenz, D.; Loureiro, T.; MacDonald, I.; Magalhães Fernandes, T.;
Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant, J. M.;
Marconi, M.; Marie, J.; Marinoni, S.; Marrese, P. M.; Marschalkó,
G.; Marshall, D. J.; Martín-Fleitas, J. M.; Martino, M.; Mary, N.;
Matijevič, G.; Mazeh, T.; McMillan, P. J.; Messina, S.; Mestre, A.;
Michalik, D.; Millar, N. R.; Miranda, B. M. H.; Molina, D.; Molinaro,
R.; Molinaro, M.; Molnár, L.; Moniez, M.; Montegriffo, P.; Monteiro,
D.; Mor, R.; Mora, A.; Morbidelli, R.; Morel, T.; Morgenthaler, S.;
Morley, T.; Morris, D.; Mulone, A. F.; Muraveva, T.; Musella, I.;
Narbonne, J.; Nelemans, G.; Nicastro, L.; Noval, L.; Ordénovic, C.;
Ordieres-Meré, J.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.;
Palacin, H.; Palaversa, L.; Parsons, P.; Paulsen, T.; Pecoraro, M.;
Pedrosa, R.; Pentikäinen, H.; Pereira, J.; Pichon, B.; Piersimoni,
A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poujoulet, E.; Prša,
A.; Pulone, L.; Ragaini, S.; Rago, S.; Rambaux, N.; Ramos-Lerate,
M.; Ranalli, P.; Rauw, G.; Read, A.; Regibo, S.; Renk, F.; Reylé,
C.; Ribeiro, R. A.; Rimoldini, L.; Ripepi, V.; Riva, A.; Rixon, G.;
Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer, F.; Rudolph, A.;
Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann, J.;
Salgado, J.; Salguero, E.; Sarasso, M.; Savietto, H.; Schnorhk, A.;
Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Segransan,
D.; Serpell, E.; Shih, I. -C.; Smareglia, R.; Smart, R. L.; Smith,
C.; Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.;
Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmüller, H.;
Stephenson, C. A.; Stoev, H.; Suess, F. F.; Süveges, M.; Surdej, J.;
Szabados, L.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran, G.;
Taylor, M. B.; Teixeira, R.; Terrett, D.; Tingley, B.; Trager, S. C.;
Turon, C.; Ulla, A.; Utrilla, E.; Valentini, G.; van Elteren, A.; Van
Hemelryck, E.; van Leeuwen, M.; Varadi, M.; Vecchiato, A.; Veljanoski,
J.; Via, T.; Vicente, D.; Vogt, S.; Voss, H.; Votruba, V.; Voutsinas,
S.; Walmsley, G.; Weiler, M.; Weingrill, K.; Werner, D.; Wevers, T.;
Whitehead, G.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Zucker, S.;
Zurbach, C.; Zwitter, T.; Alecu, A.; Allen, M.; Allende Prieto, C.;
Amorim, A.; Anglada-Escudé, G.; Arsenijevic, V.; Azaz, S.; Balm,
P.; Beck, M.; Bernstein, H. -H.; Bigot, L.; Bijaoui, A.; Blasco,
C.; Bonfigli, M.; Bono, G.; Boudreault, S.; Bressan, A.; Brown, S.;
Brunet, P. -M.; Bunclark, P.; Buonanno, R.; Butkevich, A. G.; Carret,
C.; Carrion, C.; Chemin, L.; Chéreau, F.; Corcione, L.; Darmigny,
E.; de Boer, K. S.; de Teodoro, P.; de Zeeuw, P. T.; Delle Luche,
C.; Domingues, C. D.; Dubath, P.; Fodor, F.; Frézouls, B.; Fries,
A.; Fustes, D.; Fyfe, D.; Gallardo, E.; Gallegos, J.; Gardiol, D.;
Gebran, M.; Gomboc, A.; Gómez, A.; Grux, E.; Gueguen, A.; Heyrovsky,
A.; Hoar, J.; Iannicola, G.; Isasi Parache, Y.; Janotto, A. -M.;
Joliet, E.; Jonckheere, A.; Keil, R.; Kim, D. -W.; Klagyivik, P.;
Klar, J.; Knude, J.; Kochukhov, O.; Kolka, I.; Kos, J.; Kutka, A.;
Lainey, V.; LeBouquin, D.; Liu, C.; Loreggia, D.; Makarov, V. V.;
Marseille, M. G.; Martayan, C.; Martinez-Rubi, O.; Massart, B.;
Meynadier, F.; Mignot, S.; Munari, U.; Nguyen, A. -T.; Nordlander,
T.; Ocvirk, P.; O'Flaherty, K. S.; Olias Sanz, A.; Ortiz, P.; Osorio,
J.; Oszkiewicz, D.; Ouzounis, A.; Palmer, M.; Park, P.; Pasquato, E.;
Peltzer, C.; Peralta, J.; Péturaud, F.; Pieniluoma, T.; Pigozzi, E.;
Poels, J.; Prat, G.; Prod'homme, T.; Raison, F.; Rebordao, J. M.;
Risquez, D.; Rocca-Volmerange, B.; Rosen, S.; Ruiz-Fuertes, M. I.;
Russo, F.; Sembay, S.; Serraller Vizcaino, I.; Short, A.; Siebert,
A.; Silva, H.; Sinachopoulos, D.; Slezak, E.; Soffel, M.; Sosnowska,
D.; Straižys, V.; ter Linden, M.; Terrell, D.; Theil, S.; Tiede,
C.; Troisi, L.; Tsalmantza, P.; Tur, D.; Vaccari, M.; Vachier, F.;
Valles, P.; Van Hamme, W.; Veltz, L.; Virtanen, J.; Wallut, J. -M.;
Wichmann, R.; Wilkinson, M. I.; Ziaeepour, H.; Zschocke, S.
2016A&A...595A...1G Altcode: 2016arXiv160904153G
Gaia is a cornerstone mission in the science programme of the
EuropeanSpace Agency (ESA). The spacecraft construction was approved
in 2006, following a study in which the original interferometric
concept was changed to a direct-imaging approach. Both the spacecraft
and the payload were built by European industry. The involvement
of the scientific community focusses on data processing for which
the international Gaia Data Processing and Analysis Consortium
(DPAC) was selected in 2007. Gaia was launched on 19 December 2013
and arrived at its operating point, the second Lagrange point of
the Sun-Earth-Moon system, a few weeks later. The commissioning
of the spacecraft and payload was completed on 19 July 2014. The
nominal five-year mission started with four weeks of special,
ecliptic-pole scanning and subsequently transferred into full-sky
scanning mode. We recall the scientific goals of Gaia and give a
description of the as-built spacecraft that is currently (mid-2016)
being operated to achieve these goals. We pay special attention to
the payload module, the performance of which is closely related to
the scientific performance of the mission. We provide a summary of
the commissioning activities and findings, followed by a description
of the routine operational mode. We summarise scientific performance
estimates on the basis of in-orbit operations. Several intermediate
Gaia data releases are planned and the data can be retrieved from the
Gaia Archive, which is available through the Gaia home page. <P /><A
href="http://www.cosmos.esa.int/gaia">http://www.cosmos.esa.int/gaia</A>
---------------------------------------------------------
Title: Gaia Data Release 1. Summary of the astrometric, photometric,
and survey properties
Authors: Gaia Collaboration; Brown, A. G. A.; Vallenari, A.; Prusti,
T.; de Bruijne, J. H. J.; Mignard, F.; Drimmel, R.; Babusiaux, C.;
Bailer-Jones, C. A. L.; Bastian, U.; Biermann, M.; Evans, D. W.;
Eyer, L.; Jansen, F.; Jordi, C.; Katz, D.; Klioner, S. A.; Lammers,
U.; Lindegren, L.; Luri, X.; O'Mullane, W.; Panem, C.; Pourbaix, D.;
Randich, S.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; Valette,
V.; van Leeuwen, F.; Walton, N. A.; Aerts, C.; Arenou, F.; Cropper,
M.; Høg, E.; Lattanzi, M. G.; Grebel, E. K.; Holland, A. D.; Huc,
C.; Passot, X.; Perryman, M.; Bramante, L.; Cacciari, C.; Castañeda,
J.; Chaoul, L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.;
Hernández, J.; Jean-Antoine-Piccolo, A.; Masana, E.; Messineo, R.;
Mowlavi, N.; Nienartowicz, K.; Ordóñez-Blanco, D.; Panuzzo, P.;
Portell, J.; Richards, P. J.; Riello, M.; Seabroke, G. M.; Tanga, P.;
Thévenin, F.; Torra, J.; Els, S. G.; Gracia-Abril, G.; Comoretto,
G.; Garcia-Reinaldos, M.; Lock, T.; Mercier, E.; Altmann, M.; Andrae,
R.; Astraatmadja, T. L.; Bellas-Velidis, I.; Benson, K.; Berthier,
J.; Blomme, R.; Busso, G.; Carry, B.; Cellino, A.; Clementini, G.;
Cowell, S.; Creevey, O.; Cuypers, J.; Davidson, M.; De Ridder, J.;
de Torres, A.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.; Frémat,
Y.; García-Torres, M.; Gosset, E.; Halbwachs, J. -L.; Hambly, N. C.;
Harrison, D. L.; Hauser, M.; Hestroffer, D.; Hodgkin, S. T.; Huckle,
H. E.; Hutton, A.; Jasniewicz, G.; Jordan, S.; Kontizas, M.; Korn,
A. J.; Lanzafame, A. C.; Manteiga, M.; Moitinho, A.; Muinonen, K.;
Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J. -M.; Recio-Blanco,
A.; Robin, A. C.; Sarro, L. M.; Siopis, C.; Smith, M.; Smith, K. W.;
Sozzetti, A.; Thuillot, W.; van Reeven, W.; Viala, Y.; Abbas, U.;
Abreu Aramburu, A.; Accart, S.; Aguado, J. J.; Allan, P. M.; Allasia,
W.; Altavilla, G.; Álvarez, M. A.; Alves, J.; Anderson, R. I.; Andrei,
A. H.; Anglada Varela, E.; Antiche, E.; Antoja, T.; Antón, S.; Arcay,
B.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.; Barache, C.; Barata,
C.; Barbier, A.; Barblan, F.; Barrado y Navascués, D.; Barros, M.;
Barstow, M. A.; Becciani, U.; Bellazzini, M.; Bello García, A.;
Belokurov, V.; Bendjoya, P.; Berihuete, A.; Bianchi, L.; Bienaymé,
O.; Billebaud, F.; Blagorodnova, N.; Blanco-Cuaresma, S.; Boch, T.;
Bombrun, A.; Borrachero, R.; Bouquillon, S.; Bourda, G.; Bouy, H.;
Bragaglia, A.; Breddels, M. A.; Brouillet, N.; Brüsemeister, T.;
Bucciarelli, B.; Burgess, P.; Burgon, R.; Burlacu, A.; Busonero, D.;
Buzzi, R.; Caffau, E.; Cambras, J.; Campbell, H.; Cancelliere, R.;
Cantat-Gaudin, T.; Carlucci, T.; Carrasco, J. M.; Castellani, M.;
Charlot, P.; Charnas, J.; Chiavassa, A.; Clotet, M.; Cocozza, G.;
Collins, R. S.; Costigan, G.; Crifo, F.; Cross, N. J. G.; Crosta, M.;
Crowley, C.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.;
David, M.; De Cat, P.; de Felice, F.; de Laverny, P.; De Luise, F.;
De March, R.; de Martino, D.; de Souza, R.; Debosscher, J.; del Pozo,
E.; Delbo, M.; Delgado, A.; Delgado, H. E.; Di Matteo, P.; Diakite, S.;
Distefano, E.; Dolding, C.; Dos Anjos, S.; Drazinos, P.; Duran, J.;
Dzigan, Y.; Edvardsson, B.; Enke, H.; Evans, N. W.; Eynard Bontemps,
G.; Fabre, C.; Fabrizio, M.; Faigler, S.; Falcão, A. J.; Farràs
Casas, M.; Federici, L.; Fedorets, G.; Fernández-Hernández, J.;
Fernique, P.; Fienga, A.; Figueras, F.; Filippi, F.; Findeisen, K.;
Fonti, A.; Fouesneau, M.; Fraile, E.; Fraser, M.; Fuchs, J.; Gai, M.;
Galleti, S.; Galluccio, L.; Garabato, D.; García-Sedano, F.; Garofalo,
A.; Garralda, N.; Gavras, P.; Gerssen, J.; Geyer, R.; Gilmore,
G.; Girona, S.; Giuffrida, G.; Gomes, M.; González-Marcos, A.;
González-Núñez, J.; González-Vidal, J. J.; Granvik, M.; Guerrier,
A.; Guillout, P.; Guiraud, J.; Gúrpide, A.; Gutiérrez-Sánchez,
R.; Guy, L. P.; Haigron, R.; Hatzidimitriou, D.; Haywood, M.; Heiter,
U.; Helmi, A.; Hobbs, D.; Hofmann, W.; Holl, B.; Holland, G.; Hunt,
J. A. S.; Hypki, A.; Icardi, V.; Irwin, M.; Jevardat de Fombelle,
G.; Jofré, P.; Jonker, P. G.; Jorissen, A.; Julbe, F.; Karampelas,
A.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, E.; Koposov,
S. E.; Kordopatis, G.; Koubsky, P.; Krone-Martins, A.; Kudryashova, M.;
Kull, I.; Bachchan, R. K.; Lacoste-Seris, F.; Lanza, A. F.; Lavigne,
J. -B.; Le Poncin-Lafitte, C.; Lebreton, Y.; Lebzelter, T.; Leccia, S.;
Leclerc, N.; Lecoeur-Taibi, I.; Lemaitre, V.; Lenhardt, H.; Leroux, F.;
Liao, S.; Licata, E.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou,
E.; Lobel, A.; Löffler, W.; López, M.; Lorenz, D.; MacDonald, I.;
Magalhães Fernandes, T.; Managau, S.; Mann, R. G.; Mantelet, G.;
Marchal, O.; Marchant, J. M.; Marconi, M.; Marinoni, S.; Marrese,
P. M.; Marschalkó, G.; Marshall, D. J.; Martín-Fleitas, J. M.;
Martino, M.; Mary, N.; Matijevič, G.; Mazeh, T.; McMillan, P. J.;
Messina, S.; Michalik, D.; Millar, N. R.; Miranda, B. M. H.; Molina,
D.; Molinaro, R.; Molinaro, M.; Molnár, L.; Moniez, M.; Montegriffo,
P.; Mor, R.; Mora, A.; Morbidelli, R.; Morel, T.; Morgenthaler, S.;
Morris, D.; Mulone, A. F.; Muraveva, T.; Musella, I.; Narbonne, J.;
Nelemans, G.; Nicastro, L.; Noval, L.; Ordénovic, C.; Ordieres-Meré,
J.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.; Palacin, H.;
Palaversa, L.; Parsons, P.; Pecoraro, M.; Pedrosa, R.; Pentikäinen,
H.; Pichon, B.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.;
Plum, G.; Poujoulet, E.; Prša, A.; Pulone, L.; Ragaini, S.; Rago,
S.; Rambaux, N.; Ramos-Lerate, M.; Ranalli, P.; Rauw, G.; Read, A.;
Regibo, S.; Reylé, C.; Ribeiro, R. A.; Rimoldini, L.; Ripepi, V.;
Riva, A.; Rixon, G.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer,
F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann, J.;
Salgado, J.; Salguero, E.; Sarasso, M.; Savietto, H.; Schultheis, M.;
Sciacca, E.; Segol, M.; Segovia, J. C.; Segransan, D.; Shih, I. -C.;
Smareglia, R.; Smart, R. L.; Solano, E.; Solitro, F.; Sordo, R.;
Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa, U.;
Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.; Stoev, H.;
Suess, F. F.; Süveges, M.; Surdej, J.; Szabados, L.; Szegedi-Elek,
E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.;
Terrett, D.; Tingley, B.; Trager, S. C.; Turon, C.; Ulla, A.; Utrilla,
E.; Valentini, G.; van Elteren, A.; Van Hemelryck, E.; van Leeuwen,
M.; Varadi, M.; Vecchiato, A.; Veljanoski, J.; Via, T.; Vicente, D.;
Vogt, S.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler,
M.; Weingrill, K.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal,
M.; Zucker, S.; Zurbach, C.; Zwitter, T.; Alecu, A.; Allen, M.; Allende
Prieto, C.; Amorim, A.; Anglada-Escudé, G.; Arsenijevic, V.; Azaz, S.;
Balm, P.; Beck, M.; Bernstein, H. -H.; Bigot, L.; Bijaoui, A.; Blasco,
C.; Bonfigli, M.; Bono, G.; Boudreault, S.; Bressan, A.; Brown, S.;
Brunet, P. -M.; Bunclark, P.; Buonanno, R.; Butkevich, A. G.; Carret,
C.; Carrion, C.; Chemin, L.; Chéreau, F.; Corcione, L.; Darmigny,
E.; de Boer, K. S.; de Teodoro, P.; de Zeeuw, P. T.; Delle Luche,
C.; Domingues, C. D.; Dubath, P.; Fodor, F.; Frézouls, B.; Fries,
A.; Fustes, D.; Fyfe, D.; Gallardo, E.; Gallegos, J.; Gardiol, D.;
Gebran, M.; Gomboc, A.; Gómez, A.; Grux, E.; Gueguen, A.; Heyrovsky,
A.; Hoar, J.; Iannicola, G.; Isasi Parache, Y.; Janotto, A. -M.;
Joliet, E.; Jonckheere, A.; Keil, R.; Kim, D. -W.; Klagyivik, P.;
Klar, J.; Knude, J.; Kochukhov, O.; Kolka, I.; Kos, J.; Kutka, A.;
Lainey, V.; LeBouquin, D.; Liu, C.; Loreggia, D.; Makarov, V. V.;
Marseille, M. G.; Martayan, C.; Martinez-Rubi, O.; Massart, B.;
Meynadier, F.; Mignot, S.; Munari, U.; Nguyen, A. -T.; Nordlander,
T.; Ocvirk, P.; O'Flaherty, K. S.; Olias Sanz, A.; Ortiz, P.; Osorio,
J.; Oszkiewicz, D.; Ouzounis, A.; Palmer, M.; Park, P.; Pasquato, E.;
Peltzer, C.; Peralta, J.; Péturaud, F.; Pieniluoma, T.; Pigozzi, E.;
Poels, J.; Prat, G.; Prod'homme, T.; Raison, F.; Rebordao, J. M.;
Risquez, D.; Rocca-Volmerange, B.; Rosen, S.; Ruiz-Fuertes, M. I.;
Russo, F.; Sembay, S.; Serraller Vizcaino, I.; Short, A.; Siebert,
A.; Silva, H.; Sinachopoulos, D.; Slezak, E.; Soffel, M.; Sosnowska,
D.; Straižys, V.; ter Linden, M.; Terrell, D.; Theil, S.; Tiede,
C.; Troisi, L.; Tsalmantza, P.; Tur, D.; Vaccari, M.; Vachier, F.;
Valles, P.; Van Hamme, W.; Veltz, L.; Virtanen, J.; Wallut, J. -M.;
Wichmann, R.; Wilkinson, M. I.; Ziaeepour, H.; Zschocke, S.
2016A&A...595A...2G Altcode: 2016arXiv160904172G
Context. At about 1000 days after the launch of Gaia we present
the first Gaia data release, Gaia DR1, consisting of astrometry and
photometry for over 1 billion sources brighter than magnitude 20.7. <BR
/> Aims: A summary of Gaia DR1 is presented along with illustrations
of the scientific quality of the data, followed by a discussion of
the limitations due to the preliminary nature of this release. <BR />
Methods: The raw data collected by Gaia during the first 14 months of
the mission have been processed by the Gaia Data Processing and Analysis
Consortium (DPAC) and turned into an astrometric and photometric
catalogue. <BR /> Results: Gaia DR1 consists of three components: a
primary astrometric data set which contains the positions, parallaxes,
and mean proper motions for about 2 million of the brightest stars
in common with the Hipparcos and Tycho-2 catalogues - a realisation
of the Tycho-Gaia Astrometric Solution (TGAS) - and a secondary
astrometric data set containing the positions for an additional 1.1
billion sources. The second component is the photometric data set,
consisting of mean G-band magnitudes for all sources. The G-band light
curves and the characteristics of 3000 Cepheid and RR Lyrae stars,
observed at high cadence around the south ecliptic pole, form the third
component. For the primary astrometric data set the typical uncertainty
is about 0.3 mas for the positions and parallaxes, and about 1 mas
yr<SUP>-1</SUP> for the proper motions. A systematic component of 0.3
mas should be added to the parallax uncertainties. For the subset of
94 000 Hipparcos stars in the primary data set, the proper motions are
much more precise at about 0.06 mas yr<SUP>-1</SUP>. For the secondary
astrometric data set, the typical uncertainty of the positions is 10
mas. The median uncertainties on the mean G-band magnitudes range from
the mmag level to 0.03 mag over the magnitude range 5 to 20.7. <BR />
Conclusions: Gaia DR1 is an important milestone ahead of the next Gaia
data release, which will feature five-parameter astrometry for all
sources. Extensive validation shows that Gaia DR1 represents a major
advance in the mapping of the heavens and the availability of basic
stellar data that underpin observational astrophysics. Nevertheless,
the very preliminary nature of this first Gaia data release does lead
to a number of important limitations to the data quality which should
be carefully considered before drawing conclusions from the data.
---------------------------------------------------------
Title: Abundances in a sample of turnoff and subgiant stars in NGC
6121 (M 4)
Authors: Spite, M.; Spite, F.; Gallagher, A. J.; Monaco, L.; Bonifacio,
P.; Caffau, E.; Villanova, S.
2016A&A...594A..79S Altcode: 2016arXiv160803541S
Context. The stellar abundances observed in globular clusters show
complex structures, currently not yet understood. <BR /> Aims: The aim
of this work is to investigate the relations between the abundances
of different elements in the globular cluster M 4, selected for its
uniform deficiency of iron, to explore the best models explaining the
pattern of these observed abundances. Moreover, in turnoff stars, the
abundances of the elements are not suspected to be affected by internal
mixing. <BR /> Methods: In M 4, using low and moderate resolution
spectra obtained for 91 turnoff (and subgiant) stars with the ESO
FLAMES-Giraffe spectrograph, we have extended previous measurements of
abundances (of Li, C and Na) to other elements (C, Si, Ca, Sr and Ba),
using model atmosphere analysis. We have also studied the influence of
the choice of the microturbulent velocity. <BR /> Results: Firstly,
the peculiar turnoff star found to be very Li-rich in a previous
paper does not show any other abundance anomalies relative to the
other turnoff stars in M 4. Secondly, an anti-correlation between C
and Na has been detected, the slope being significative at more than
3σ. This relation between C and Na is in perfect agreement with the
relation found in giant stars selected below the RGB bump. Thirdly,
the strong enrichment of Si and of the neutron-capture elements Sr
and Ba, already observed in the giants in M 4, is confirmed. Finally,
the relations between Li, C, Na, Sr and Ba constrain the enrichment
processes of the observed stars. <BR /> Conclusions: The abundances
of the elements in the turnoff stars appear to be compatible with
production processes by massive AGBs, but are also compatible with the
production of second generation elements (like Na) and low Li produced
by, for example, fast rotating massive stars. <P />Based on observations
collected at the European Organisation for Astronomical Research
in the Southern Hemisphere under ESO programme 085.D-0537(A).Full
Tables 3 and 4 are only available at the CDS via anonymous ftp to
<A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(<A href="http://130.79.128.5">http://130.79.128.5</A>) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/594/A79">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/594/A79</A>
---------------------------------------------------------
Title: TOPoS. III. An ultra iron-poor multiple CEMP system
Authors: Caffau, E.; Bonifacio, P.; Spite, M.; Spite, F.; Monaco, L.;
Sbordone, L.; François, P.; Gallagher, A. J.; Plez, B.; Zaggia, S.;
Ludwig, H. -G.; Cayrel, R.; Koch, A.; Steffen, M.; Salvadori, S.;
Klessen, R.; Glover, S.; Christlieb, N.
2016A&A...595L...6C Altcode: 2016arXiv161004106C
<BR /> Aims: One of the primary objectives of the TOPoS survey
is to search for the most metal-poor stars. Our search has led
to the discovery of one of the most iron-poor objects known, SDSS
J092912.32+023817.0. This object is a multiple system, in which two
components are clearly detected in the spectrum. <BR /> Methods:
We have analysed 16 high-resolution spectra obtained using the UVES
spectrograph at the ESO 8.2 m VLT telescope to measure radial velocities
and determine the chemical composition of the system. <BR /> Results:
Cross correlation of the spectra with a synthetic template yields a
double-peaked cross-correlation function (CCF) for eight spectra, and
in one case there is evidence for the presence of a third peak. Chemical
analysis of the spectrum obtained by averaging all the spectra for which
the CCF showed a single peak found that the iron abundance is [Fe/H] =
-4.97. The system is also carbon enhanced with [C/Fe] = +3.91 (A(C) =
7.44). From the permitted oxygen triplet we determined an upper limit
for oxygen of [O/Fe] < +3.52 such that C/O > 1.3. We are also
able to provide more stringent upper limits on the Sr and Ba abundances
([Sr/Fe] < +0.70, and [Ba/Fe] < +1.46, respectively). <P />Based
on observations made with ESO Telescopes at the La Silla Paranal
Observatory under programme ID 094.D-0488 and 096.D-0616.
---------------------------------------------------------
Title: A new algorithm for optimizing the wavelength coverage for
spectroscopic studies: Spectral Wavelength Optimization Code (SWOC)
Authors: Ruchti, G. R.; Feltzing, S.; Lind, K.; Caffau, E.; Korn,
A. J.; Schnurr, O.; Hansen, C. J.; Koch, A.; Sbordone, L.; de Jong,
R. S.
2016MNRAS.461.2174R Altcode: 2016MNRAS.tmp.1006R; 2016arXiv160600833R
The past decade and a half has seen the design and execution
of several ground-based spectroscopic surveys, both Galactic and
Extragalactic. Additionally, new surveys are being designed that extend
the boundaries of current surveys. In this context, many important
considerations must be done when designing a spectrograph for the
future. Among these is the determination of the optimum wavelength
coverage. In this work, we present a new code for determining the
wavelength ranges that provide the optimal amount of information to
achieve the required science goals for a given survey. In its first
mode, it utilizes a user-defined list of spectral features to compute a
figure-of-merit for different spectral configurations. The second mode
utilizes a set of flux-calibrated spectra, determining the spectral
regions that show the largest differences among the spectra. Our
algorithm is easily adaptable for any set of science requirements and
any spectrograph design. We apply the algorithm to several examples,
including 4MOST, showing the method yields important design constraints
to the wavelength regions.
---------------------------------------------------------
Title: An in-depth spectroscopic examination of molecular bands from
3D hydrodynamical model atmospheres. I. Formation of the G-band in
metal-poor dwarf stars
Authors: Gallagher, A. J.; Caffau, E.; Bonifacio, P.; Ludwig, H. -G.;
Steffen, M.; Spite, M.
2016A&A...593A..48G Altcode: 2016arXiv160507215G
Context. Recent developments in the three-dimensional (3D) spectral
synthesis code Linfor3D have meant that for the first time, large
spectral wavelength regions, such as molecular bands, can be synthesised
with it in a short amount of time. <BR /> Aims: A detailed spectral
analysis of the synthetic G-band for several dwarf turn-off-type 3D
atmospheres (5850 ≲ T<SUB>eff</SUB> [ K ] ≲ 6550, 4.0 ≤ log g
≤ 4.5, - 3.0 ≤ [Fe/H] ≤-1.0) was conducted, under the assumption
of local thermodynamic equilibrium. We also examine carbon and oxygen
molecule formation at various metallicity regimes and discuss the impact
it has on the G-band. <BR /> Methods: Using a qualitative approach,
we describe the different behaviours between the 3D atmospheres and
the traditional one-dimensional (1D) atmospheres and how the different
physics involved inevitably leads to abundance corrections, which
differ over varying metallicities. Spectra computed in 1D were fit to
every 3D spectrum to determine the 3D abundance correction. <BR />
Results: Early analysis revealed that the CH molecules that make up
the G-band exhibited an oxygen abundance dependency; a higher oxygen
abundance leads to weaker CH features. Nitrogen abundances showed zero
impact to CH formation. The 3D corrections are also stronger at lower
metallicity. Analysis of the 3D corrections to the G-band allows us to
assign estimations of the 3D abundance correction to most dwarf stars
presented in the literature. <BR /> Conclusions: The 3D corrections
suggest that A(C) in carbon-enhanced metal-poor (CEMP) stars with high
A(C) would remain unchanged, but would decrease in CEMP stars with lower
A(C). It was found that the C/O ratio is an important parameter to the
G-band in 3D. Additional testing confirmed that the C/O ratio is an
equally important parameter for OH transitions under 3D. This presents
a clear interrelation between the carbon and oxygen abundances in 3D
atmospheres through their molecular species, which is not seen in 1D.
---------------------------------------------------------
Title: VizieR Online Data Catalog: NGC 6121 turnoff and subgiant
stars abundances (Spite+, 2016)
Authors: Spite, M.; Spite, F.; Gallagher, A. J.; Monaco, L.; Bonifacio,
P.; Caffau, E.; Villanova, S.
2016yCat..35940079S Altcode:
Observations were conducted at the Very Large Telescope (VLT)
(Paranal, Chile) between April and July 2010 using the LR2 setting
from 400 to 456nm with a resolving power R=6000, the HR12 setting
from 583 to 614nm, and the HR15N setting from 666 to 679nm, both with
a resolving power of about R=20000. The frames were processed using
the FLAMES-GIRAFFE reduction pipeline. More information can be found
in Monaco et al. (2012A&A...539A.157M, Cat. J/A+A/539/A157). The
spectroscopic data are available through the Giraffe archive at Paris
Observatory (http://giraffe-archive.obspm.fr/). <P />(2 data files).
---------------------------------------------------------
Title: Investigation of the lithium 670.7 nm wavelength range in
the solar spectrum
Authors: Caffau, Elisabetta; Mott, Alessandro; Harutyunyan, Gohar;
Malherbe, Jean-Marie; Steffen, Matthias
2016cosp...41E.281C Altcode:
Lithium is a key chemical element, with a chemical evolution that is
different from that of most other elements. It is also very fragile,
as it is destroyed by nuclear reactions with protons at temperatures
higher than about 2.5 million K. According to standard Big Bang
nucleosynthesis, only the isotope 7Li is produced in significant
amounts, while the primordial abundance of the lighter isotope 6Li
is negligible. Lithium is not produced by nucleosynthesis in normal
stars, except in peculiar phases of stellar evolution (e.g. in AGB
stars and Novae). Lithium may also be formed as a result of flares in
the atmospheres of young, active stars. To investigate the history
of Li production and depletion in the Galaxy, it is necessary to
analyse stars of all ages, including those at solar metallicity. In
this case, the spectroscopic determination of the Li abundance is
complicated by the presence of other spectral lines overlapping
with the Li doublet at 670.7 nm. The correct identification and
knowledge of the atomic parameters of these blend lines is critical,
especially if the 6LI/7Li isotopic ratio is to be derived. In this
investigation, we consider several line lists of the blending components
available in the literature and use them to compute synthetic spectra,
performing the line formation computations both for the classical 1D
Holweger-Mueller model and a CO5BOLD 3D hydrodynamical simulation of the
solar atmosphere. The synthetic spectra are then compared to the solar
spectrum observed at different limb angles. This allows us to check the
quality of existing line lists, to find potentially misidentified blend
lines, and to construct an optimized line list for solar-type stars.
---------------------------------------------------------
Title: A concise overview of the Maunakea Spectroscopic Explorer
Authors: McConnachie, Alan W.; Babusiaux, Carine; Balogh, Michael;
Caffau, Elisabetta; Côté, Pat; Driver, Simon; Robotham, Aaron;
Starkenburg, Else; Venn, Kim; Walker, Matthew; Bauman, Steven E.;
Flagey, Nicolas; Ho, Kevin; Isani, Sidik; Laychak, Mary Beth; Mignot,
Shan; Murowinski, Rick; Salmon, Derrick; Simons, Doug; Szeto, Kei;
Vermeulen, Tom; Withington, Kanoa
2016arXiv160600060M Altcode:
This short document is intended as a companion and introduction to the
Detailed Science Case (DSC) for the Maunakea Spectroscopic Explorer. It
provides a concise summary of the essential characteristics of MSE
from the perspective of the international astronomical community. MSE
is a wide field telescope (1.5 square degree field of view) with an
aperture of 11.25m. It is dedicated to multi-object spectroscopy at
several different spectral resolutions in the range R ~ 2500 - 40000
over a broad wavelength range (0.36 - 1.8{\mu}m). MSE will enable
transformational science in areas as diverse as exoplanetary host
characterization; stellar monitoring campaigns; tomographic mapping
of the interstellar and intergalactic media; the in-situ chemical
tagging of the distant Galaxy; connecting galaxies to the large scale
structure of the Universe; measuring the mass functions of cold dark
matter sub-halos in galaxy and cluster-scale hosts; reverberation
mapping of supermassive black holes in quasars. MSE is the largest
ground based optical and near infrared telescope in its class, and
it will occupy a unique and critical role in the emerging network
of astronomical facilities active in the 2020s. MSE is an essential
follow-up facility to current and next generations of multi-wavelength
imaging surveys, including LSST, Gaia, Euclid, eROSITA, SKA, and WFIRST,
and is an ideal feeder facility for E-ELT, TMT and GMT.
---------------------------------------------------------
Title: The Detailed Science Case for the Maunakea Spectroscopic
Explorer: the Composition and Dynamics of the Faint Universe
Authors: McConnachie, Alan; Babusiaux, Carine; Balogh, Michael; Driver,
Simon; Côté, Pat; Courtois, Helene; Davies, Luke; Ferrarese, Laura;
Gallagher, Sarah; Ibata, Rodrigo; Martin, Nicolas; Robotham, Aaron;
Venn, Kim; Villaver, Eva; Bovy, Jo; Boselli, Alessandro; Colless,
Matthew; Comparat, Johan; Denny, Kelly; Duc, Pierre-Alain; Ellison,
Sara; de Grijs, Richard; Fernandez-Lorenzo, Mirian; Freeman, Ken;
Guhathakurta, Raja; Hall, Patrick; Hopkins, Andrew; Hudson, Mike;
Johnson, Andrew; Kaiser, Nick; Koda, Jun; Konstantopoulos, Iraklis;
Koshy, George; Lee, Khee-Gan; Nusser, Adi; Pancoast, Anna; Peng, Eric;
Peroux, Celine; Petitjean, Patrick; Pichon, Christophe; Poggianti,
Bianca; Schmid, Carlo; Shastri, Prajval; Shen, Yue; Willot, Chris;
Croom, Scott; Lallement, Rosine; Schimd, Carlo; Smith, Dan; Walker,
Matthew; Willis, Jon; Colless, Alessandro Bosselli Matthew; Goswami,
Aruna; Jarvis, Matt; Jullo, Eric; Kneib, Jean-Paul; Konstantopoloulous,
Iraklis; Newman, Jeff; Richard, Johan; Sutaria, Firoza; Taylor,
Edwar; van Waerbeke, Ludovic; Battaglia, Giuseppina; Hall, Pat;
Haywood, Misha; Sakari, Charli; Schmid, Carlo; Seibert, Arnaud;
Thirupathi, Sivarani; Wang, Yuting; Wang, Yiping; Babas, Ferdinand;
Bauman, Steve; Caffau, Elisabetta; Laychak, Mary Beth; Crampton,
David; Devost, Daniel; Flagey, Nicolas; Han, Zhanwen; Higgs, Clare;
Hill, Vanessa; Ho, Kevin; Isani, Sidik; Mignot, Shan; Murowinski,
Rick; Pandey, Gajendra; Salmon, Derrick; Siebert, Arnaud; Simons,
Doug; Starkenburg, Else; Szeto, Kei; Tully, Brent; Vermeulen, Tom;
Withington, Kanoa; Arimoto, Nobuo; Asplund, Martin; Aussel, Herve;
Bannister, Michele; Bhatt, Harish; Bhargavi, SS; Blakeslee, John;
Bland-Hawthorn, Joss; Bullock, James; Burgarella, Denis; Chang,
Tzu-Ching; Cole, Andrew; Cooke, Jeff; Cooper, Andrew; Di Matteo, Paola;
Favole, Ginevra; Flores, Hector; Gaensler, Bryan; Garnavich, Peter;
Gilbert, Karoline; Gonzalez-Delgado, Rosa; Guhathakurta, Puragra;
Hasinger, Guenther; Herwig, Falk; Hwang, Narae; Jablonka, Pascale;
Jarvis, Matthew; Kamath, Umanath; Kewley, Lisa; Le Borgne, Damien;
Lewis, Geraint; Lupton, Robert; Martell, Sarah; Mateo, Mario; Mena,
Olga; Nataf, David; Newman, Jeffrey; Pérez, Enrique; Prada, Francisco;
Puech, Mathieu; Recio-Blanco, Alejandra; Robin, Annie; Saunders, Will;
Smith, Daniel; Stalin, C. S.; Tao, Charling; Thanjuvur, Karun; Tresse,
Laurence; van Waerbeke, Ludo; Wang, Jian-Min; Yong, David; Zhao,
Gongbo; Boisse, Patrick; Bolton, James; Bonifacio, Piercarlo; Bouchy,
Francois; Cowie, Len; Cunha, Katia; Deleuil, Magali; de Mooij, Ernst;
Dufour, Patrick; Foucaud, Sebastien; Glazebrook, Karl; Hutchings,
John; Kobayashi, Chiaki; Kudritzki, Rolf-Peter; Li, Yang-Shyang;
Lin, Lihwai; Lin, Yen-Ting; Makler, Martin; Narita, Norio; Park,
Changbom; Ransom, Ryan; Ravindranath, Swara; Eswar Reddy, Bacham;
Sawicki, Marcin; Simard, Luc; Srianand, Raghunathan; Storchi-Bergmann,
Thaisa; Umetsu, Keiichi; Wang, Ting-Gui; Woo, Jong-Hak; Wu, Xue-Bing
2016arXiv160600043M Altcode:
MSE is an 11.25m aperture observatory with a 1.5 square degree field of
view that will be fully dedicated to multi-object spectroscopy. More
than 3200 fibres will feed spectrographs operating at low (R ~ 2000 -
3500) and moderate (R ~ 6000) spectral resolution, and approximately
1000 fibers will feed spectrographs operating at high (R ~ 40000)
resolution. MSE is designed to enable transformational science in areas
as diverse as tomographic mapping of the interstellar and intergalactic
media; the in-situ chemical tagging of thick disk and halo stars;
connecting galaxies to their large scale structure; measuring the mass
functions of cold dark matter sub-halos in galaxy and cluster-scale
hosts; reverberation mapping of supermassive black holes in quasars;
next generation cosmological surveys using redshift space distortions
and peculiar velocities. MSE is an essential follow-up facility to
current and next generations of multi-wavelength imaging surveys,
including LSST, Gaia, Euclid, WFIRST, PLATO, and the SKA, and is
designed to complement and go beyond the science goals of other planned
and current spectroscopic capabilities like VISTA/4MOST, WHT/WEAVE,
AAT/HERMES and Subaru/PFS. It is an ideal feeder facility for E-ELT, TMT
and GMT, and provides the missing link between wide field imaging and
small field precision astronomy. MSE is optimized for high throughput,
high signal-to-noise observations of the faintest sources in the
Universe with high quality calibration and stability being ensured
through the dedicated operational mode of the observatory. (abridged)
---------------------------------------------------------
Title: Lithium spectral line formation in stellar atmospheres. The
impact of convection and NLTE effects
Authors: Klevas, J.; Kučinskas, A.; Steffen, M.; Caffau, E.; Ludwig,
H. -G.
2016A&A...586A.156K Altcode: 2015arXiv151208999K
<BR /> Aims: Because of the complexities involved in treating
spectral line formation in full 3D and non-local thermodynamic
equilibrium (NLTE), different simplified approaches are sometimes
used to account for the NLTE effects with 3D hydrodynamical model
atmospheres. In certain cases, chemical abundances are derived in
1D NLTE and then corrected for the 3D effects by adding 3D-1D LTE
(Local Thermodynamic Equilibrium, LTE) abundance corrections (3D+NLTE
approach). Alternatively, average ⟨3D⟩ model atmospheres are
sometimes used to substitute for the full 3D hydrodynamical models. <BR
/> Methods: In this work we tested whether the results obtained using
these simplified schemes (3D+NLTE, ⟨3D⟩ NLTE) may reproduce those
derived using the full 3D NLTE computations. The tests were made using
3D hydrodynamical CO<SUP>5</SUP>BOLD model atmospheres of the main
sequence (MS), main sequence turn-off (TO), subgiant (SGB), and red
giant branch (RGB) stars, all at two metallicities, [ M / H ] = 0.0
and -2.0. Our goal was to investigate the role of 3D and NLTE effects
on the formation of the 670.8 nm lithium resonance line. This was done
by assessing differences in the strengths of synthetic 670.8 nm line
profiles, which were computed using 3D/1D NLTE/LTE approaches. <BR />
Results: Our results show that Li 670.8 nm line strengths obtained
using different methodologies differ only slightly in most of the
models at solar metallicity studied here. However, the line strengths
predicted with the 3D NLTE and 3D+NLTE approaches become significantly
different at subsolar metallicities. At [ M / H ] = -2.0, this may lead
to (3D NLTE) - (3D+NLTE) differences in the predicted lithium abundance
of ~0.46 and ~0.31 dex in the TO and RGB stars respectively. On the
other hand, NLTE line strengths computed with the average ⟨3D⟩ and
1D model atmospheres are similar to those obtained with the full 3D
NLTE approach for MS, TO, SGB, and RGB stars, at all metallicities;
3D - ⟨3D⟩ and 3D - 1D differences in the predicted abundances
are always less than ~0.04 dex and ~0.08 dex, respectively. However,
neither of the simplified approaches can reliably substitute 3D NLTE
spectral synthesis when precision is required.
---------------------------------------------------------
Title: GIANO Y-band spectroscopy of dwarf stars: Phosphorus, sulphur,
and strontium abundances
Authors: Caffau, E.; Andrievsky, S.; Korotin, S.; Origlia, L.; Oliva,
E.; Sanna, N.; Ludwig, H. -G.; Bonifacio, P.
2016A&A...585A..16C Altcode: 2015arXiv151006396C
Context. In recent years a number of poorly studied chemical elements,
such as phosphorus, sulphur, and strontium, have received special
attention as important tracers of the Galactic chemical evolution. <BR
/> Aims: By exploiting the capabilities of the infrared echelle
spectrograph GIANO mounted at the Telescopio Nazionale Galileo,
we acquired high resolution spectra of four Galactic dwarf stars
spanning the metallicity range between about one-third and twice
the solar value. We performed a detailed feasibility study about
the effectiveness of the P, S, and Sr line diagnostics in the Y band
between 1.03 and 1.10 μm. <BR /> Methods: Accurate chemical abundances
have been derived using one-dimensional model atmospheres computed in
local thermodynamic equilibrium (LTE). We computed the line formation
assuming LTE for P, while we performed non-LTE analysis to derive S
and Sr abundances. <BR /> Results: We were able to derive phosphorus
abundance for three stars and an upper limit for one star, while we
obtained the abundance of sulphur and strontium for all of the stars. We
find [P/Fe] and [S/Fe] abundance ratios consistent with solar-scaled
or slightly depleted values, while the [Sr/Fe] abundance ratios are
more scattered (by ±0.2 dex) around the solar-scaled value. This is
fully consistent with previous studies using both optical and infrared
spectroscopy. <BR /> Conclusions: We verified that high-resolution,
Y-band spectroscopy as provided by GIANO is a powerful tool to study
the chemical evolution of P, S, and Sr in dwarf stars. <P />Based on
observations obtained with GIANO.
---------------------------------------------------------
Title: HST/STIS abundances in the uranium rich metal poor star CS
31082-001: Constraints on the r-Process
Authors: Siqueira-Mello, C.; Spite, M.; Barbuy, B.; Spite, F.; Caffau,
E.; Hill, V.; Wanajo, S.; Primas, F.; Plez, B.; Cayrel, R.; Andersen,
J.; Nordström, B.; Sneden, C.; Beers, T. C.; Bonifacio, P.; François,
P.; Molaro, P.
2016JPhCS.665a2056S Altcode:
As a brief revision, the origin of heavy elements and the role of
abundances in extremely metal-poor (EMP) stars are presented. Heavy
element abundances in the EMP uranium-rich star CS 31082-001
based mainly on near-UV spectra from STIS/HST are presented. These
results should be useful for a better characterisation of the neutron
exposure(s) that produced the r-process elements in this star, as well
as a guide for improving nuclear data and astrophysical site modelling,
given that the new element abundances not available in previous works
(Ge, Mo, Lu, Ta, W, Re, Pt, Au, and Bi) make CS 31082-001 the most
completely well studied r-II object, with a total of 37 detections of
n-capture elements.
---------------------------------------------------------
Title: Chemical composition of a sample of bright solar-metallicity
stars
Authors: Caffau, E.; Mott, A.; Steffen, M.; Bonifacio, P.; Strassmeier,
K. G.; Gallagher, A.; Faraggiana, R.; Sbordone, L.
2015AN....336..968C Altcode: 2015arXiv151004269C
We present a detailed analysis of seven young stars observed with the
spectrograph SOPHIE at the Observatoire de Haute-Provence for which the
chemical composition was incomplete or absent in the literature. For
five stars, we derived the stellar parameters and chemical compositions
using our automatic pipeline optimized for F, G, and K stars, while
for the other two stars with high rotational velocity, we derived the
stellar parameters by using other information (parallax), and performed
a line-by-line analysis. Chromospheric emission-line fluxes from Ca
II are obtained for all targets. The stellar parameters we derive are
generally in good agreement with what is available in the literature. We
provide a chemical analysis of two of the stars for the first time. The
star HIP 80124 shows a strong Li feature at 670.8 nm implying a high
lithium abundance. Its chemical pattern is not consistent with it
being a solar sibling, as has been suggested. <P />Data obtained at
Observatoire de Haute Provence, with the SOPHIE spectrograph.
---------------------------------------------------------
Title: The photospheric solar oxygen project. IV. 3D-NLTE
investigation of the 777 nm triplet lines
Authors: Steffen, M.; Prakapavičius, D.; Caffau, E.; Ludwig, H. -G.;
Bonifacio, P.; Cayrel, R.; Kučinskas, A.; Livingston, W. C.
2015A&A...583A..57S Altcode: 2015arXiv150803487S
Context. The solar photospheric oxygen abundance is still widely
debated. Adopting the solar chemical composition based on the "low"
oxygen abundance, as determined with the use of three-dimensional (3D)
hydrodynamical model atmospheres, results in a well-known mismatch
between theoretical solar models and helioseismic measurements
that is so far unresolved. <BR /> Aims: We carry out an independent
redetermination of the solar oxygen abundance by investigating the
center-to-limb variation of the O i IR triplet lines at 777 nm in
different sets of spectra. <BR /> Methods: The high-resolution and high
signal-to-noise solar center-to-limb spectra are analyzed with the
help of detailed synthetic line profiles based on 3D hydrodynamical
CO5BOLD model atmospheres and 3D non-LTE line formation calculations
with NLTE3D. The idea is to exploit the information contained in the
observations at different limb angles to simultaneously derive the
oxygen abundance, A(O), and the scaling factor S<SUB>H</SUB> that
describes the cross-sections for inelastic collisions with neutral
hydrogen relative to the classical Drawin formula. Using the same
codes and methods, we compare our 3D results with those obtained from
the semi-empirical Holweger-Müller model atmosphere as well as from
different one-dimensional (1D) reference models. <BR /> Results: With
the CO5BOLD 3D solar model, the best fit of the center-to-limb variation
of the triplet lines is obtained when the collisions by neutral hydrogen
atoms are assumed to be efficient, i.e., when the scaling factor
S<SUB>H</SUB> is between 1.2 and 1.8, depending on the choice of the
observed spectrum and the triplet component used in the analysis. The
line profile fits achieved with standard 1D model atmospheres (with
fixed microturbulence, independent of disk position μ) are clearly
of inferior quality compared to the 3D case, and give the best match
to the observations when ignoring collisions with neutral hydrogen
(S<SUB>H</SUB> = 0). The results derived with the Holweger-Müller model
are intermediate between 3D and standard 1D. <BR /> Conclusions: The
analysis of various observations of the triplet lines with different
methods yields oxygen abundance values (on a logarithmic scale where
A(H) = 12) that fall in the range 8.74 <A(O) < 8.78, and our
best estimate of the 3D non-LTE solar oxygen abundance is A(O) = 8.76
± 0.02. All 1D non-LTE models give much lower oxygen abundances,
by up to -0.15 dex. This is mainly a consequence of the assumption
of a μ-independent microturbulence. An independent determination of
the relevant collisional cross-sections is essential to substantially
improve the accuracy of the oxygen abundance derived from the O i IR
triplet. <P />Appendices E and F are available in electronic form at <A
href="http://www.aanda.org/10.1051/0004-6361/201526406/olm">http://www.aanda.org</A>
---------------------------------------------------------
Title: Surface-effect corrections for solar-like oscillations using
3D hydrodynamical simulations. I. Adiabatic oscillations
Authors: Sonoi, T.; Samadi, R.; Belkacem, K.; Ludwig, H. -G.; Caffau,
E.; Mosser, B.
2015A&A...583A.112S Altcode: 2015arXiv151000300S
Context. The CoRoT and Kepler space-borne missions have provided us with
a wealth of high-quality observational data that allows for seismic
inferences of stellar interiors. This requires the computation of
precise and accurate theoretical frequencies, but imperfect modeling of
the uppermost stellar layers introduces systematic errors. To overcome
this problem, an empirical correction has been introduced by Kjeldsen
et al. (2008, ApJ, 683, L175) and is now commonly used for seismic
inferences. Nevertheless, we still lack a physical justification
allowing for the quantification of the surface-effect corrections. <BR
/> Aims: Our aim is to constrain the surface-effect corrections across
the Hertzsprung-Russell (HR) diagram using a set of 3D hydrodynamical
simulations. <BR /> Methods: We used a grid of these simulations
computed with the CO<SUP>5</SUP>BOLD code to model the outer layers of
solar-like stars. Upper layers of the corresponding 1D standard models
were then replaced by the layers obtained from the horizontally averaged
3D models. The frequency differences between these patched models
and the 1D standard models were then calculated using the adiabatic
approximation and allowed us to constrain the Kjeldsen et al. power law,
as well as a Lorentzian formulation. <BR /> Results: We find that the
surface effects on modal frequencies depend significantly on both the
effective temperature and the surface gravity. We further provide the
variation in the parameters related to the surface-effect corrections
using their power law as well as a Lorentzian formulation. Scaling
relations between these parameters and the elevation (related to the
Mach number) is also provided. The Lorentzian formulation is shown to
be more robust for the whole frequency spectrum, while the power law
is not suitable for the frequency shifts in the frequency range above
ν<SUB>max</SUB>. Finally, we show that, owing to turbulent pressure,
the elevation of the uppermost layers modifies the location of the
hydrogen ionization zone and consequently introduces glitches in
the surface effects for models with high (low) effective temperature
(surface gravity). <BR /> Conclusions: Surface-effect corrections vary
significantly across the HR diagram. Therefore, empirical relations
like those by Kjeldsen et al. must not be calibrated on the Sun but
should instead be constrained using realistic physical modeling as
provided by 3D hydrodynamical simulations.
---------------------------------------------------------
Title: Lithium abundance in a turnoff halo star on an extreme orbit
Authors: Spite, M.; Spite, F.; Caffau, E.; Bonifacio, P.
2015A&A...582A..74S Altcode: 2015arXiv150907809S
Context. The lithium abundance in turnoff stars of the old population
of our Galaxy is remarkably constant in the metallicity interval
-2.8 < [Fe/H] < -2.0, defining a plateau. The Li abundance of
these turnoff stars is clearly lower than the abundance predicted
by the primordial nucleosynthesis in the frame of the standard Big
Bang nucleosynthesis. Different scenarios have been proposed for
explaining this discrepancy, along with the very low scatter of the
lithium abundance around the plateau. <BR /> Aims: The recently
identified very high velocity star, WISE J0725-2351 appears to
belong to the old Galactic population, and appears to be an extreme
halo star on a bound, retrograde Galactic orbit. In this paper, we
study the abundance ratios and, in particular the lithium abundance,
in this star. <BR /> Methods: The available spectra (ESO-Very Large
Telescope) are analyzed and the abundances of Li, C, Na, Mg, Al,
Si, Ca, Sc, Ti, Cr, Mn, Fe, Co, Ni, Sr and Ba are determined. <BR />
Results: The abundance ratios in WISE J0725-2351 are those typical
of old turnoff stars. The lithium abundance in this star is in close
agreement with the lithium abundance found in the metal-poor turnoff
stars located at moderate distance from the Sun. This high velocity
star confirms, in an extreme case, that the very small scatter of
the lithium plateau persists independent of the dynamic and kinematic
properties of the stars. <P />Based on observations obtained at the
ESO Paranal Observatory, Chile Programmes 093.D-0127, PI: S. Geier
and 189.B-0925, PI: S. Trager.Table 2 (line by line abundances of
the elements) is only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/582/A74">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/582/A74</A>
---------------------------------------------------------
Title: Grid of theoretical NLTE equivalent widths of four Ba ii
lines and barium abundance in cool stars
Authors: Korotin, S. A.; Andrievsky, S. M.; Hansen, C. J.; Caffau,
E.; Bonifacio, P.; Spite, M.; Spite, F.; François, P.
2015A&A...581A..70K Altcode: 2015arXiv150707472K
Context. We present a grid of computed non-local thermodynamic
equilibrium (NLTE) equivalent widths (EW) and NLTE abundance corrections
for four Ba ii lines: 4554, 5853, 6141, and 6496 Å. <BR /> Aims:
The grid can be useful in deriving the NLTE barium abundance in stars
having parameters in the following ranges: effective temperature from
4000 K to 6500 K, surface gravity log g from 0 to 5, microturbulent
velocity 0 km s<SUP>-1</SUP> to 3 km s<SUP>-1</SUP>, metallicity [Fe/H]
from -2 to +0.5, and [Ba/Fe] from -0.4 to +0.6. The NLTE abundance can
be either derived by EW interpolation (using the observed Ba ii line
EW) or by using the NLTE correction applied to a previously determined
LTE abundance. <BR /> Methods: Ba ii line equivalent widths and the
NLTE corrections were calculated using the updated MULTI code and
the Ba ii atomic model that was previously applied to determine the
NLTE barium abundance in different types of stars. <BR /> Results:
The grid is available on-line through the web, and we find that
the grid Ba NLTE corrections are almost as accurate as direct NLTE
profile fitting (to within 0.05-0.08 dex). For the weakest Ba ii line
(5853 Å) the LTE abundances almost agree with the NLTE abundances,
whereas the other three Ba ii lines, 4554, 6141, and 6496 Å, need
NLTE corrections even at the highest metallicities tested here. The
4554 Å line is extremely strong and should not be used for abundance
analysis above [Fe/H] = -1. Furthermore, we tested the impact of
different model atmospheres and spectrum synthesis codes and found
average differences of 0.06 dex and 0.09 dex, respectively, for all
four lines. At these metallicities we find an average ΔNLTE of ±
0.1 dex for the three useful Ba lines for subsolar cool dwarfs. <P
/>Tables 4 and 5 are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/581/A70">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/581/A70</A>Appendix
A is available in electronic form at <A
href="http://www.aanda.org/10.1051/0004-6361/201526558/olm">http://www.aanda.org</A>
---------------------------------------------------------
Title: Stellar science from a blue wavelength range. A possible
design for the blue arm of 4MOST
Authors: Hansen, C. J.; Ludwig, H. -G.; Seifert, W.; Koch, A.; Xu,
W.; Caffau, E.; Christlieb, N.; Korn, A. J.; Lind, K.; Sbordone, L.;
Ruchti, G.; Feltzing, S.; de Jong, R. S.; Barden, S.
2015AN....336..665H Altcode: 2015arXiv150802714H
From stellar spectra, a variety of physical properties of stars
can be derived. In particular, the chemical composition of stellar
atmospheres can be inferred from absorption line analyses. These
provide key information on large scales, such as the formation of our
Galaxy, down to the small-scale nucleosynthesis processes that take
place in stars and supernovae. By extending the observed wavelength
range toward bluer wavelengths, we optimize such studies to also
include critical absorption lines in metal-poor stars, and allow
for studies of heavy elements (Z\ensuremath{g}e 38) whose formation
processes remain poorly constrained. In this context, spectrographs
optimized for observing blue wavelength ranges are essential, since many
absorption lines at redder wavelengths are too weak to be detected in
metal-poor stars. This means that some elements cannot be studied in
the visual-redder regions, and important scientific tracers and science
cases are lost. The present era of large public surveys will target
millions of stars. It is therefore important that the next generation
of spectrographs are designed such that they cover a wide wavelength
range and can observe a large number of stars simultaneously. Only
then, we can gain the full information from stellar spectra, from
both metal-poor to metal-rich ones, that will allow us to understand
the aforementioned formation scenarios in greater detail. Here we
describe the requirements driving the design of the forthcoming survey
instrument 4MOST, a multi-object spectrograph commissioned for the
ESO VISTA 4 m-telescope. While 4MOST is also intended for studies of
active galactic nuclei, baryonic acoustic oscillations, weak lensing,
cosmological constants, supernovae and other transients, we focus here
on high-density, wide-area survey of stars and the science that can
be achieved with high-resolution stellar spectroscopy. Scientific and
technical requirements that governed the design are described along with
a thorough line blending analysis. For the high-resolution spectrograph,
we find that a sampling of {\ensuremath{g}e 2.5} (pixels per resolving
element), spectral resolution of 18 000 or higher, and a wavelength
range covering 393-436 nm, is the most well-balanced solution for
the instrument. A spectrograph with these characteristics will enable
accurate abundance analysis (± 0.1 dex) in the blue and allow us to
confront the outlined scientific questions.
---------------------------------------------------------
Title: VizieR Online Data Catalog: WISE J072543.88-235119.7 line
abundances (Spite+, 2015)
Authors: Spite, M.; Spite, F.; Caffau, E.; Bonifacio, P.
2015yCat..35820074S Altcode:
Main parameters of the lines and logarithm of the corresponding
abundances for logA(H)=12. <P />(1 data file).
---------------------------------------------------------
Title: VizieR Online Data Catalog: Grid of NLTE EW and NLTE
corrections BaII lines (Korotin+, 2015)
Authors: Korotin, S. A.; Andrievsky, S. M.; Hansen, C. J.; Caffau,
E.; Bonifacio, P.; Spite, M.; Spite, F.; Francois, P.
2015yCat..35810070K Altcode:
The following stellar parameter ranges are covered by our grid, which
focuses on more metal-rich stars (compared to the very metal-poor
and extremely metal-poor stas) that are typically targeted in current
and future surveys: <P />- effective temperature: 4000-6500K, step =
250K; - surface gravity: 0-5, step = 0.5 - microturbulent velocity:
0-3km/s, step = 1km/s; - metallicity: [Fe/H] = +0.5, 0.0, -0.5,
-1.0, -1.5 and -2.0; - relative barium abundance: [Ba/Fe] = -0.40,
-0.20, 0.00, +0.20, +0.40, +0.60. <P />For the models with [Fe/H]
below -1.00 we calculated NLTE equivalent widths with an increased
atmosphere abundance of alpha-elements ([alpha/Fe]=+0.4), while for
a metallicity of -0.5 both cases (solar alpha-element abundance
and an increased one) were considered. <P />The NLTE equivalent
widths of the four barium lines were calculated: 4554, 5853, 6141,
and 6496Å. <P />Tables 4 and 5 contain the NLTE equivalent widths
and NLTE corrections, respectively. For each barium line we selected
six values of [Ba/Fe] (-0.4, -0.2, 0.0, +0.2, +0.4 and +0.6) for
the NLTE EW grid, and three values of [Ba/Fe] (-0.2, 0.1, and +0.4)
for the NLTE correction grid. For each of these values we list in the
corresponding table the EWs or corrections calculated for the full set
of effective temperature, surface gravity, microturbulent velocity,
and metallicity. <P />(2 data files).
---------------------------------------------------------
Title: The photospheric solar oxygen project. III. Investigation of
the centre-to-limb variation of the 630 nm [O I]-Ni I blend
Authors: Caffau, E.; Ludwig, H. -G.; Steffen, M.; Livingston, W.;
Bonifacio, P.; Malherbe, J. -M.; Doerr, H. -P.; Schmidt, W.
2015A&A...579A..88C Altcode: 2015arXiv150600931C
Context. The solar photospheric abundance of oxygen is still a matter
of debate. For about ten years some determinations have favoured a
low oxygen abundance which is at variance with the value inferred by
helioseismology. Among the oxygen abundance indicators, the forbidden
line at 630 nm has often been considered the most reliable even
though it is blended with a Ni i line. In Papers I and II of this
series we reported a discrepancy in the oxygen abundance derived
from the 630 nm and the subordinate [O I] line at 636 nm in dwarf
stars, including the Sun. <BR /> Aims: Here we analyse several,
in part new, solar observations of the centre-to-limb variation
of the spectral region including the blend at 630 nm in order to
separate the individual contributions of oxygen and nickel. <BR />
Methods: We analyse intensity spectra observed at different limb
angles in comparison with line formation computations performed on a
CO5BOLD 3D hydrodynamical simulation of the solar atmosphere. <BR />
Results: The oxygen abundances obtained from the forbidden line at
different limb angles are inconsistent if the commonly adopted nickel
abundance of 6.25 is assumed in our local thermodynamic equilibrium
computations. With a slightly lower nickel abundance, A(Ni) ≈ 6.1,
we obtain consistent fits indicating an oxygen abundance of A(O) = 8.73
± 0.05. At this value the discrepancy with the subordinate oxygen
line remains. <BR /> Conclusions: The derived value of the oxygen
abundance supports the notion of a rather low oxygen abundance in the
solar photosphere. However, it is disconcerting that the forbidden
oxygen lines at 630 and 636 nm give noticeably different results,
and that the nickel abundance derived here from the 630 nm blend is
lower than expected from other nickel lines.
---------------------------------------------------------
Title: TOPoS . II. On the bimodality of carbon abundance in CEMP
stars Implications on the early chemical evolution of galaxies
Authors: Bonifacio, P.; Caffau, E.; Spite, M.; Limongi, M.; Chieffi,
A.; Klessen, R. S.; François, P.; Molaro, P.; Ludwig, H. -G.; Zaggia,
S.; Spite, F.; Plez, B.; Cayrel, R.; Christlieb, N.; Clark, P. C.;
Glover, S. C. O.; Hammer, F.; Koch, A.; Monaco, L.; Sbordone, L.;
Steffen, M.
2015A&A...579A..28B Altcode: 2015arXiv150405963B
Context. In the course of the Turn Off Primordial Stars (TOPoS) survey,
aimed at discovering the lowest metallicity stars, we have found several
carbon-enhanced metal-poor (CEMP) stars. These stars are very common
among the stars of extremely low metallicity and provide important
clues to the star formation processes. We here present our analysis
of six CEMP stars. <BR /> Aims: We want to provide the most complete
chemical inventory for these six stars in order to constrain the
nucleosynthesis processes responsible for the abundance patterns. <BR
/> Methods: We analyse both X-Shooter and UVES spectra acquired at the
VLT. We used a traditional abundance analysis based on OSMARCS 1D local
thermodynamic equilibrium (LTE) model atmospheres and the turbospectrum
line formation code. <BR /> Results: Calcium and carbon are the only
elements that can be measured in all six stars. The range is -5.0 ≤
[Ca/H] <-2.1 and 7.12 ≤ A(C) ≤ 8.65. For star SDSS J1742+2531
we were able to detect three Fe i lines from which we deduced [Fe/H]
= -4.80, from four Ca ii lines we derived [Ca/H] = -4.56, and from
synthesis of the G-band we derived A(C) = 7.26. For SDSS J1035+0641 we
were not able to detect any iron lines, yet we could place a robust
(3σ) upper limit of [Fe/H] < -5.0 and measure the Ca abundance,
with [Ca/H] = -5.0, and carbon, A(C) = 6.90, suggesting that this star
could be even more metal-poor than SDSS J1742+2531. This makes these
two stars the seventh and eighth stars known so far with [Fe/H] <
-4.5, usually termed ultra-iron-poor (UIP) stars. No lithium is detected
in the spectrum of SDSS J1742+2531 or SDSS J1035+0641, which implies a
robust upper limit of A(Li) < 1.8 for both stars. <BR /> Conclusions:
Our measured carbon abundances confirm the bimodal distribution of
carbon in CEMP stars, identifying a high-carbon band and a low-carbon
band. We propose an interpretation of this bimodality according to which
the stars on the high-carbon band are the result of mass transfer from
an AGB companion, while the stars on the low-carbon band are genuine
fossil records of a gas cloud that has also been enriched by a faint
supernova (SN) providing carbon and the lighter elements. The abundance
pattern of the UIP stars shows a large star-to-star scatter in the
[X/Ca] ratios for all elements up to aluminium (up to 1 dex), but
this scatter drops for heavier elements and is at most of the order
of a factor of two. We propose that this can be explained if these
stars are formed from gas that has been chemically enriched by several
SNe, that produce the roughly constant [X/Ca] ratios for the heavier
elements, and in some cases the gas has also been polluted by the
ejecta of a faint SN that contributes the lighter elements in variable
amounts. The absence of lithium in four of the five known unevolved
UIP stars can be explained by a dominant role of fragmentation in the
formation of these stars. This would result either in a destruction
of lithium in the pre-main-sequence phase, through rotational mixing
or to a lack of late accretion from a reservoir of fresh gas. The
phenomenon should have varying degrees of efficiency. <P />Based on
observations obtained at ESO Paranal Observatory, programme 091.D-0288,
091.D-0305, 189.D-0165.Appendix A is available in electronic form at <A
href="http://www.aanda.org/10.1051/0004-6361/201425266/olm">http://www.aanda.org</A>Tables
4 is only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/579/A28">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/579/A28</A>
---------------------------------------------------------
Title: Chemical abundances of giant stars in <ASTROBJ>NGC
5053</ASTROBJ> and <ASTROBJ>NGC 5634</ASTROBJ>, two globular clusters
associated with the Sagittarius dwarf spheroidal galaxy?
Authors: Sbordone, L.; Monaco, L.; Moni Bidin, C.; Bonifacio, P.;
Villanova, S.; Bellazzini, M.; Ibata, R.; Chiba, M.; Geisler, D.;
Caffau, E.; Duffau, S.
2015A&A...579A.104S Altcode: 2015arXiv150501487S
Context. The tidal disruption of the Sagittarius dwarf spheroidal galaxy
(Sgr dSph) is producing the most prominent substructure in the Milky
Way (MW) halo, the Sagittarius Stream. Aside from field stars, it is
suspected that the Sgr dSph has lost a number of globular clusters
(GC). Many Galactic GC are thought to have originated in the Sgr
dSph. While for some candidates an origin in the Sgr dSph has been
confirmed owing to chemical similarities, others exist whose chemical
composition has never been investigated. <BR /> Aims: <ASTROBJ>NGC
5053</ASTROBJ> and <ASTROBJ>NGC 5634</ASTROBJ> are two of these scarcely
studied Sgr dSph candidate-member clusters. To characterize their
composition we analyzed one giant star in <ASTROBJ>NGC 5053</ASTROBJ>,
and two in <ASTROBJ>NGC 5634</ASTROBJ>. <BR /> Methods: We analyze
high-resolution and signal-to-noise spectra by means of the MyGIsFOS
code, determining atmospheric parameters and abundances for up
to 21 species between O and Eu. The abundances are compared with
those of MW halo field stars, of unassociated MW halo globulars,
and of the metal-poor Sgr dSph main body population. <BR /> Results:
We derive a metallicity of [Fe ii/H] = -2.26 ± 0.10 for <ASTROBJ>NGC
5053</ASTROBJ>, and of [Fe i/H] = -1.99 ± 0.075 and -1.97 ± 0.076 for
the two stars in <ASTROBJ>NGC 5634</ASTROBJ>. This makes <ASTROBJ>NGC
5053</ASTROBJ> one of the most metal-poor globular clusters in the
MW. Both clusters display an α enhancement similar to the one of
the halo at comparable metallicity. The two stars in <ASTROBJ>NGC
5634</ASTROBJ> clearly display the Na-O anticorrelation widespread among
MW globulars. Most other abundances are in good agreement with standard
MW halo trends. <BR /> Conclusions: The chemistry of the Sgr dSph main
body populations is similar to that of the halo at low metallicity. It
is thus difficult to discriminate between an origin of <ASTROBJ>NGC
5053</ASTROBJ> and <ASTROBJ>NGC 5634</ASTROBJ> in the Sgr dSph, and
one in the MW. However, the abundances of these clusters do appear
closer to that of Sgr dSph than of the halo, favoring an origin in the
Sgr dSph system. <P />Appendix A is available in electronic form at <A
href="http://www.aanda.org/10.1051/0004-6361/201425509/olm">http://www.aanda.org</A>Atomic
data are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/vol/A104">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/vol/A104</A>
---------------------------------------------------------
Title: Chemical abundances of giant stars in the Crater stellar system
Authors: Bonifacio, P.; Caffau, E.; Zaggia, S.; François, P.;
Sbordone, L.; Andrievsky, S. M.; Korotin, S. A.
2015A&A...579L...6B Altcode: 2015arXiv150603615B
<BR /> Aims: We obtained spectra for two giants of Crater (Crater
J113613-105227 and Crater J113615-105244) using X-Shooter at the
VLT, with the purpose of determining their radial velocities and
metallicities. <BR /> Methods: Radial velocities were determined
by cross-correlating the spectra with that of a standard star. The
spectra were analysed with the MyGIsFOS code using a grid of synthetic
spectra computed from one-dimensional, local thermodynamic equilibrium
(LTE) model atmospheres. Effective temperature and surface gravity
were derived from photometry measured from images obtained by the
Dark Energy Survey. <BR /> Results: The radial velocities are 144.3
± 4.0 km s<SUP>-1</SUP> for Crater J113613-105227 and and 134.1 ±
4.0km s<SUP>-1</SUP> for Crater J113615-105244. The metallicities
are [Fe/H] = -1.73 and [Fe/H] = -1.67, respectively. In addition to
the iron abundance, we were able to determine abundances for nine
elements: Na, Mg, Ca, Ti, V, Cr, Mn, Ni, and Ba. For Na and Ba we
took into account deviations from LTE because the corrections are
significant. The abundance ratios are similar in the two stars and
resemble those of Galactic stars of the same metallicity. In the deep
photometric images we detected several stars that lie to the blue of
the turn-off. <BR /> Conclusions: The radial velocities imply that
both stars are members of the Crater stellar system. The difference
in velocity between the two taken at face value implies a velocity
dispersion >3.7 km s<SUP>-1</SUP> at a 95% confidence level. Our
spectroscopic metallicities agree excellently well with those determined
by previous investigations using photometry. Our deep photometry
and the spectroscopic metallicity imply an age of 7 Gyr for the main
population of the system. The stars to the blue of the turn-off can be
interpreted as a younger population that is of the same metallicity
and an age of 2.2 Gyr. Finally, spatial and kinematical parameters
support the idea that this system is associated with the galaxies
Leo IV and Leo V. All the observations favour the interpretation of
Crater as a dwarf galaxy. <P />Based on observations taken at ESO
Paranal with the Kueyen telescope, programme 094.D-0547.Tables 3-4,
Figs. 4-5, and Appendices are available in electronic form at <A
href="http://www.aanda.org/10.1051/0004-6361/201526366/olm">http://www.aanda.org</A>
---------------------------------------------------------
Title: VizieR Online Data Catalog: Abundances of 3 CEMP stars
(Bonifacio+, 2015)
Authors: Bonifacio, P.; Caffau, E.; Spite, M.; Limongi, M.; Chieffi,
A.; Klessen, R. S.; Francois, P.; Molaro, P.; Ludwig, H. -G.; Zaggia,
S.; Spite, F.; Plez, B.; Cayrel, R.; Christlieb, N.; Clark, P. C.;
Glover, S. C. O.; Hammer, F.; Koch, A.; Monaco, L.; Sbordone, L.;
Steffen, M.
2015yCat..35790028B Altcode:
We analyse both X-Shooter and UVES spectra acquired at the VLT. We used
a traditional abundance analysis based on OSMARCS 1D Local Thermodynamic
Equilibrium (LTE) model atmospheres and the TURBOSPECTRUM line formation
code. <P />(2 data files).
---------------------------------------------------------
Title: Galactic evolution of sulphur as traced by globular clusters
Authors: Kacharov, N.; Koch, A.; Caffau, E.; Sbordone, L.
2015A&A...577A..18K Altcode: 2015arXiv150302691K
Context. Sulphur is an important volatile α element, but its role
in the Galactic chemical evolution is still uncertain, and more
observations constraining the sulphur abundance in stellar photospheres
are required. <BR /> Aims: We derive the sulphur abundances in red
giant branch (RGB) stars in three Galactic halo globular clusters
(GC) that cover a wide metallicity range (-2.3 < [Fe/H] < -1.2):
M 4 (NGC 6121), M 22 (NGC 6656), and M 30 (NGC 7099). The halo field
stars show a large scatter in the [S/Fe] ratio in this metallicity
span, which is inconsistent with canonical chemical evolution
models. To date, very few measurements of [S/Fe] exist for stars
in GCs, which are good tracers of the chemical enrichment of their
environment. However, some light and α elements show star-to-star
variations within individual GCs, and it is as yet unclear whether
the α element sulphur also varies between GC stars. <BR /> Methods:
We used the infrared spectrograph CRIRES to obtain high-resolution (R ~
50 000), high signal-to-noise (S/N ~ 200 per px) spectra in the region
of the S I multiplet 3 at 1045 nm for 15 GC stars selected from the
literature (six stars in M 4,six stars in M 22, and three stars in M
30). Multiplet 3 is better suited for S abundance derivation than the
more commonly used lines of multiplet 1 at 920 nm, since its lines are
not blended by telluric absorption or other stellar features at low
metallicity. <BR /> Results: We used spectral synthesis to derive the
[S/Fe] ratio of the stars assuming local thermodynamic equilibrium
(LTE). We find mean [S/Fe]<SUB>LTE</SUB> = 0.58 ± 0.01 ± 0.20 dex
(statistical and systematic error) for M 4, [S/Fe]<SUB>LTE</SUB> =
0.57 ± 0.01 ± 0.19 dex for M 22, and [S/Fe]<SUB>LTE</SUB> = 0.55 ±
0.02 ± 0.16 dex for M 30. The negative NLTE corrections are estimated
to be in the order of the systematic uncertainties. We do not detect
star-to-star variations of the S abundance in any of the observed
GCs, with the possible exception of two individual stars, one in M
22 and one in M 30, which appear to be highly enriched in S. <BR />
Conclusions: With the tentative exception of two stars with measured
high S abundances, we conclude that sulphur behaves like a typical
α element in the studied Galactic GCs, showing enhanced abundances
with respect to the solar value at metallicities below [Fe/H]-1.0
dex without a considerable spread. <P />Based on observations
made with ESO telescopes at the La Silla Paranal Observatory under
programmes ID 091.B-0171(A).The reduced spectra and the best fit
synthetic models are available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/577/A18">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/577/A18</A>
---------------------------------------------------------
Title: VizieR Online Data Catalog: Abundances in NGC 5053 and NGC 5634
(Sbordone+, 2015)
Authors: Sbordone, L.; Monaco, L.; Moni Bidin, C.; Bonifacio, P.;
Villanova, S.; Bellazzini, M.; Ibata, R.; Chiba, M.; Geisler, D.;
Caffau, E.; Duffau, S.
2015yCat..35790104S Altcode:
These two tables contain the results relative to the fitting of all
the individual spectral features employed in the analysis. The
"alllines.dat" table contains the feature characteristics
(e.g. ion abundance fitted through the feature, starting and ending
wavelength...), the fitting results (e.g. the derived abundance)
and a star and feature identifiers. The second table (allsynth.txt)
contain the detailed observed and fitted profiles for each feature. Each
line contains the star and feature identifiers, the wavelength of that
specific "pixel" and the corresponding observed and fitted normalized
fluxes. <P />(3 data files).
---------------------------------------------------------
Title: Three-dimensional hydrodynamical CO<SUP>5</SUP>BOLD model
atmospheres of red giant stars. IV. Oxygen diagnostics in extremely
metal-poor red giants with infrared OH lines
Authors: Dobrovolskas, V.; Kučinskas, A.; Bonifacio, P.; Caffau,
E.; Ludwig, H. -G.; Steffen, M.; Spite, M.
2015A&A...576A.128D Altcode: 2015arXiv150206587D
Context. Although oxygen is an important tracer of Galactic chemical
evolution, measurements of its abundance in the atmospheres of the
oldest Galactic stars are still scarce and rather imprecise. This
is mainly because only a few spectral lines are available for the
abundance diagnostics. At the lowest end of the metallicity scale,
oxygen can only be measured in giant stars and in most of cases such
measurements rely on a single forbidden [O i] 630 nm line that is very
weak and frequently blended with telluric lines. Although molecular
OH lines located in the ultraviolet and infrared could also be used
for the diagnostics, oxygen abundances obtained from the OH lines and
the [O i] 630 nm line are usually discrepant to a level of ~ 0.3-0.4
dex. <BR /> Aims: We study the influence of convection on the formation
of the infrared (IR) OH lines and the forbidden [O i] 630 nm line in the
atmospheres of extremely metal-poor (EMP) red giant stars. Our ultimate
goal is to clarify whether a realistic treatment of convection with
state-of-the-art 3D hydrodynamical model atmospheres may help to bring
the oxygen abundances obtained using the two indicators into closer
agreement. <BR /> Methods: We used high-resolution (R = 50 000) and high
signal-to-noise ratio (S/N ≈ 200-600) spectra of four EMP red giant
stars obtained with the VLT CRIRES spectrograph. For each EMP star,
4-14 IR OH vibrational-rotational lines located in the spectral range of
1514-1548 and 1595-1632 nm were used to determine oxygen abundances by
employing standard 1D local thermodynamic equilibrium (LTE) abundance
analysis methodology. We then corrected the 1D LTE abundances
obtained from each individual OH line for the 3D hydrodynamical
effects, which was done by applying 3D-1D LTE abundance corrections
that were determined using 3D hydrodynamical CO<SUP>5</SUP>BOLD and
1D hydrostatic LHD model atmospheres. <BR /> Results: We find that
the influence of convection on the formation of [O i] 630 nm line in
the atmospheres of EMP giants studied here is minor, which leads to
very small 3D-1D abundance corrections (Δ<SUB>3D-1D</SUB> ≤ -0.01
dex). On the contrary, IR OH lines are strongly affected by convection
and thus the abundance corrections for these lines are significant,
Δ<SUB>3D-1D</SUB> ≈ -0.2···-0.3 dex. These abundance corrections
do indeed bring the 1D LTE oxygen abundances of EMP red giants obtained
using IR OH lines into better agreement with those determined from the
[O i] 630 nm line. Since in the EMP red giants IR OH lines are typically
at least a factor of two stronger than the [O i] line, OH lines may be
useful indicators of oxygen abundances in the EMP stars, provided that
the analysis is based on 3D hydrodynamical model atmospheres. <P />Based
on observations obtained at the European Southern Observatory (ESO)
Very Large Telescope (VLT) at Paranal Observatory, Chile (observing
programme 089.D-0079).Appendices are available in electronic form at <A
href="http://www.aanda.org/10.1051/0004-6361/201424885/olm">http://www.aanda.org</A>
---------------------------------------------------------
Title: VizieR Online Data Catalog: Reduced CRIRES spectra around S
multiplet 3 (Kacharov+, 2015)
Authors: Kacharov, N.; Koch, A.; Caffau, E.; Sbordone, L.
2015yCat..35770018K Altcode: 2015yCat..35779018K
We provide the reduced CRIRES spectra in the region of the S multiplet
3 for all 15 analysed stars together with the best fit synthetic
spectra. We have interpolated the Kurucz AODFNEW alpha-enhanced models
to produce the synthetic spectra with scaled solar input abundances
except the alpha elements, where [alpha/Fe]=0.4dex. The parameters
for the synthesis are provided in Table 1 of the article. <P />(2
data files).
---------------------------------------------------------
Title: Oxygen in the Early Galaxy: OH Lines as Tracers of Oxygen
Abundance in Extremely Metal-Poor Giant Stars
Authors: Kucinskas, A.; Dobrovolskas, V.; Bonifacio, P.; Caffau, E.;
Ludwig, H. -G.; Steffen, M.; Spite, M.
2015csss...18..327K Altcode: 2014arXiv1409.3153K
Oxygen is a powerful tracer element of Galactic chemical
evolution. Unfortunately, only a few oxygen lines are available in the
ultraviolet-infrared stellar spectra for the reliable determination of
its abundance. Moreover, oxygen abundances obtained using different
spectral lines often disagree significantly. In this contribution we
therefore investigate whether the inadequate treatment of convection in
1D hydrostatic model atmospheres used in the abundance determinations
may be responsible for this disagreement. For this purpose, we used VLT
CRIRES spectra of three EMP giants, as well as 3D hydrodynamical COBOLD
and 1D hydrostatic LHD model atmospheres, to investigate the role of
convection in the formation of infrared (IR) OH lines. Our results show
that the presence of convection leads to significantly stronger IR OH
lines. As a result, the difference in the oxygen abundance determined
from IR OH lines with 3D hydrodynamical and classical 1D hydrostatic
model atmospheres may reach -0.2 dots -0.3 dex. In case of the three
EMP giants studied here, we obtain a good agrement between the 3D LTE
oxygen abundances determined by us using vibrational-rotational IR
OH lines in the spectral range of 1514-1626 nm, and oxygen abundances
determined from forbidden [O I] 630 nm line in previous studies.
---------------------------------------------------------
Title: The Gaia-ESO Survey: Extracting diffuse interstellar bands
from cool star spectra. DIB-based interstellar medium line-of-sight
structures at the kpc scale
Authors: Puspitarini, L.; Lallement, R.; Babusiaux, C.; Chen, H. -C.;
Bonifacio, P.; Sbordone, L.; Caffau, E.; Duffau, S.; Hill, V.;
Monreal-Ibero, A.; Royer, F.; Arenou, F.; Peralta, R.; Drew, J. E.;
Bonito, R.; Lopez-Santiago, J.; Alfaro, E. J.; Bensby, T.; Bragaglia,
A.; Flaccomio, E.; Lanzafame, A. C.; Pancino, E.; Recio-Blanco, A.;
Smiljanic, R.; Costado, M. T.; Lardo, C.; de Laverny, P.; Zwitter, T.
2015A&A...573A..35P Altcode: 2014arXiv1410.0842P
<BR /> Aims: We study how diffuse interstellar bands (DIBs) measured
toward distance-distributed target stars can be used to locate dense
interstellar (IS) clouds in the Galaxy and probe a line-of-sight (LOS)
kinematical structure, a potentially useful tool when gaseous absorption
lines are saturated or not available in the spectral range. Cool target
stars are numerous enough for this purpose. <BR /> Methods: We devised
automated DIB-fitting methods appropriate for cool star spectra and
multiple IS components. The data were fitted with a combination of
a synthetic stellar spectrum, a synthetic telluric transmission,
and empirical DIB profiles. The initial number of DIB components and
their radial velocity were guided by HI 21 cm emission spectra, or, when
available in the spectral range, IS neutral sodium absorption lines. For
NaI, radial velocities of NaI lines and DIBs were maintained linked
during a global simultaneous fit. In parallel, stellar distances and
extinctions were estimated self-consistently by means of a 2D Bayesian
method from spectroscopically-derived stellar parameters and photometric
data. <BR /> Results: We have analyzed Gaia-ESO Survey (GES) spectra of
225 stars that probe between ~2 and 10 kpc long LOS in five different
regions of the Milky Way. The targets are the two CoRoT fields, two
open clusters (NGC 4815 and γ Vel), and the Galactic bulge. Two OGLE
fields toward the bulge observed before the GES are also included
(205 target stars). Depending on the observed spectral intervals, we
extracted one or more of the following DIBs: λλ 6283.8, 6613.6, and
8620.4. For each field, we compared the DIB strengths with the Bayesian
distances and extinctions, and the DIB Doppler velocities with the HI
emission spectra. <BR /> Conclusions: For all fields, the DIB strength
and the target extinction are well correlated. For targets that are
widely distributed in distance, marked steps in DIBs and extinction
radial distance profiles match each other and broadly correspond to the
expected locations of spiral arms. For all fields, the DIB velocity
structure agrees with HI emission spectra, and all detected DIBs
correspond to strong NaI lines. This illustrates how DIBs can be used
to locate the Galactic interstellar gas and to study its kinematics at
the kpc scale, as illustrated by Local and Perseus Arm DIBs that differ
by ≳30 km s<SUP>-1</SUP>, in agreement with HI emission spectra. On
the other hand, if most targets are located beyond the main absorber,
DIBs can trace the differential reddening within the field. <P />Based
on observations made with the ESO/VLT at Paranal Observatory, under
programs 188.B-3002 (The Gaia-ESO Public Spectroscopic Survey) and
079.B-0662.Tables with the basic data and observed parameters for
the 429 stars are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/573/A35">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/573/A35</A>
---------------------------------------------------------
Title: The Science Case for Multi-Object Spectroscopy on the
European ELT
Authors: Evans, Chris; Puech, Mathieu; Afonso, Jose; Almaini, Omar;
Amram, Philippe; Aussel, Hervé; Barbuy, Beatriz; Basden, Alistair;
Bastian, Nate; Battaglia, Giuseppina; Biller, Beth; Bonifacio,
Piercarlo; Bouché, Nicholas; Bunker, Andy; Caffau, Elisabetta;
Charlot, Stephane; Cirasuolo, Michele; Clenet, Yann; Combes, Francoise;
Conselice, Chris; Contini, Thierry; Cuby, Jean-Gabriel; Dalton,
Gavin; Davies, Ben; de Koter, Alex; Disseau, Karen; Dunlop, Jim;
Epinat, Benoît; Fiore, Fabrizio; Feltzing, Sofia; Ferguson, Annette;
Flores, Hector; Fontana, Adriano; Fusco, Thierry; Gadotti, Dimitri;
Gallazzi, Anna; Gallego, Jesus; Giallongo, Emanuele; Gonçalves,
Thiago; Gratadour, Damien; Guenther, Eike; Hammer, Francois; Hill,
Vanessa; Huertas-Company, Marc; Ibata, Roridgo; Kaper, Lex; Korn,
Andreas; Larsen, Søren; Le Fèvre, Olivier; Lemasle, Bertrand;
Maraston, Claudia; Mei, Simona; Mellier, Yannick; Morris, Simon;
Östlin, Göran; Paumard, Thibaut; Pello, Roser; Pentericci,
Laura; Peroux, Celine; Petitjean, Patrick; Rodrigues, Myriam;
Rodríguez-Muñoz, Lucía; Rouan, Daniel; Sana, Hugues; Schaerer,
Daniel; Telles, Eduardo; Trager, Scott; Tresse, Laurence; Welikala,
Niraj; Zibetti, Stefano; Ziegler, Bodo
2015arXiv150104726E Altcode:
This White Paper presents the scientific motivations for a
multi-object spectrograph (MOS) on the European Extremely Large
Telescope (E-ELT). The MOS case draws on all fields of contemporary
astronomy, from extra-solar planets, to the study of the halo of the
Milky Way and its satellites, and from resolved stellar populations
in nearby galaxies out to observations of the earliest 'first-light'
structures in the partially-reionised Universe. The material presented
here results from thorough discussions within the community over the
past four years, building on the past competitive studies to agree a
common strategy toward realising a MOS capability on the E-ELT. The
cases have been distilled to a set of common requirements which will
be used to define the MOSAIC instrument, entailing two observational
modes ('high multiplex' and 'high definition'). When combined with
the unprecedented sensitivity of the E-ELT, MOSAIC will be the world's
leading MOS facility. In analysing the requirements we also identify a
high-multiplex MOS for the longer-term plans for the E-ELT, with an even
greater multiplex (>1000 targets) to enable studies of large-scale
structures in the high-redshift Universe. Following the green light
for the construction of the E-ELT the MOS community, structured through
the MOSAIC consortium, is eager to realise a MOS on the E-ELT as soon
as possible. We argue that several of the most compelling cases for ELT
science, in highly competitive areas of modern astronomy, demand such a
capability. For example, MOS observations in the early stages of E-ELT
operations will be essential for follow-up of sources identified by the
James Webb Space Telescope (JWST). In particular, multi-object adaptive
optics and accurate sky subtraction with fibres have both recently been
demonstrated on sky, making fast-track development of MOSAIC feasible.
---------------------------------------------------------
Title: The low Sr/Ba ratio on some extremely metal-poor stars
Authors: Spite, M.; Spite, F.; Bonifacio, P.; Caffau, E.; François,
P.; Sbordone, L.
2014A&A...571A..40S Altcode: 2014arXiv1410.0847S
Context. It has been noted that, in classical extremely metal-poor
(EMP) stars, the abundance ratio of two well-observed neutron-capture
elements, Sr and Ba, is always higher than [Sr/Ba] = -0.5, which is the
value of the solar r-only process; however, a handful of EMP stars have
recently been found with a very low Sr/Ba ratio. <BR /> Aims: We try to
understand the origin of this anomaly by comparing the abundance pattern
of the elements in these stars and in the classical EMP stars. <BR />
Methods: For a rigorous comparison with previous data, four stars with
very low Sr/Ba ratios were observed and analyzed in the same way as in
the First Stars program: analysis within LTE approximation through 1D
(hydrostatic) model atmosphere, providing homogeneous abundances of
nine neutron-capture elements. <BR /> Results: In CS 22950-173, the
only turnoff star of the sample, the Sr/Ba ratio is, in fact, found to
be higher than the r-only solar ratio, so the star is discarded. The
remaining stars (CS 29493-090, CS 30322-023, HE 305-4520) are cool
evolved giants. They do not present a clear carbon enrichment, but in
evolved giants C is partly burned into N, and owing to their high N
abundance, they could still have initially been carbon-rich EMP stars
(CEMP). The abundances of Na to Mg present similar anomalies to those
in CEMP stars. The abundance patterns of the neutron-capture elements
in the three stars are strikingly similar to a theoretical s-process
pattern. This pattern could at first be attributed to pollution by a
nearby AGB, but none of the stars presents a clear variation in the
radial velocity indicating the presence of a companion. The stellar
parameters seem to exclude any internal pollution in a TP-AGB phase
for at least two of these stars. The possibility that the stars
are early-AGB stars polluted during the core He flash does not seem
compatible with the theory. <P />Based on observations obtained with the
ESO Very Large Telescope at Paranal Observatory, Chile (ID 077.D-0299(A)
PI Bonifacio, and ID 078.B-0238(A) PI Spite), and on archive data
ID 076.D-0451(A) PI Johnson.The line list and the abundances line
by line are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/571/A40">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/571/A40</A>
---------------------------------------------------------
Title: Chemical abundances of the metal-poor horizontal-branch stars
<ASTROBJ>CS 22186-005</ASTROBJ> and <ASTROBJ>CS 30344-033</ASTROBJ>
Authors: Çalışkan, Ş.; Caffau, E.; Bonifacio, P.; Christlieb,
N.; Monaco, L.; Beers, T. C.; Albayrak, B.; Sbordone, L.
2014A&A...571A..62C Altcode: 2014arXiv1410.2189C
We report on a chemical-abundance analysis of two very metal-poor
horizontal-branch stars in the Milky Way halo: CS 22186-005 ([ Fe/H ]
= -2.70) and CS 30344-033 ([ Fe/H ] = -2.90). The analysis is based
on high-resolution spectra obtained at ESO, with the spectrographs
HARPS at the 3.6 m telescope, and UVES at the VLT. We adopted
one-dimensional, plane-parallel model atmospheres assuming local
thermodynamic equilibrium. We derived elemental abundances for 13
elements for CS 22186-005 and 14 elements for CS 30344-033. This
study is the first abundance analysis of CS 30344-033. CS 22186-005
has been analyzed previously, but we report here the first measurement
of nickel (Ni; Z = 28) for this star, based on twenty-two Ni i lines
([ Ni/Fe ] = -0.21 ± 0.02); the measurement is significantly below
the mean found for most metal-poor stars. Differences of up to 0.5
dex in [ Ni/Fe ] ratios were determined by different authors for the
same type of stars in the literature, which means that it is not yet
possible to conclude that there is a real intrinsic scatter in the [
Ni/Fe ] ratios. For the other elements for which we obtained estimates,
the abundance patterns in these two stars match the Galactic trends
defined by giant and turnoff stars well. This confirms the value of
horizontal-branch stars as tracers of the chemical properties of stellar
populations in the Galaxy. Our radial velocities measurements for CS
22186-005 differ from previously published measurements by more than the
expected statistical errors. More measurements of the radial velocity
of this star are encouraged to confirm or refute its radial velocity
variability. <P />Based on observations collected at the European
Southern Observatory, Chile, Program IDs 077.D-0299 and 076.D-0546(A).
---------------------------------------------------------
Title: VizieR Online Data Catalog: Abundances in 2 extremely
metal-poor stars (Spite+, 2014)
Authors: Spite, M.; Spite, F.; Bonifacio, P.; Caffau, E.; Francois,
P.; Sbordone, L.
2014yCat..35710040S Altcode: 2014yCat..35719040S
For the two low-Sr/Ba stars CS29493-090 and HE305-4520 we give, line
by line, the main line parameters and the logarithm of the abundances
for logA(H)=12. <P />(1 data file).
---------------------------------------------------------
Title: The Gaia-ESO Survey: The analysis of high-resolution UVES
spectra of FGK-type stars
Authors: Smiljanic, R.; Korn, A. J.; Bergemann, M.; Frasca, A.;
Magrini, L.; Masseron, T.; Pancino, E.; Ruchti, G.; San Roman,
I.; Sbordone, L.; Sousa, S. G.; Tabernero, H.; Tautvaišienė,
G.; Valentini, M.; Weber, M.; Worley, C. C.; Adibekyan, V. Zh.;
Allende Prieto, C.; Barisevičius, G.; Biazzo, K.; Blanco-Cuaresma,
S.; Bonifacio, P.; Bragaglia, A.; Caffau, E.; Cantat-Gaudin, T.;
Chorniy, Y.; de Laverny, P.; Delgado-Mena, E.; Donati, P.; Duffau,
S.; Franciosini, E.; Friel, E.; Geisler, D.; González Hernández,
J. I.; Gruyters, P.; Guiglion, G.; Hansen, C. J.; Heiter, U.; Hill, V.;
Jacobson, H. R.; Jofre, P.; Jönsson, H.; Lanzafame, A. C.; Lardo, C.;
Ludwig, H. -G.; Maiorca, E.; Mikolaitis, Š.; Montes, D.; Morel, T.;
Mucciarelli, A.; Muñoz, C.; Nordlander, T.; Pasquini, L.; Puzeras,
E.; Recio-Blanco, A.; Ryde, N.; Sacco, G.; Santos, N. C.; Serenelli,
A. M.; Sordo, R.; Soubiran, C.; Spina, L.; Steffen, M.; Vallenari,
A.; Van Eck, S.; Villanova, S.; Gilmore, G.; Randich, S.; Asplund,
M.; Binney, J.; Drew, J.; Feltzing, S.; Ferguson, A.; Jeffries, R.;
Micela, G.; Negueruela, I.; Prusti, T.; Rix, H. -W.; Alfaro, E.;
Babusiaux, C.; Bensby, T.; Blomme, R.; Flaccomio, E.; François, P.;
Irwin, M.; Koposov, S.; Walton, N.; Bayo, A.; Carraro, G.; Costado,
M. T.; Damiani, F.; Edvardsson, B.; Hourihane, A.; Jackson, R.; Lewis,
J.; Lind, K.; Marconi, G.; Martayan, C.; Monaco, L.; Morbidelli, L.;
Prisinzano, L.; Zaggia, S.
2014A&A...570A.122S Altcode: 2014arXiv1409.0568S
Context. The ongoing Gaia-ESO Public Spectroscopic Survey is using
FLAMES at the VLT to obtain high-quality medium-resolution Giraffe
spectra for about 10<SUP>5</SUP> stars and high-resolution UVES spectra
for about 5000 stars. With UVES, the Survey has already observed
1447 FGK-type stars. <BR /> Aims: These UVES spectra are analyzed
in parallel by several state-of-the-art methodologies. Our aim is
to present how these analyses were implemented, to discuss their
results, and to describe how a final recommended parameter scale is
defined. We also discuss the precision (method-to-method dispersion)
and accuracy (biases with respect to the reference values) of the
final parameters. These results are part of the Gaia-ESO second
internal release and will be part of its first public release of
advanced data products. <BR /> Methods: The final parameter scale is
tied to the scale defined by the Gaia benchmark stars, a set of stars
with fundamental atmospheric parameters. In addition, a set of open
and globular clusters is used to evaluate the physical soundness
of the results. Each of the implemented methodologies is judged
against the benchmark stars to define weights in three different
regions of the parameter space. The final recommended results are
the weighted medians of those from the individual methods. <BR />
Results: The recommended results successfully reproduce the atmospheric
parameters of the benchmark stars and the expected T<SUB>eff</SUB>-log
g relation of the calibrating clusters. Atmospheric parameters and
abundances have been determined for 1301 FGK-type stars observed with
UVES. The median of the method-to-method dispersion of the atmospheric
parameters is 55 K for T<SUB>eff</SUB>, 0.13 dex for log g and 0.07
dex for [Fe/H]. Systematic biases are estimated to be between 50-100
K for T<SUB>eff</SUB>, 0.10-0.25 dex for log g and 0.05-0.10 dex for
[Fe/H]. Abundances for 24 elements were derived: C, N, O, Na, Mg, Al,
Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ba, Nd, and
Eu. The typical method-to-method dispersion of the abundances varies
between 0.10 and 0.20 dex. <BR /> Conclusions: The Gaia-ESO sample of
high-resolution spectra of FGK-type stars will be among the largest of
its kind analyzed in a homogeneous way. The extensive list of elemental
abundances derived in these stars will enable significant advances in
the areas of stellar evolution and Milky Way formation and evolution. <P
/>Based on observations made with the ESO/VLT, at Paranal Observatory,
under program 188.B-3002 (The Gaia-ESO Public Spectroscopic Survey, PIs
Gilmore and Randich). Appendices are available in electronic form at <A
href="http://www.aanda.org/10.1051/0004-6361/201423937/olm">http://www.aanda.org</A>
---------------------------------------------------------
Title: Clues on the Galactic evolution of sulphur from star clusters
Authors: Caffau, E.; Monaco, L.; Spite, M.; Bonifacio, P.; Carraro,
G.; Ludwig, H. -G.; Villanova, S.; Beletsky, Y.; Sbordone, L.
2014A&A...568A..29C Altcode: 2014arXiv1407.0485C
Context. The abundances of α-elements are a powerful diagnostic of the
star formation history and chemical evolution of a galaxy. Sulphur,
being moderately volatile, can be reliably measured in the
interstellar medium (ISM) of damped Ly-α galaxies and extragalactic
H ii regions. Measurements in stars of different metallicity in our
Galaxy can then be readily compared to the abundances in external
galaxies. Such a comparison is not possible for Si or Ca that suffer
depletion onto dust in the ISM. Furthermore, studying sulphur is
interesting because it probes nucleosynthetic conditions that are
very different from those of O or Mg. In this context measurements
in star clusters are a reliable tracers of the Galactic evolution of
sulphur. <BR /> Aims: The aim of this paper is to determine sulphur
abundances in several Galactic clusters that span a metallicity range
-1.5 < [Fe/H] < 0.0. <BR /> Methods: We use a standard abundance
analysis, based on 1D model atmospheres in local thermodynamical
equilibrium (LTE) and literature corrections for non-LTE (NLTE), as
well as 3D corrections based on hydrodynamical model atmospheres, to
derive sulphur abundances in a sample of stars in the globular cluster
M 4, and the open clusters Trumpler 5, NGC 2477, and NGC 5822. <BR />
Results: We find ⟨ A(S) ⟩ <SUB>NLTE</SUB> = 6.11 ± 0.04 for M 4,
⟨ A(S) ⟩ <SUB>NLTE</SUB> = 7.17 ± 0.02 for NGC 2477, and ⟨ A(S)
⟩ <SUB>NLTE</SUB> = 7.13 ± 0.06 for NGC 5822. For the only star
studied in Trumpler 5 we find A(S)<SUB>NLTE</SUB> = 6.43 ± 0.03 and
A(S)<SUB>LTE</SUB> = 6.94 ± 0.05. <BR /> Conclusions: Our measurements
show that, by and large, the S abundances in Galactic clusters trace
reliably those in field stars. The only possible exception is Trumpler
5, for which the NLTE sulphur abundance implies an [S/Fe] ratio lower by
roughly 0.4 dex than observed in field stars of comparable metallicity,
even though its LTE sulphur abundance is in line with abundances of
field stars. Moreover the LTE sulphur abundance is consistent only
with the abundance of another α-element, Mg, in the same star,
while the low NLTE value is consistent with Si and Ca. We believe
that further investigation of departures from LTE is necessary,
as well as observation of other S i lines in this star and in other
stars of the same cluster, before one can conclude that the sulphur
abundance in Trumpler 5 is indeed 0.4 dex lower than in field stars
of comparable metallicity. The S abundances in our sample of stars
in clusters imply that the clusters are chemically homogeneous for S
within 0.05 dex. <P />Based on observations made with ESO Telescopes
at the La Silla Paranal Observatory under programme ID 085.D-0537(A),
088.D-0045(A), 089.D-0062(B).
---------------------------------------------------------
Title: 4MOST: 4-metre Multi-Object Spectroscopic Telescope
Authors: de Jong, Roelof S.; Barden, Sam; Bellido-Tirado, Olga;
Brynnel, Joar; Chiappini, Cristina; Depagne, Éric; Haynes, Roger;
Johl, Diana; Phillips, Daniel P.; Schnurr, Olivier; Schwope, Axel D.;
Walcher, Jakob; Bauer, Svend M.; Cescutti, Gabriele; Cioni, Maria-Rosa
L.; Dionies, Frank; Enke, Harry; Haynes, Dionne M.; Kelz, Andreas;
Kitaura, Francisco S.; Lamer, Georg; Minchev, Ivan; Müller, Volker;
Nuza, Sebastián. E.; Olaya, Jean-Christophe; Piffl, Tilmann; Popow,
Emil; Saviauk, Allar; Steinmetz, Matthias; Ural, Uǧur; Valentini,
Monica; Winkler, Roland; Wisotzki, Lutz; Ansorge, Wolfgang R.; Banerji,
Manda; Gonzalez Solares, Eduardo; Irwin, Mike; Kennicutt, Robert C.;
King, David M. P.; McMahon, Richard; Koposov, Sergey; Parry, Ian R.;
Sun, Xiaowei; Walton, Nicholas A.; Finger, Gert; Iwert, Olaf; Krumpe,
Mirko; Lizon, Jean-Louis; Mainieri, Vincenzo; Amans, Jean-Philippe;
Bonifacio, Piercarlo; Cohen, Matthieu; François, Patrick; Jagourel,
Pascal; Mignot, Shan B.; Royer, Frédéric; Sartoretti, Paola; Bender,
Ralf; Hess, Hans-Joachim; Lang-Bardl, Florian; Muschielok, Bernard;
Schlichter, Jörg; Böhringer, Hans; Boller, Thomas; Bongiorno,
Angela; Brusa, Marcella; Dwelly, Tom; Merloni, Andrea; Nandra, Kirpal;
Salvato, Mara; Pragt, Johannes H.; Navarro, Ramón; Gerlofsma, Gerrit;
Roelfsema, Ronald; Dalton, Gavin B.; Middleton, Kevin F.; Tosh,
Ian A.; Boeche, Corrado; Caffau, Elisabetta; Christlieb, Norbert;
Grebel, Eva K.; Hansen, Camilla J.; Koch, Andreas; Ludwig, Hans-G.;
Mandel, Holger; Quirrenbach, Andreas; Sbordone, Luca; Seifert, Walter;
Thimm, Guido; Helmi, Amina; trager, Scott C.; Bensby, Thomas; Feltzing,
Sofia; Ruchti, Gregory; Edvardsson, Bengt; Korn, Andreas; Lind, Karin;
Boland, Wilfried; Colless, Matthew; Frost, Gabriella; Gilbert, James;
Gillingham, Peter; Lawrence, Jon; Legg, Neville; Saunders, Will;
Sheinis, Andrew; Driver, Simon; Robotham, Aaron; Bacon, Roland;
Caillier, Patrick; Kosmalski, Johan; Laurent, Florence; Richard, Johan
2014SPIE.9147E..0MD Altcode:
4MOST is a wide-field, high-multiplex spectroscopic survey facility
under development for the VISTA telescope of the European Southern
Observatory (ESO). Its main science drivers are in the fields
of galactic archeology, high-energy physics, galaxy evolution
and cosmology. 4MOST will in particular provide the spectroscopic
complements to the large area surveys coming from space missions like
Gaia, eROSITA, Euclid, and PLATO and from ground-based facilities like
VISTA, VST, DES, LSST and SKA. The 4MOST baseline concept features a 2.5
degree diameter field-of-view with ~2400 fibres in the focal surface
that are configured by a fibre positioner based on the tilting spine
principle. The fibres feed two types of spectrographs; ~1600 fibres go
to two spectrographs with resolution R<5000 (λ~390-930 nm) and ~800
fibres to a spectrograph with R>18,000 (λ~392-437 nm and 515-572 nm
and 605-675 nm). Both types of spectrographs are fixed-configuration,
three-channel spectrographs. 4MOST will have an unique operations
concept in which 5 year public surveys from both the consortium and
the ESO community will be combined and observed in parallel during each
exposure, resulting in more than 25 million spectra of targets spread
over a large fraction of the southern sky. The 4MOST Facility Simulator
(4FS) was developed to demonstrate the feasibility of this observing
concept. 4MOST has been accepted for implementation by ESO with
operations expected to start by the end of 2020. This paper provides
a top-level overview of the 4MOST facility, while other papers in
these proceedings provide more detailed descriptions of the instrument
concept[1], the instrument requirements development[2], the systems
engineering implementation[3], the instrument model[4], the fibre
positioner concepts[5], the fibre feed[6], and the spectrographs[7].
---------------------------------------------------------
Title: VizieR Online Data Catalog: Abundances of 47 Tuc turn-off stars
(Dobrovolskas+, 2014)
Authors: Dobrovolskas, V.; Kucinskas, A.; Bonifacio, P.; Korotin,
S. A.; Steffen, M.; Sbordone, L.; Caffau, E.; Ludwig, H. -G.; Royer,
F.; Prakapavicius, D.
2014yCat..35650121D Altcode: 2014yCat..35659121D
Spectra of the TO stars in 47 Tuc investigated in this work were
obtained with the GIRAFFE spectrograph in August-September, 2008,
under the programme 081.D-0287(A) (PI: Shen). The same data set
was independently analysed by D'Orazi et al. (2010ApJ...713L...1D,
Cat. J/ApJ/713/L1). <P />(1 data file).
---------------------------------------------------------
Title: Science case and requirements for the MOSAIC concept for a
multi-object spectrograph for the European Extremely Large Telescope
Authors: Evans, C. J.; Puech, M.; Barbuy, B.; Bonifacio, P.; Cuby,
J. -G.; Guenther, E.; Hammer, F.; Jagourel, P.; Kaper, L.; Morris,
S. L.; Afonso, J.; Amram, P.; Aussel, H.; Basden, A.; Bastian,
N.; Battaglia, G.; Biller, B.; Bouché, N.; Caffau, E.; Charlot,
S.; Clénet, Y.; Combes, F.; Conselice, C.; Contini, T.; Dalton,
G.; Davies, B.; Disseau, K.; Dunlop, J.; Fiore, F.; Flores, H.;
Fusco, T.; Gadotti, D.; Gallazzi, A.; Giallongo, E.; Gonçalves,
T.; Gratadour, D.; Hill, V.; Huertas-Company, M.; Ibata, R.; Larsen,
S.; Le Fèvre, O.; Lemasle, B.; Maraston, C.; Mei, S.; Mellier, Y.;
Östlin, G.; Paumard, T.; Pello, R.; Pentericci, L.; Petitjean, P.;
Roth, M.; Rouan, D.; Schaerer, D.; Telles, E.; Trager, S.; Welikala,
N.; Zibetti, S.; Ziegler, B.
2014SPIE.9147E..96E Altcode: 2014arXiv1406.6369E
Over the past 18 months we have revisited the science requirements
for a multi-object spectrograph (MOS) for the European Extremely Large
Telescope (E-ELT). These efforts span the full range of E-ELT science
and include input from a broad cross-section of astronomers across
the ESO partner countries. In this contribution we summarise the key
cases relating to studies of high-redshift galaxies, galaxy evolution,
and stellar populations, with a more expansive presentation of a
new case relating to detection of exoplanets in stellar clusters. A
general requirement is the need for two observational modes to best
exploit the large (>=40 arcmin<SUP>2</SUP>) patrol field of the
E-ELT. The first mode (`high multiplex') requires integrated-light
(or coarsely resolved) optical/near-IR spectroscopy of >100
objects simultaneously. The second (`high definition'), enabled by
wide-field adaptive optics, requires spatially-resolved, near-IR of
>10 objects/sub-fields. Within the context of the conceptual study
for an ELT-MOS called MOSAIC, we summarise the toplevel requirements
from each case and introduce the next steps in the design process.
---------------------------------------------------------
Title: High-resolution abundance analysis of very metal-poor r-I stars
Authors: Siqueira Mello, C.; Hill, V.; Barbuy, B.; Spite, M.; Spite,
F.; Beers, T. C.; Caffau, E.; Bonifacio, P.; Cayrel, R.; François,
P.; Schatz, H.; Wanajo, S.
2014A&A...565A..93S Altcode: 2014arXiv1404.0234S
Context. Moderately r-process-enriched stars (r-I; +0.3 ≤ [Eu/Fe]
≤ +1.0) are at least four times as common as those that are greatly
enriched in r-process elements (r-II; [Eu/Fe] > +1.0), and the
abundances in their atmospheres are important tools for obtaining a
better understanding of the nucleosynthesis processes responsible
for the origin of the elements beyond the iron peak. <BR /> Aims:
The main aim of this work is to derive abundances for a sample of
seven metal-poor stars with -3.4 ≤ [Fe/H] ≤ -2.4 classified as
r-I stars, to understand the role of these stars for constraining
the astrophysical nucleosynthesis event(s) that is (are) responsible
for the production of the r-process, and to investigate whether they
differ, in any significant way, from the r-II stars. <BR /> Methods:
We carried out a detailed abundance analysis based on high-resolution
spectra obtained with the VLT/UVES spectrograph, using spectra in the
wavelength ranges 3400-4500 Å, 6800-8200 Å, and 8700-10 000 Å, with
resolving power R ~ 40 000 (blue arm) and R ~ 55 000 (red arm). The
OSMARCS LTE 1D model atmosphere grid was employed, along with the
spectrum synthesis code Turbospectrum. <BR /> Results: We have derived
abundances of the light elements Li, C, and N, the α-elements Mg,
Si, S, Ca, and Ti, the odd-Z elements Al, K, and Sc, the iron-peak
elements V, Cr, Mn, Fe, Co, and Ni, and the trans-iron elements from
the first peak (Sr, Y, Zr, Mo, Ru, and Pd), the second peak (Ba, La,
Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb), the third peak (Os
and Ir, as upper limits), and the actinides (Th) regions. The results
are compared with values for these elements for r-II and "normal"
very and extremely metal-poor stars reported in the literature, ages
based on radioactive chronometry are explored using different models,
and a number of conclusions about the r-process and the r-I stars
are presented. Hydrodynamical models were used for some elements,
and general behaviors for the 3D corrections were presented. Although
the abundance ratios of the second r-process peak elements (usually
associated with the main r-process) are nearly identical for r-I
and r-II stars, the first r-process peak abundance ratios (probably
associated with the weak r-process) are more enhanced in r-I stars than
in r-II stars, suggesting that differing nucleosynthesis pathways were
followed by stars belonging to these two different classifications. <P
/>Observations obtained with the VLT, at the European Southern
Observatory, Paranal, Chile, under proposal 080.D-0194(A)
(PI:V. Hill).Appendix A is available in electronic form at <A
href="http://www.aanda.org/10.1051/0004-6361/201423826/olm">http://www.aanda.org</A>
---------------------------------------------------------
Title: Abundances of lithium, oxygen, and sodium in the turn-off
stars of Galactic globular cluster 47 Tucanae
Authors: Dobrovolskas, V.; Kučinskas, A.; Bonifacio, P.; Korotin,
S. A.; Steffen, M.; Sbordone, L.; Caffau, E.; Ludwig, H. -G.; Royer,
F.; Prakapavičius, D.
2014A&A...565A.121D Altcode: 2013arXiv1311.1072D
Context. The cluster 47 Tuc is among the most metal-rich Galactic
globular clusters and its metallicity is similar to that of metal-poor
disc stars and open clusters. Like other globular clusters, it
displays variations in the abundances of elements lighter than Si,
which is generally interpreted as evidence of the presence of multiple
stellar populations. <BR /> Aims: We aim to determine abundances of
Li, O, and Na in a sample of of 110 turn-off (TO) stars, in order
to study the evolution of light elements in this cluster and to put
our results in perspective with observations of other globular and
open clusters, as well as with field stars. <BR /> Methods: We use
medium resolution spectra obtained with the GIRAFFE spectrograph at
the ESO 8.2 m Kueyen VLT telescope and use state of the art 1D model
atmospheres and NLTE line transfer to determine the abundances. We
also employ CO<SUP>5</SUP>BOLD hydrodynamical simulations to assess
the impact of stellar granulation on the line formation and inferred
abundances. <BR /> Results: Our results confirm the existence of
Na-O abundance anti-correlation and hint towards a possible Li-O
anti-correlation in the TO stars of 47 Tuc. At the same time,
we find no convincing evidence supporting the existence of Li-Na
correlation. The obtained 3D NLTE mean lithium abundance in a sample
of 94 TO stars where Li lines were detected reliably, ⟨A(Li)<SUB>3D
NLTE</SUB>⟩ = 1.78 ± 0.18 dex, appears to be significantly lower
than what is observed in other globular clusters. At the same time,
star-to-star spread in Li abundance is also larger than seen in other
clusters. The highest Li abundance observed in 47 Tuc is about 0.1
dex lower than the lowest Li abundance observed among the un-depleted
stars of the metal-poor open cluster NGC 2243. <BR /> Conclusions: The
correlations/anti-correlations among light element abundances confirm
that chemical enrichment history of 47 Tuc was similar to that of other
globular clusters, despite the higher metallicity of 47 Tuc. The lithium
abundances in 47 Tuc, when put into context with observations in other
clusters and field stars, suggest that stars that are more metal-rich
than [Fe/H] ~ -1.0 experience significant lithium depletion during
their lifetime on the main sequence, while the more metal-poor stars
do not. Rather strikingly, our results suggest that initial lithium
abundance with which the star was created may only depend on its age
(the younger the star, the higher its Li content) and not on its
metallicity. <P />Appendices are available in electronic form at <A
href="http://www.aanda.org/10.1051/0004-6361/201322868/olm">http://www.aanda.org</A>
---------------------------------------------------------
Title: A super lithium-rich red-clump star in the open cluster
Trumpler 5
Authors: Monaco, L.; Boffin, H. M. J.; Bonifacio, P.; Villanova, S.;
Carraro, G.; Caffau, E.; Steffen, M.; Ahumada, J. A.; Beletsky, Y.;
Beccari, G.
2014A&A...564L...6M Altcode: 2014arXiv1403.6461M
Context. The existence of lithium-rich low-mass red giant stars still
represents a challenge for stellar evolution models. Stellar clusters
are privileged environments for this kind of investigation. <BR />
Aims: To investigate the chemical abundance pattern of the old open
cluster Trumpler 5, we observed a sample of four red-clump stars with
high-resolution optical spectrographs. One of them (#3416) reveals
extremely strong lithium lines in its spectrum. <BR /> Methods:
One-dimensional, local thermodynamic equilibrium analysis was
performed on the spectra of the observed stars. A 3D-NLTE analysis
was performed to derive the lithium abundance of star #3416. <BR />
Results: Star #3416 is super Li-rich with A(Li) = 3.75 dex. The lack
of <SUP>6</SUP>Li enrichment (<SUP>6</SUP>Li/<SUP>7</SUP>Li <
2%), the low carbon isotopic ratio (<SUP>12</SUP>C/<SUP>13</SUP>C =
14 ± 3), and the lack of evidence for radial velocity variation
or enhanced rotational velocity (vsini = 2.8 km s<SUP>-1</SUP>)
all suggest that lithium production has occurred in this star
through the Cameron & Fowler mechanism. <BR /> Conclusions:
We identified a super Li-rich core helium-burning, red-clump star
in an open cluster. Internal production is the most likely cause
of the observed enrichment. Given the expected short duration of a
star's Li-rich phase, enrichment is likely to have occurred at the
red clump or in the immediately preceding phases, namely during the
He-flash at the tip of the red giant branch (RGB) or while ascending
the brightest portion of the RGB. <P />Based on observations made
with ESO Telescopes at the La Silla Paranal Observatory under program
ID 088.D-0045(A).Appendix A is available in electronic form at <A
href="http://www.aanda.org/10.1051/0004-6361/201323348/olm">http://www.aanda.org</A>
---------------------------------------------------------
Title: MyGIsFOS: an automated code for parameter determination and
detailed abundance analysis in cool stars
Authors: Sbordone, L.; Caffau, E.; Bonifacio, P.; Duffau, S.
2014A&A...564A.109S Altcode: 2013arXiv1311.5566S
Context. The current and planned high-resolution, high-multiplexity
stellar spectroscopic surveys, as well as the swelling amount
of underutilized data present in public archives, have led to
an increasing number of efforts to automate the crucial but slow
process of retrieving stellar parameters and chemical abundances from
spectra. <BR /> Aims: We present MyGIsFOS<SUP>1</SUP>, a code designed
to derive atmospheric parameters and detailed stellar abundances from
medium- to high-resolution spectra of cool (FGK) stars. We describe
the general structure and workings of the code, present analyses of
a number of well-studied stars representative of the parameter space
MyGIsFOS is designed to cover, and give examples of the exploitation
of MyGIsFOS very fast analysis to assess uncertainties through Monte
Carlo tests. <BR /> Methods: MyGIsFOS aims to reproduce a "traditional"
manual analysis by fitting spectral features for different elements
against a precomputed grid of synthetic spectra. The lines of Fe
i and Fe ii can be employed to determine temperature, gravity,
microturbulence, and metallicity by iteratively minimizing the
dependence of Fe i abundance from line lower energy and equivalent
width, and imposing Fe i-Fe ii ionization equilibrium. Once parameters
are retrieved, detailed chemical abundances are measured from lines of
other elements. <BR /> Results: MyGIsFOS replicates closely the results
obtained in similar analyses on a set of well-known stars. It is also
quite fast, performing a full parameter determination and detailed
abundance analysis in about two minutes per star on a mainstream
desktop computer. Currently, its preferred field of application
are high-resolution and/or large spectral coverage data (e.g.,
UVES, X-shooter, HARPS, Sophie). <P />My God It's Full Of Stars,
<A href="http://mygisfos.obspm.fr">http://mygisfos.obspm.fr</A>
---------------------------------------------------------
Title: r-Process abundances in metal-poor Galactic halo stars
Authors: Siqueira-Mello, C.; Barbuy, B.; Spite, M.; Spite, F.; Caffau,
E.; Hill, V.; Wanajo, S.; François, P.; Bonifacio, P.; Cayrel, R.
2014MmSAI..85..232S Altcode:
The site of the r-process is not completely defined, and several
models try to explain the origin of the trans-Fe elements. Observed
abundances are the best clues to bring some light to this multiplicity
of possible mechanisms, and the extremely metal-poor (EMP) Galactic
halo stars have a special role in this problem. In this contribution
we present the solution of a long-standing problem about the origin
of the heavy elements in the metal-poor halo subgiant star HD 140283,
and its correlation with the Truran's theory. Next, we describe the
results obtained with the EMP r-II star CS 31082-001 in the frame of
the ESO Large Program “First Stars”. Using STIS/HST observations we
provide abundances for elements never presented before in this stars,
making CS 31082-001 the most complete r-II object studied, with a total
of 37 detections of neutron-capture elements. Finally, we present the
results obtained from a sample of seven r-I stars, showing how those
objects can help us solving the heavy elements problem. Conclusions
are also described.
---------------------------------------------------------
Title: 3D modeling of stellar atmospheres and the impact on the
understanding of the reliability of elemental abundances in stars
as tracers of galactic chemical evolution
Authors: Ludwig, H. -G.; Steffen, M.; Bonifacio, P.; Caffau, E.;
Kučinskas, A.; Freytag, B.
2014IAUS..298..343L Altcode:
We present a critical review of the construction of 3D model atmospheres
with emphasis on modeling challenges. We discuss the basic physical
processes which give rise to the effects which set 3D models apart
from 1D standard models. We consider elemental abundances derived
from molecular features, and the determination of the microturbulence
with 3D models. The examples serve as illustration of the limitations
inherent to 1D, however, also to 3D modeling. We find that 3D models
can provide constraints on the microturbulence parameter, and predict
substantial corrections for abundances derived from molecular species.
---------------------------------------------------------
Title: Abundance analysis of three metal poor stars: CS 22166-0030,
CS 22186-0005, and CS 30344-0033
Authors: Çalışkan, Şeyma; Caffau, Elisabetta; Bonifacio, Piercarlo;
Sbordone, Luca; Albayrak, Berahitdin
2014IAUS..298..381C Altcode:
We present the abundance analysis of three very metal poor stars,
CS 22166-0030 ([Fe/H]=-2.96), CS 22186-0005 ([Fe/H]=-2.70), and CS
30344-0033 ([Fe/H]=-2.90). Our study is based on high resolution spectra
which were obtained from SARG (on TNG), HARPS (on 3.6m), and UVES (on
VLT) spectrographs and one-dimensional ATLAS9 model atmospheres. We
derived the abundances for 2, 9, and 16 atomic species in the spectrum
of CS 22166-0030, CS 22186-0005, and CS 30344-0033, respectively. The
Na and Mg abundances of CS 22166-0030 are highly under-abundant with
respect to the solar values. The abundance patterns of CS 22186-0005
and CS 30344-0033 are consistent with the other halo stars within
abundance uncertainties.
---------------------------------------------------------
Title: Strontium in the era of Gaia and LAMOST
Authors: Hansen, Camilla J.; Caffau, Elisabetta; Bergemann, Maria
2014IAUS..298..409H Altcode:
The formation and evolution of the heavy neutron-capture elements (Z
> 37) are to date not well understood. Therefore, abundance and
galactic chemical evolution (GCE) studies of these heavy elements
may carry key information to this open question. Strontium (Sr) is
one of the two heavy elements (Sr and Ba) that show intrinsically very
strong absorption lines even in extremely metal-poor stars (and remains
detectable at low spectral resolution). Hence, the 4077 Å Sr II line
provides a unique insight into the behaviour of heavy neutron-capture
elements at all metallicities and resolutions. Here the focus is
on strontium, its 3D and NLTE (non-local thermodynamic equilibrium)
corrections, as well as chemical evolution.
---------------------------------------------------------
Title: The first generations of stars
Authors: Caffau, E.; Gallagher, A.; Bonifacio, P.; Cayrel, R.;
Christlieb, N.; Clark, P. C.; Francois, P.; Glover, S.; Klessen,
R. S.; Koch, A.; Ludwig, H. G.; Monaco, L.; Plez, B.; Sbordone, L.;
Spite, M.; Spite, F.; Steffen, M.; Zaggia, S.
2014nic..confE..53C Altcode: 2014PoS...204E..53C
No abstract at ADS
---------------------------------------------------------
Title: TOPoS: chemical study of extremely metal-poor stars.
Authors: Caffau, E.; Sbordone, L.; Bonifacio, P.; Cayrel, R.;
Christlieb, N.; Clark, P.; François, P.; Glover, S.; Klessen, R.;
Koch, A.; Ludwig, H. -G.; Monaco, L.; Plez, B.; Spite, F.; Spite,
M.; Steffen, M.; Zaggia, S.
2014MmSAI..85..222C Altcode:
The extremely metal-poor (EMP) stars hold in their atmospheres
the fossil record of the chemical composition of the early phases
of the Galactic evolution. The chemical analysis of such objects
provides important constraints on these early phases. EMP stars
are very rare objects; to dig them out, large amounts of data have
to be processed. With an automatic procedure, we analysed objects
with colours of Turn-Off stars from the Sloan Digital Sky Survey to
select a sample of good candidate EMP stars. In the latest years,
we observed a sample of these candidates with X-Shooter and UVES,
and we have an ongoing ESO large programme to use these spectrographs
to observe EMP stars. I will report here the results on metallicity
and Strontium abundance. <P />Based on observations obtained at ESO
Paranal Observatory, programme 189.D-0165(A)
---------------------------------------------------------
Title: 6Li/7Li isotopic ratio in the most metal-poor binary
CS22876-032
Authors: Gonzalez-Hernandez, J.; Caffau, E.; Ludwig, H. G.; Bonifacio,
P.; Steffen, M.; Monaco, L.; Cayrel, R.
2014nic..confE..23G Altcode: 2014PoS...204E..23G
No abstract at ADS
---------------------------------------------------------
Title: High-Resolution Abundance Analysis of Very Metal-Poor R-I Stars
Authors: Siqueira Mello, C.; Hill, V.; Barbuy, B.; Spite, M.; Spite,
F.; Beers, T.; Caffau, E.; Bonifacio, P.; Cayrel, R.; Francois, P.;
Schatz, H.; Wanajo, S.
2014nic..confE.157S Altcode: 2014PoS...204E.157S
No abstract at ADS
---------------------------------------------------------
Title: Isotope spectroscopy
Authors: Caffau, E.; Steffen, M.; Bonifacio, P.; Ludwig, H. -G.;
Monaco, L.; Lo Curto, G.; Kamp, I.
2014AN....335...59C Altcode: 2013arXiv1310.6058C
The measurement of isotopic ratios provides a privileged insight
both into nucleosynthesis and into the mechanisms operating in
stellar envelopes, such as gravitational settling. In this article,
we give a few examples of how isotopic ratios can be determined from
high-resolution, high-quality stellar spectra. We consider examples of
the lightest elements, H and He, for which the isotopic shifts are very
large and easily measurable, and examples of heavier elements for which
the determination of isotopic ratios is more difficult. The presence
of <SUP>6</SUP>Li in the stellar atmospheres causes a subtle extra
depression in the red wing of the <SUP>7</SUP>Li 670.7 nm doublet which
can only be detected in spectra of the highest quality. But even with
the best spectra, the derived <SUP>6</SUP>Li abundance can only be as
good as the synthetic spectra used for their interpretation. It is now
known that 3D non-LTE modelling of the lithium spectral line profiles
is necessary to account properly for the intrinsic line asymmetry,
which is produced by convective flows in the atmospheres of cool stars,
and can mimic the presence of <SUP>6</SUP>Li. We also discuss briefly
the case of the carbon isotopic ratio in metal-poor stars, and provide a
new determination of the nickel isotopic ratios in the solar atmosphere.
---------------------------------------------------------
Title: X-shooter GTO: evidence for a population of extremely
metal-poor, alpha-poor stars
Authors: Caffau, E.; Bonifacio, P.; François, P.; Sbordone, L.;
Spite, M.; Monaco, L.; Plez, B.; Spite, F.; Zaggia, S.; Ludwig,
H. -G.; Cayrel, R.; Molaro, P.; Randich, S.; Hammer, F.; Hill, V.
2013A&A...560A..15C Altcode: 2013arXiv1309.4913C
Context. The extremely metal-poor stars are the direct descendants
of the first generation stars. They carry the chemical signature
of the pristine Universe at the time they formed, shortly after the
Big Bang. <BR /> Aims: We aim to derive information about extremely
metal-poor stars from their observed spectra. <BR /> Methods: Four
extremely metal-poor stars were selected from the Sloan Digital Sky
Survey (SDSS) and observed during the guaranteed observing time of
X-shooter. The X-shooter spectra were analysed using an automatic code,
MyGIsFOS, which is based on a traditional analysis method. It makes
use of a synthetic grid computed from one-dimensional, plane-parallel,
hydrostatic model atmospheres. <BR /> Results: The low metallicity
derived from the SDSS spectra is confirmed here. Two kinds of stars
are found. Two stars are confirmed to be extremely metal-poor, with no
evidence of any enhancement in carbon. The two other stars are strongly
enhanced in carbon. We could not derive iron abundance for one of them,
while [Ca/H] is below -4.5. Two of the stars are members of the rare
population of extremely metal-poor stars low in alpha elements. <P
/>Based on observations obtained at ESO Paranal Observatory, GTO
programme 089.D-0039.
---------------------------------------------------------
Title: TOPoS. I. Survey design and analysis of the first sample
Authors: Caffau, E.; Bonifacio, P.; Sbordone, L.; François, P.;
Monaco, L.; Spite, M.; Plez, B.; Cayrel, R.; Christlieb, N.; Clark,
P.; Glover, S.; Klessen, R.; Koch, A.; Ludwig, H. -G.; Spite, F.;
Steffen, M.; Zaggia, S.
2013A&A...560A..71C Altcode: 2013arXiv1310.6963C
Context. The metal-weak tail of the metallicity distribution function
(MDF) of the Galactic Halo stars contains crucial information on the
formation mode of the first generation of stars. To determine this
observationally, it is necessary to observe large numbers of extremely
metal-poor stars. <BR /> Aims: We present here the Turn-Off Primordial
Stars survey (TOPoS) that is conducted as an ESO Large Programme at the
VLT. This project has four main goals: (i) to understand the formation
of low-mass stars in a low-metallicity gas: determine the metal-weak
tail of the halo MDF below [M/H] = -3.5; in particular, we aim at
determining the critical metallicity, that is the lowest metallicity
sufficient for the formation of low-mass stars; (ii) to determine in
extremely metal-poor stars the relative abundances of the elements that
are the signature of the massive first stars; (iii) to determine the
trend of the lithium abundance at the time when the Galaxy formed; and
(iv) to derive the fraction of C-enhanced extremely metal-poor stars
with respect to normal extremely metal-poor stars. The large number of
stars observed in the SDSS provides a good sample of candidate stars
at extremely low metallicity. <BR /> Methods: Candidates with turn-off
colours down to magnitude g = 20 were selected from the low-resolution
spectra of SDSS by means of an automated procedure. X-Shooter has the
potential of performing the necessary follow-up spectroscopy, providing
accurate metallicities and abundance ratios for several key elements
for these stars. <BR /> Results: We present here the stellar parameters
of the first set of stars. The nineteen stars range in iron abundance
between -4.1 and -2.9 dex relative to the Sun. Two stars have a high
radial velocity and, according to our estimate of their kinematics,
appear to be marginally bound to the Galaxy and are possibly accreted
from another galaxy. <P />Based on observations obtained at ESO Paranal
Observatory, GTO programme 189.D-0165(A).
---------------------------------------------------------
Title: Stellar granulation as seen in disk-integrated
intensity. II. Theoretical scaling relations compared with
observations
Authors: Samadi, R.; Belkacem, K.; Ludwig, H. -G.; Caffau, E.;
Campante, T. L.; Davies, G. R.; Kallinger, T.; Lund, M. N.; Mosser,
B.; Baglin, A.; Mathur, S.; Garcia, R. A.
2013A&A...559A..40S Altcode: 2013arXiv1309.1488S
Context. A large set of stars observed by CoRoT and Kepler shows clear
evidence for the presence of a stellar background, which is interpreted
to arise from surface convection, i.e., granulation. These observations
show that the characteristic time-scale (τ<SUB>eff</SUB>) and the
root-mean-square (rms) brightness fluctuations (σ) associated with the
granulation scale as a function of the peak frequency (ν<SUB>max</SUB>)
of the solar-like oscillations. <BR /> Aims: We aim at providing a
theoretical background to the observed scaling relations based on a
model developed in Paper I. <BR /> Methods: We computed for each 3D
model the theoretical power density spectrum (PDS) associated with
the granulation as seen in disk-integrated intensity on the basis of
the theoretical model published in Paper I. For each PDS we derived
the associated characteristic time (τ<SUB>eff</SUB>) and the rms
brightness fluctuations (σ) and compared these theoretical values with
the theoretical scaling relations derived from the theoretical model and
the measurements made on a large set of Kepler targets. <BR /> Results:
We derive theoretical scaling relations for τ<SUB>eff</SUB> and σ,
which show the same dependence on ν<SUB>max</SUB> as the observed
scaling relations. In addition, we show that these quantities also
scale as a function of the turbulent Mach number (ℳ<SUB>a</SUB>)
estimated at the photosphere. The theoretical scaling relations
for τ<SUB>eff</SUB> and σ match the observations well on a
global scale. Quantitatively, the remaining discrepancies with the
observations are found to be much smaller than previous theoretical
calculations made for red giants. <BR /> Conclusions: Our modelling
provides additional theoretical support for the observed variations
of σ and τ<SUB>eff</SUB> with ν<SUB>max</SUB>. It also highlights
the important role of ℳ<SUB>a</SUB> in controlling the properties
of the stellar granulation. However, the observations made with
Kepler on a wide variety of stars cannot confirm the dependence
of our scaling relations on ℳ<SUB>a</SUB>. Measurements of the
granulation background and detections of solar-like oscillations in a
statistically sufficient number of cool dwarf stars will be required
for confirming the dependence of the theoretical scaling relations with
ℳ<SUB>a</SUB>. <P />Appendices are available in electronic form at
<A href="http://www.aanda.org">http://www.aanda.org</A>
---------------------------------------------------------
Title: Three-dimensional hydrodynamical CO<SUP>5</SUP>BOLD model
atmospheres of red giant stars. III. Line formation in the atmospheres
of giants located close to the base of the red giant branch
Authors: Dobrovolskas, V.; Kučinskas, A.; Steffen, M.; Ludwig,
H. -G.; Prakapavičius, D.; Klevas, J.; Caffau, E.; Bonifacio, P.
2013A&A...559A.102D Altcode: 2013arXiv1310.7791D
<BR /> Aims: We utilize state-of-the-art three-dimensional (3D)
hydrodynamical and classical 1D stellar model atmospheres to study
the influence of convection on the formation properties of various
atomic and molecular spectral lines in the atmospheres of four red
giant stars, located close to the base of the red giant branch, RGB
(T<SUB>eff</SUB> ≈ 5000 K, log g = 2.5), and characterized by four
different metallicities, [M/H] = 0.0, -1.0, -2.0, -3.0. <BR /> Methods:
The role of convection in the spectral line formation is assessed with
the aid of abundance corrections, i.e., the differences in abundances
predicted for a given equivalent width of a particular spectral line
with the 3D and 1D model atmospheres. The 3D hydrodynamical and
classical 1D model atmospheres used in this study were calculated
with the CO<SUP>5</SUP>BOLD and 1D LHD codes, respectively. Identical
atmospheric parameters, chemical composition, equation of state, and
opacities were used with both codes, therefore allowing a strictly
differential analysis of the line formation properties in the 3D and 1D
models. <BR /> Results: We find that for lines of certain neutral atoms,
such as Mg i, Ti i, Fe i, and Ni i, the abundance corrections strongly
depend both on the metallicity of a given model atmosphere and the line
excitation potential, χ. While abundance corrections for all lines of
both neutral and ionized elements tend to be small at solar metallicity
(≤±0.1 dex), for lines of neutral elements with low ionization
potential and low-to-intermediate χ they quickly increase with
decreasing metallicity, reaching in their extremes -0.6 to -0.8 dex. In
all such cases the large abundance corrections are due to horizontal
temperature fluctuations in the 3D hydrodynamical models. Lines of
neutral elements with higher ionization potentials (E<SUB>ion</SUB>
≳ 10 eV) generally behave very similarly to lines of ionized elements
characterized by low ionization potentials (E<SUB>ion</SUB> ≲ 6
eV). In the latter case, the abundance corrections are small (generally,
≤±0.1 dex) and are caused by approximately equal contributions
from the horizontal temperature fluctuations and differences between
the temperature profiles in the 3D and 1D model atmospheres. Abundance
corrections of molecular lines are very sensitive to the metallicity of
the underlying model atmosphere and may be larger (in absolute value)
than ~-0.5 dex at [M/H] = -3.0 (~-1.5 dex in the case of CO). At fixed
metallicity and excitation potential, the abundance corrections show
little variation within the wavelength range studied here, 400-1600
nm. We also find that an approximate treatment of scattering in the
3D model calculations (i.e., ignoring the scattering opacity in the
outer, optically thin, atmosphere) leads to abundance corrections
that are altered by less than ~0.1 dex, both for atomic and molecular
(CO) lines, with respect to the model where scattering is treated as
true absorption throughout the entire atmosphere, with the largest
differences for the resonance and low-excitation lines. <P />Appendices
and Figs. 3, 5, 6, 8, 9, 11 are available in electronic form at <A
href="http://www.aanda.org">http://www.aanda.org</A>
---------------------------------------------------------
Title: Granulation properties of giants, dwarfs, and white dwarfs
from the CIFIST 3D model atmosphere grid
Authors: Tremblay, P. -E.; Ludwig, H. -G.; Freytag, B.; Steffen, M.;
Caffau, E.
2013A&A...557A...7T Altcode: 2013arXiv1307.2810T
Three-dimensional model atmospheres for giants, dwarfs, and white
dwarfs, computed with the CO5BOLD code and part of the CIFIST grid,
have been used for spectroscopic and asteroseismic studies. Unlike
existing plane-parallel 1D structures, these simulations predict
the spatially and temporally resolved emergent intensity so that
granulation can be analysed, which provides insights on how convective
energy transfer operates in stars. The wide range of atmospheric
parameters of the CIFIST 3D simulations (3600 < T<SUB>eff</SUB>
(K) < 13 000 and 1 < log g < 9) allows the comparison of
convective processes in significantly different environments. We
show that the relative intensity contrast is correlated with both
the Mach and Péclet numbers in the photosphere. The horizontal size
of granules varies between 3 and 10 times the local pressure scale
height, with a tight correlation between the factor and the Mach
number of the flow. Given that convective giants, dwarfs, and white
dwarfs cover the same range of Mach and Péclet numbers, we conclude
that photospheric convection operates in a very similar way in those
objects. <P />Table 1 and Appendix A are available in electronic form
at <A href="http://www.aanda.org">http://www.aanda.org</A>
---------------------------------------------------------
Title: Reanalysis of the FEROS observations of HIP 11952
Authors: Müller, A.; Roccatagliata, V.; Henning, Th.; Fedele, D.;
Pasquali, A.; Caffau, E.; Rodríguez-Ledesma, M. V.; Mohler-Fischer,
M.; Seemann, U.; Klement, R. J.
2013A&A...556A...3M Altcode: 2013arXiv1307.5072M
<BR /> Aims: We reanalyze FEROS observations of the star HIP 11952 to
reassess the existence of the proposed planetary system. <BR /> Methods:
The radial velocity of the spectra were measured by cross-correlating
the observed spectrum with a synthetic template. We also analyzed a
large dataset of FEROS and HARPS archival data of the calibrator HD
10700 spanning over more than five years. We compared the barycentric
velocities computed by the FEROS and HARPS pipelines. <BR /> Results:
The barycentric correction of the FEROS-DRS pipeline was found to
be inaccurate and to introduce an artificial one-year period with a
semi-amplitude of 62 m s<SUP>-1</SUP>. Thus the reanalysis of the
FEROS data does not support the existence of planets around HIP
11952. <P />Based on data products from observations made with ESO
Telescopes at the La Silla Paranal Observatory under programme ID
60.A-9036, 072.C-0488, 072.C-0513, 073.C-0784, 074.C-0012, 074.D-0380,
075.C-0234, 075.D-0760, 076.C-0073, 076.C-0878, 077.A-9009, 077.C-0138,
077.C-0192, 077.C-0530, 078.A-9048, 078.C-0378, 078.C-0833, 079.A-9006,
079.A-9017, 079.C-0170, 079.C-0681, 080.A-9005, 080.A-9021, 080.C-0032,
082.A-9011, 082.C-0315, 083.A-9011, 084.A-9003, 084.A-9003, 084.A-9004,
084.A-9004, 084.A-9011, 085.A-9027, 085.A-9027, 085.C-0557, 086.A-9006,
086.A-9006, 086.A-9014, 086.A-9014, 086.D-0460, 087.A-9014, 087.C-0476,
088.A-9007, 088.A-9007.Appendices are available in electronic form at
<A href="http://www.aanda.org">http://www.aanda.org</A>
---------------------------------------------------------
Title: The photospheric solar oxygen project. II. Non-concordance
of the oxygen abundance derived from two forbidden lines
Authors: Caffau, E.; Ludwig, H. -G.; Malherbe, J. -M.; Bonifacio,
P.; Steffen, M.; Monaco, L.
2013A&A...554A.126C Altcode: 2013arXiv1305.1763C
Context. In the Sun, the two forbidden [O i] lines at 630 and 636 nm
were previously found to provide discrepant oxygen abundances. <BR
/> Aims: We investigate whether this discrepancy is peculiar to the
Sun or whether it is also observed in other stars. <BR /> Methods:
We make use of high-resolution, high signal-to-noise ratio spectra of
four dwarf to turn-off stars, five giant stars, and one sub-giant star
observed with THEMIS, HARPS, and UVES to investigate the coherence of
the two lines. <BR /> Results: The two lines provide oxygen abundances
that are consistent, within observational errors, in all the giant
stars examined by us. On the other hand, for the two dwarf stars for
which a measurement was possible, for Procyon, and for the sub-giant
star Capella, the 636 nm line provides systematically higher oxygen
abundances, as already seen for the Sun. <BR /> Conclusions: The
only two possible reasons for the discrepancy are a serious error
in the oscillator strength of the Ni i line blending the 630 nm line
or the presence of an unknown blend in the 636 nm line, which makes
the feature stronger. The CN lines blending the 636 nm line cannot
be responsible for the discrepancy. The Ca i autoionisation line, on
the red wing of which the 636 nm line is formed, is not well modelled
by our synthetic spectra. However, a better reproduction of this line
would result in even higher abundances from the 636 nm, thus increasing
the discrepancy. <P />Based on observations collected at ESO Paranal
Observatory, Programme 182.D-5053(A).
---------------------------------------------------------
Title: Carbon-enhanced metal-poor stars: the most pristine objects?
Authors: Spite, M.; Caffau, E.; Bonifacio, P.; Spite, F.; Ludwig,
H. -G.; Plez, B.; Christlieb, N.
2013A&A...552A.107S Altcode: 2013arXiv1303.1791S
Context. Carbon-enhanced metal-poor stars (CEMP) form a significant
proportion of the metal-poor stars, their origin is not well understood,
and this carbon-enhancement appears in stars that exhibit different
abundance patterns. <BR /> Aims: Three very metal-poor C-rich turnoff
stars were selected from the SDSS survey, observed with the ESO VLT
(UVES) to precisely determine the element abundances. In turnoff
stars (unlike giants) the carbon abundance has not been affected by
mixing with deep layers and is therefore easier to interpret. <BR />
Methods: The analysis was performed with one dimensional (1D) local
thermodynamical equilibrium (LTE) static model atmospheres. When
available, non-LTE corrections were applied to the classical LTE
abundances. The 3D effects on the CH and CN molecular bands were
computed using hydrodynamical simulations of the stellar atmosphere
(CO<SUP>5</SUP>BOLD) and are found to be very important. <BR />
Results: To facilitate a comparison with previous results, only
1D abundances are used in the discussion. The abundances (or upper
limits) of the elements enable us to place these stars in different
CEMP classes. The carbon abundances confirm the existence of a plateau
at A(C)= 8.25 for [Fe/H] ≥ -3.4. The most metal-poor stars ([Fe/H]
< -3.4) have significantly lower carbon abundances, suggesting a
lower plateau at A(C) ≈ 6.5. Detailed analyses of a larger sample
of very low metallicity carbon-rich stars are required to confirm
(or refute) this possible second plateau and specify the behavior of
the CEMP stars at very low metallicity. <P />Based on observations
obtained with the ESO Very Large Telescope at Paranal Observatory,
Chile (ID 087.D-0123(A).Table 5 is available in electronic form at
<A href="http://www.aanda.org">http://www.aanda.org</A>
---------------------------------------------------------
Title: Fluorine Abundances of Galactic Low-metallicity Giants
Authors: Li, H. N.; Ludwig, H. -G.; Caffau, E.; Christlieb, N.;
Zhao, G.
2013ApJ...765...51L Altcode: 2013arXiv1302.3928L
With abundances and 2σ upper limits of fluorine (F) in seven metal-poor
field giants, nucleosynthesis of stellar F at low metallicity is
discussed. The measurements are derived from the HF(1-0) R9 line at
23358 Å using near-infrared K-band high-resolution spectra obtained
with CRIRES at the Very Large Telescope. The sample reaches lower
metallicities than previous studies on F of field giants, ranging from
[Fe/H] = -1.56 down to -2.13. Effects of three-dimensional model
atmospheres on the derived F and O abundances are quantitatively
estimated and shown to be insignificant for the program stars. The
observed F yield in the form of [F/O] is compared with two sets of
Galactic chemical evolution models, which quantitatively demonstrate
the contribution of Type II supernova (SN II) ν-process and asymptotic
giant branch/Wolf-Rayet stars. It is found that at this low-metallicity
region, models cannot well predict the observed distribution of
[F/O], while the observations are better fit by models considering
an SN II ν-process with a neutrino energy of E <SUB>ν</SUB> = 3
× 10<SUP>53</SUP> erg. Our sample contains HD 110281, a retrograde
orbiting low-α halo star, showing a similar F evolution as globular
clusters. This supports the theory that such halo stars are possibly
accreted from dwarf galaxy progenitors of globular clusters in the halo.
---------------------------------------------------------
Title: Is the Sun Lighter than the Earth? Isotopic CO in the
Photosphere, Viewed through the Lens of Three-dimensional Spectrum
Synthesis
Authors: Ayres, Thomas R.; Lyons, J. R.; Ludwig, H. -G.; Caffau, E.;
Wedemeyer-Böhm, S.
2013ApJ...765...46A Altcode: 2013arXiv1301.5281A
We consider the formation of solar infrared (2-6 μm) rovibrational
bands of carbon monoxide (CO) in CO5BOLD 3D convection models,
with the aim of refining abundances of the heavy isotopes of carbon
(<SUP>13</SUP>C) and oxygen (<SUP>18</SUP>O, <SUP>17</SUP>O), to
compare with direct capture measurements of solar wind light ions
by the Genesis Discovery Mission. We find that previous, mainly 1D,
analyses were systematically biased toward lower isotopic ratios (e.g.,
R <SUB>23</SUB> ≡ <SUP>12</SUP>C/<SUP>13</SUP>C), suggesting an
isotopically "heavy" Sun contrary to accepted fractionation processes
that were thought to have operated in the primitive solar nebula. The
new 3D ratios for <SUP>13</SUP>C and <SUP>18</SUP>O are R <SUB>23</SUB>
= 91.4 ± 1.3 (R <SUB>⊕</SUB> = 89.2) and R <SUB>68</SUB> =
511 ± 10 (R <SUB>⊕</SUB> = 499), where the uncertainties are
1σ and "optimistic." We also obtained R <SUB>67</SUB> = 2738 ±
118 (R <SUB>⊕</SUB> = 2632), but we caution that the observed
<SUP>12</SUP>C<SUP>17</SUP>O features are extremely weak. The new solar
ratios for the oxygen isotopes fall between the terrestrial values and
those reported by Genesis (R <SUB>68</SUB> = 530, R <SUB>67</SUB> =
2798), although including both within 2σ error flags, and go in the
direction favoring recent theories for the oxygen isotope composition
of Ca-Al inclusions in primitive meteorites. While not a major focus
of this work, we derive an oxygen abundance, epsilon<SUB>O</SUB> ~
603 ± 9 ppm (relative to hydrogen; log epsilon ~ 8.78 on the H =
12 scale). The fact that the Sun is likely lighter than the Earth,
isotopically speaking, removes the necessity of invoking exotic
fractionation processes during the early construction of the inner
solar system.
---------------------------------------------------------
Title: Velocity and abundance precisions for future high-resolution
spectroscopic surveys: A study for 4MOST
Authors: Caffau, E.; Koch, A.; Sbordone, L.; Sartoretti, P.; Hansen,
C. J.; Royer, F.; Leclerc, N.; Bonifacio, P.; Christlieb, N.; Ludwig,
H. -G.; Grebel, E. K.; de Jong, R. S.; Chiappini, C.; Walcher, J.;
Mignot, S.; Feltzing, S.; Cohen, M.; Minchev, I.; Helmi, A.; Piffl,
T.; Depagne, E.; Schnurr, O.
2013AN....334..197C Altcode: 2012arXiv1211.1406C
In preparation for future, large-scale, multi-object, high-resolution
spectroscopic surveys of the Galaxy, we present a series of tests
of the precision in radial velocity and chemical abundances that any
such project can achieve at a 4 m class telescope. We briefly discuss
a number of science cases that aim at studying the chemo-dynamical
history of the major Galactic components (bulge, thin and thick disks,
and halo) - either as a follow-up to the Gaia mission or on their own
merits. Based on a large grid of synthetic spectra that cover the full
range in stellar parameters of typical survey targets, we devise an
optimal wavelength range and argue for a moderately high-resolution
spectrograph. As a result, the kinematic precision is not limited by
any of these factors, but will practically only suffer from systematic
effects, easily reaching uncertainties <1 km s<SUP>-1</SUP>. Under
realistic survey conditions (namely, considering stars brighter than
r=16 mag with reasonable exposure times) we prefer an ideal resolving
power of R∼20 000 on average, for an overall wavelength range (with
a common two-arm spectrograph design) of [395;456.5] nm and [587;673]
nm. We show for the first time on a general basis that it is possible
to measure chemical abundance ratios to better than 0.1 dex for many
species (Fe, Mg, Si, Ca, Ti, Na, Al, V, Cr, Mn, Co, Ni, Y, Ba, Nd, Eu)
and to an accuracy of about 0.2 dex for other species such as Zr, La,
and Sr. While our feasibility study was explicitly carried out for
the 4MOST facility, the results can be readily applied to and used
for any other conceptual design study for high-resolution spectrographs.
---------------------------------------------------------
Title: Amplitudes of solar-like oscillations in red giants: Departures
from the quasi-adiabatic approximation
Authors: Samadi, R.; Belkacem, K.; Dupret, M. -A.; Goupil, M. J.;
Ludwig, H. -G.; Barban, C.; Baudin, F.; Caffau, E.
2013EPJWC..4303008S Altcode:
CoRoT and Kepler measurements reveal us that the amplitudes of
solar-like oscillations detected in red giant stars scale from stars
to stars in a characteristic way. This observed scaling relation
is not yet fully understood but constitutes potentially a powerful
diagnostic about mode physics. Quasi-adiabatic theoretical scaling
relations in terms of mode amplitudes result in systematic and large
differences with the measurements performed for red giant stars. The
use of a non-adiabatic intensity-velocity relation derived from a
non-adiabatic pulsation code significantly reduces the discrepancy
with the CoRoT measurements. The origin of the remaining difference
is still unknown. Departure from adiabatic eigenfunction is a very
likely explanation that is investigated in the present work using a
3D hydrodynamical model of the surface layers of a representative red
giant star.
---------------------------------------------------------
Title: Isotopic CO in the Solar Photosphere, Viewed Through the Lens
of 3D Spectrum Synthesis
Authors: Ayres, T. R.; Lyons, J. R.; Ludwig, H. -G.; Caffau, E.;
Wedemeyer-Bohm, S.
2013LPI....44.3038A Altcode: 2013LPICo1719.3038A
New analyses of CO isotopologue abundances in the solar photosphere
are now consistent with Genesis solar wind results, although ^17O
error bars are still large.
---------------------------------------------------------
Title: ELT-MOS White Paper: Science Overview & Requirements
Authors: Evans, Chris; Puech, Mathieu; Barbuy, Beatriz; Bastian, Nate;
Bonifacio, Piercarlo; Caffau, Elisabetta; Cuby, Jean-Gabriel; Dalton,
Gavin; Davies, Ben; Dunlop, Jim; Flores, Hector; Hammer, Francois;
Kaper, Lex; Lemasle, Bertrand; Morris, Simon; Pentericci, Laura;
Petitjean, Patrick; Schaerer, Daniel; Telles, Eduardo; Welikala,
Niraj; Ziegler, Bodo
2013arXiv1303.0029E Altcode:
The workhorse instruments of the 8-10m class observatories have become
their multi-object spectrographs (MOS), providing comprehensive
follow-up to both ground-based and space-borne imaging. With the
advent of deeper imaging surveys from, e.g., the HST and VISTA, there
are a plethora of spectroscopic targets which are already beyond the
sensitivity limits of current facilities. This wealth of targets
will grow even more rapidly in the coming years, e.g., after the
completion of ALMA, the launch of the JWST and Euclid, and the advent
of the LSST. Thus, one of the key requirements underlying plans for
the next generation of ground-based telescopes, the Extremely Large
Telescopes (ELTs), is for even greater sensitivity for optical and
infrared spectroscopy. Here we revisit the scientific motivation for
a MOS capability on the European ELT, combining updated elements of
science cases advanced from the Phase A instrument studies with new
science cases which draw on the latest results and discoveries. These
science cases address key questions related to galaxy evolution over
cosmic time, from studies of resolved stellar populations in nearby
galaxies out to observations of the most distant galaxies, and are
used to identify the top-level requirements on an 'E-ELT/MOS'. We
argue that several of the most compelling ELT science cases demand MOS
observations, in highly competitive areas of modern astronomy. Recent
technical studies have demonstrated that important issues related to
e.g. sky subtraction and multi-object AO can be solved, making fast-
track development of a MOS instrument feasible. To ensure that ESO
retains world leadership in exploring the most distant objects in the
Universe, galaxy evolution and stellar populations, we are convinced
that a MOS should have high priority in the instrumentation plan for
the E-ELT.
---------------------------------------------------------
Title: Convective line shifts for the Gaia RVS from the CIFIST 3D
model atmosphere grid
Authors: Allende Prieto, C.; Koesterke, L.; Ludwig, H. -G.; Freytag,
B.; Caffau, E.
2013A&A...550A.103A Altcode: 2013arXiv1301.3703A
Context. To derive space velocities of stars along the line of sight
from wavelength shifts in stellar spectra requires accounting for a
number of second-order effects. For most stars, gravitational redshifts,
convective blueshifts, and transverse stellar motion are the dominant
contributors. <BR /> Aims: We provide theoretical corrections for the
net velocity shifts due to convection expected for the measurements
from the Gaia Radial Velocity Spectrometer (RVS). <BR /> Methods: We
used a set of three-dimensional time-dependent simulations of stellar
surface convection computed with CO5BOLD to calculate spectra of
late-type stars in the Gaia RVS range and to infer the net velocity
offset that convective motions will induce in radial velocities
derived by cross-correlation. <BR /> Results: The net velocity shifts
derived by cross-correlation depend both on the wavelength range and
spectral resolution of the observations. Convective shifts for Gaia
RVS observations are less than 0.1 km s<SUP>-1</SUP> for late-K-type
stars, and they increase with stellar mass, reaching about 0.3 km
s<SUP>-1</SUP> or more for early F-type dwarfs. This tendency is the
result of an increase with effective temperature in both temperature
and velocity fluctuations in the line-forming region. Our simulations
also indicate that the net RVS convective shifts can be positive
(i.e. redshifts) in some cases. Overall, the blueshifts weaken
slightly with increasing surface gravity, and are enhanced at low
metallicity. Gravitational redshifts amount to 0.7 km s<SUP>-1</SUP>
and dominate convective blueshifts for dwarfs, but become much
weaker for giants. <P />Appendix A is available in electronic form
at <A href="http://www.aanda.org">http://www.aanda.org</A>Model
spectra from the 1D and 3D calculations are only available
in electronic form at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">cdsarc.u-strasbg.fr</A><A
href="http://130.79.128.5">130.79.128.5</A> or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/550/A103">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/550/A103</A>
---------------------------------------------------------
Title: First stars. XVI. HST/STIS abundances of heavy elements in
the uranium-rich metal-poor star CS 31082-001
Authors: Siqueira Mello, C.; Spite, M.; Barbuy, B.; Spite, F.; Caffau,
E.; Hill, V.; Wanajo, S.; Primas, F.; Plez, B.; Cayrel, R.; Andersen,
J.; Nordström, B.; Sneden, C.; Beers, T. C.; Bonifacio, P.; François,
P.; Molaro, P.
2013A&A...550A.122S Altcode: 2012arXiv1212.0211S
Context. The origin and site(s) of the r-process nucleosynthesis is(are)
still not known with certainty, but complete, detailed r-element
abundances offer our best clues. The few extremely metal-poor (EMP)
stars with large r-element excesses allow us to study the r-process
signatures in great detail, with minimal interference from later stages
of Galactic evolution. CS 31082-001 is an outstanding example of the
information that can be gathered from these exceptional stars. <BR />
Aims: Here we aim to complement our previous abundance determinations
for third-peak r-process elements with new and improved results for
elements of the first and second r-process peaks from near-UV HST/STIS
and optical UVES spectra. These results should provide new insight
into the nucleosynthesis of the elements beyond iron. <BR /> Methods:
The spectra were analyzed by a consistent approach based on an OSMARCS
LTE model atmosphere and the Turbospectrum spectrum synthesis code
to derive abundances of heavy elements in CS 31082-001, and using
updated oscillator strengths from the recent literature. Synthetic
spectra were computed for all lines of the elements of interest
to check for proper line intensities and possible blends in these
crowded spectra. Our new abundances were combined with the best
previous results to provide reliable mean abundances for the first
and second-peak r-process elements. <BR /> Results: We present new
abundances for 23 neutron-capture elements, 6 of which - Ge, Mo,
Lu, Ta, W, and Re - have not been reported before. This makes CS
31082-001 the most completely studied r-II star, with abundances for
a total of 37 neutron-capture elements. We also present the first
NLTE+3D abundance of lead in this star, further constraining the
nature of the r-process. <P />Based on observations made with the
NASA/ESA Hubble Space Telescope (HST) through the Space Telescope
Science Institute, operated by the Association of Universities for
Research in Astronomy, Inc., under NASA contract NAS5-26555; and
with the ESO Very Large Telescope at Paranal Observatory, Chile;
Progr. ID 165.N-0276.Appendix A is available in electronic form at
<A href="http://www.aanda.org">http://www.aanda.org</A>
---------------------------------------------------------
Title: Three-dimensional hydrodynamical CO<SUP>5</SUP>BOLD model
atmospheres of red giant stars. II. Spectral line formation in the
atmosphere of a giant located near the RGB tip
Authors: Kučinskas, A.; Steffen, M.; Ludwig, H. -G.; Dobrovolskas,
V.; Ivanauskas, A.; Klevas, J.; Prakapavičius, D.; Caffau, E.;
Bonifacio, P.
2013A&A...549A..14K Altcode: 2012arXiv1211.7313K
<BR /> Aims: We investigate the role of convection in the formation of
atomic and molecular lines in the atmosphere of a red giant star. For
this purpose we study the formation properties of spectral lines that
belong to a number of astrophysically important tracer elements,
including neutral and singly ionized atoms (Li I, N I, O I, Na I,
Mg I, Al I, Si I, Si II, S I, K I, Ca I, Ca II, Ti I, Ti II, Cr I,
Cr II, Mn I, Fe I, Fe II, Co I, Ni I, Zn I, Sr II, Ba II, and Eu II),
and molecules (CH, CO, C<SUB>2</SUB>, NH, CN, and OH). <BR /> Methods:
We focus our investigation on a prototypical red giant located close to
the red giant branch (RGB) tip (T<SUB>eff</SUB> = 3660 K, log g = 1.0,
[M/H] = 0.0). We used two types of model atmospheres, 3D hydrodynamical
and classical 1D, calculated with the CO<SUP>5</SUP>BOLD and LHD
stellar atmosphere codes, respectively. Both codes share the same
atmospheric parameters, chemical composition, equation of state,
and opacities, which allowed us to make a strictly differential
comparison between the line formation properties predicted in 3D and
1D. The influence of convection on the spectral line formation was
assessed with the aid of 3D-1D abundance corrections, which measure
the difference between the abundances of chemical species derived
with the 3D hydrodynamical and 1D classical model atmospheres. <BR
/> Results: We find that convection plays a significant role in
the spectral line formation in this particular red giant. The
derived 3D-1D abundance corrections rarely exceed ± 0.1 dex when
lines of neutral atoms and molecules are considered, which is in
line with the previous findings for solar-metallicity red giants
located on the lower RGB. The situation is different with lines that
belong to ionized atoms, or to neutral atoms with high ionization
potential. In both cases, the corrections for high-excitation lines
(χ > 8 eV) may amount to Δ<SUB>3D-1D</SUB> ~ -0.4 dex. The
3D-1D abundance corrections generally show a significant wavelength
dependence; in most cases they are smaller in the near-infrared, at
1600-2500 nm. <P />Appendices are available in electronic form at <A
href="http://www.aanda.org">http://www.aanda.org</A>
---------------------------------------------------------
Title: Micro- and macroturbulence predictions from CO5BOLD 3D stellar
atmospheres .
Authors: Steffen, M.; Caffau, E.; Ludwig, H. -G.
2013MSAIS..24...37S Altcode: 2013arXiv1306.4307S
We present an overview of the current status of our efforts to derive
the microturbulence and macroturbulence parameters (xi_mic and xi_mac)
from the CIFIST grid of CO5BOLD 3D model atmospheres as a function
of the basic stellar parameters T_{eff}, log g, and [M/H]. The latest
results for the Sun and Procyon show that the derived microturbulence
parameter depends significantly on the numerical resolution of the
underlying 3D simulation, confirming that `low-resolution' models tend
to underestimate the true value of xi_mic . Extending the investigation
to 12 further simulations with different T_{eff}, log g, and [M/H],
we obtain a first impression of the predicted trend of xi_mic over the
Hertzsprung-Russell diagram: in agreement with empirical evidence,
microturbulence increases towards higher effective temperature and
lower gravity. The metallicity dependence of xi_mic must be interpreted
with care, since it also reflects the deviation between the 1D and 3D
photospheric temperature stratifications that increases systematically
towards lower [M/H].
---------------------------------------------------------
Title: CO5BOLD workshop 2012
Authors: Caffau, E.; Sbordone, L.
2013MSAIS..24....3C Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The influence of convection on the atmospheric structures
and observable properties of red giant stars.
Authors: Kučinskas, A.; Ludwig, H. -G.; Steffen, M.; Dobrovolskas,
V.; Klevas, J.; Prakapavičius, D.; Caffau, E.; Bonifacio, P.
2013MSAIS..24...68K Altcode: 2013arXiv1305.3441K
During the recent years significant progress has been made in the
modeling of red giant atmospheres with the aid of 3D hydrodynamical
model atmosphere codes. In this contribution we provide an overview of
selected results obtained in this context by utilizing 3D hydrodynamical
CO<SUP>5</SUP>BOLD stellar model atmospheres. Hydrodynamical simulations
show that convective motions lead to significant differences in the
atmospheric structures of red giants with respect to those predicted by
the classical 1D model atmospheres. Results of these simulations also
show that in certain cases 1D models fail to reproduce even the average
properties of the 3D hydrodynamical models, such as P-T profiles. Large
horizontal temperature fluctuations in the 3D model atmospheres, as well
as differences between the temperature profiles of the average xtmean
{3D} and 1D models, lead to large discrepancies in the strengths of
spectral lines predicted by the 3D and 1D model atmospheres. This is
especially important in models at lowest metallicities ([M/H]<-2.0)
where the 3D-1D abundance differences may reach (or even exceed) -0.6
dex for lines of neutral atoms and molecules. We also discuss several
simplifications and numerical aspects involved in the present 3D
hydrodynamical modeling of red giant atmospheres, and briefly address
several issues where urgent progress may be needed.
---------------------------------------------------------
Title: Molecular bands in extremely metal-poor stars: Granulation
effects
Authors: Bonifacio, P.; Caffau, E.; Ludwig, H. -G.; Spite, M.; Plez,
B.; Steffen, M.; Spite, F.
2013MSAIS..24..138B Altcode: 2013arXiv1305.2065B
The bands of diatomic molecules are important abundance indicators,
especially in metal-poor stars, where they are still measurable in
metallicity regimes where the atomic lines of their constituting
metallic elements have become vanishingly small. In order to use
them for abundance determinations it is imperative to understand the
formation of these bands. In this contribution we report on our results
obtained using CO^5{BOLD} hydrodynamical simulations. Some effects
that are qualitatively different from what found in 1D computations
are highlighted. Due to the large number of lines that form the bands,
their spectrum synthesis is computationally challenging. We discuss
some of the computational strategies we employed to parallelise the
computation and possible future developments.
---------------------------------------------------------
Title: Signs of atmospheric inhomogeneities in cool stars from
1D-NLTE analysis of iron lines
Authors: Mashonkina, L.; Ludwig, H. -G.; Korn, A.; Sitnova, T.;
Caffau, E.
2013MSAIS..24..120M Altcode: 2013arXiv1303.0357M
For the well studied halo star HD 122563 and the four stars in the
globular cluster NGC 6397, we determine NLTE abundances of iron
using classical plane-parallel model atmospheres. Each star reveals
a discrepancy in abundances between the Fe I lines arising from the
ground state and the other Fe I lines, in qualitative agreement with
the 3D-LTE line formation predictions, however, the magnitude of the
observed effect is a factor of 2 smaller compared with the predicted
one. When ignoring the Fe I low-excitation lines, the NLTE abundances
from the two ionization stages, Fe I and Fe II are consistent in each
investigated star. For the subgiants in NGC 6397, this is only true when
using the cooler effective temperature scale of \citet{Alonso1999}. We
also present full 3D-LTE line formation calculations for some selected
iron lines in the solar and metal-poor 4480/2/-3 models and NLTE
calculations with the corresponding spatial and temporal average
<{3D}> models. The use of the <{3D}> models is justified
only for particular Fe I lines in particular physical conditions. Our
NLTE calculations reproduce well the centre-to-limb variation of
the solar Fe I 7780 Å line, but they are unsuccessful for Fe I 6151
Å. The metal-poor <{3D}> model was found to be adequite for
the strong Fe I 5166 Å (E_exc = 0) line, but inadequite in all other
investigated cases.
---------------------------------------------------------
Title: Solar carbon monoxide: poster child for 3D effects .
Authors: Ayres, T. R.; Lyons, J. R.; Ludwig, H. -G.; Caffau, E.;
Wedemeyer-Böhm, S.
2013MSAIS..24...85A Altcode:
Photospheric infrared (2-6 mu m) rovibrational bands of carbon
monoxide (CO) provide a tough test for 3D convection models such as
those calculated using CO5BOLD. The molecular formation is highly
temperature-sensitive, and thus responds in an exaggerated way to
thermal fluctuations in the dynamic atmosphere. CO, itself, is an
important tracer of the oxygen abundance, a still controversial
issue in solar physics; as well as the heavy isotopes of carbon
(<SUP>13</SUP>C) and oxygen (<SUP>18</SUP>O, <SUP>17</SUP>O), which,
relative to terrestrial values, are fingerprints of fractionation
processes that operated in the primitive solar nebula. We show how 3D
models impact the CO line formation, and add in a second constraint
involving the near-UV Ca RIPTSIZE II line wings, which also are highly
temperature sensitive, but in the opposite sense to the molecules. We
find that our reference CO5BOLD snapshots appear to be slightly too
cool on average in the outer layers of the photosphere where the CO
absorptions and Ca RIPTSIZE II wing emissions arise. We show, further,
that previous 1D modeling was systematically biased toward higher
oxygen abundances and lower isotopic ratios (e.g., R<SUB>23</SUB>equiv
<SUP>12</SUP>C/<SUP>13</SUP>C), suggesting an isotopically “heavy”
Sun contrary to direct capture measurements of solar wind light ions
by the Genesis Discovery Mission. New 3D ratios for the oxygen isotopes
are much closer to those reported by Genesis, and the associated oxygen
abundance from CO now is consistent with the recent Caffau et al. study
of atomic oxygen. Some lingering discrepancies perhaps can be explained
by magnetic bright points. Solar CO demonstrates graphically the wide
gulf that can occur between a 3D analysis and 1D.
---------------------------------------------------------
Title: Oxygen spectral line synthesis: 3D non-LTE with
CO<SUP>5</SUP>BOLD hydrodynamical model atmospheres.
Authors: Prakapavičius, D.; Steffen, M.; Kučinskas, A.; Ludwig,
H. -G.; Freytag, B.; Caffau, E.; Cayrel, R.
2013MSAIS..24..111P Altcode: 2013arXiv1303.2016P
In this work we present first results of our current project aimed at
combining the 3D hydrodynamical stellar atmosphere approach with non-LTE
(NLTE) spectral line synthesis for a number of key chemical species. We
carried out a full 3D-NLTE spectrum synthesis of the oxygen IR 777 nm
triplet, using a modified and improved version of our NLTE3D package to
calculate departure coefficients for the atomic levels of oxygen in a
CO<SUP>5</SUP>BOLD 3D hydrodynamical solar model atmosphere. Spectral
line synthesis was subsequently performed with the Linfor3D code. In
agreement with previous studies, we find that the lines of the
oxygen triplet produce deeper cores under NLTE conditions, due to
the diminished line source function in the line forming region. This
means that the solar oxygen IR 777 nm lines should be stronger in NLTE,
leading to negative 3D NLTE-LTE abundance corrections. Qualitatively
this result would support previous claims for a relatively low solar
oxygen abundance. Finally, we outline several further steps that need
to be taken in order to improve the physical realism and numerical
accuracy of our current 3D-NLTE calculations.
---------------------------------------------------------
Title: r-process abundances in the EMP star CS 31082-001 using
STIS/HST
Authors: Siqueira-Mello, C., Jr.; Spite, M.; Barbuy, B.; Spite, F.;
Caffau, E.; Hill, V.; Wanajo, S.; Primas, F.; Plez, B.; Cayrel, R.;
Andersen, J.; Nordström, B.; Sneden, C.; Beers, T. C.; Bonifacio,
P.; François, P.; Molaro, P.
2012sf2a.conf..129S Altcode:
We present a brief revision of the origin of heavy elements and the role
of abundances in extremely metal-poor (EMP) stars, in providing improved
constraints on the nature of the early nucleosynthesis mechanisms. Heavy
element abundances in the EMP uranium-rich star CS 31082-001 based
mainly on near-UV spectra from STIS/HST are presented. With new
abundances for 9 n-elements not available in previous works (Ge, Mo,
Lu, Ta, W, Re, Pt, Au, and Bi) this work makes CS 31082-001 the most
completely well studied r-II object, with a total of 37 detections
of n-capture elements. These results should be useful for a better
characterisation of the neutron exposure(s) that produced the r-process
elements in this star, as well as a guide for improving nuclear data
and astrophysical site modelling.
---------------------------------------------------------
Title: Constraining the Milky Way thick disk formation: Chemical
characterization of the thick disk outside of the solar neighbourhood
Authors: Posbic, H.; Katz, D.; Haywood, M.; Bonifacio, P.; Caffau,
E.; Gomez, A.; Sbordone, L.; Arenou, F.; Royer, F.
2012sf2a.conf..103P Altcode:
The formation of the Milky Way disk is still an open question. Many
scenarios are proposed. Different formation scenarios predict different
disk chemical trends. This work aims to chemically characterize
the Milky Way disk inside and outside the solar neighbourhood, to
better constrain its formation scenario. This is possible thanks to
high resolution spectra of 200 disk stars observed using the Giraffe
spectrograph on the Very Large Telescope (VLT). They were selected to
have galactic altitudes |Z| that cover both the thin and thick disk
(|Z| up to 2 kpc). The new automatic spectra analysis software SPADES
(Stellar PArameters DEtermination Software, Posbic et al. 2012) was
used to determine the stellar parameters, and most importantly, the
elemental abundances of these stars. The distances of these stars were
also determined. The metallicity distribution function of the disk
using this sample was calculated. It showed a large contribution of
the thick disk stars and a smooth transition at the metallicity of the
thick disk/halo interface. The vertical behaviour of the metallicity
distribution function was also studied. A vertical metallicity gradient
in the disk of partial [Fe/H] / partial |Z| = -0.19 ± 0.14 dex/kpc was
marginally detected at the 1.4 sigma level. The [Ti/Fe] and [Ca/Fe]
vs [Fe/H] trends for the stars are determined. The main result of
the analysis is that the trends of [Ca/Fe] vs [Fe/H] and [Ti/Fe] vs
[Fe/H] show no significant difference close (i.e. |Z| leq 1 kpc) and
farther away (1 < |Z| < 2.5 kpc) from the Galactic plane. This
suggests that thick disk gas and stars have been enriched by the same
proportion of type II and type I super-novae from the galactic plane
up to at least 2.5 kpc. These results support thick disk formation
scenarios like collapse or gas-rich accretion and disfavour a thick
disk formed of stars captured during a merger event.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Model 1D (LHD) and 3D (CO5BOLD)
spectra (Allende Prieto+, 2013)
Authors: Allende Prieto, C.; Koesterke, L. Ludwig H. -G.; Freytag,
B.; Caffau, E.
2012yCat..35500103A Altcode: 2012yCat..35509103A
Model spectral fluxes for late-type stars computed from 3D
hydrodynamical simulations of surface convection performed with the
CO5BOLD code. Their 1D hydrostatic counterparts are included, based on
the LHD code, sharing the same microphysics as the CO5BOLD models. The
fluxes for both the 3D and 1D models are calculated with the same
opacities and radiative transfer code (ASSET). <P />(6 data files).
---------------------------------------------------------
Title: 4MOST: 4-metre multi-object spectroscopic telescope
Authors: de Jong, Roelof S.; Bellido-Tirado, Olga; Chiappini,
Cristina; Depagne, Éric; Haynes, Roger; Johl, Diana; Schnurr,
Olivier; Schwope, Axel; Walcher, Jakob; Dionies, Frank; Haynes,
Dionne; Kelz, Andreas; Kitaura, Francisco S.; Lamer, Georg; Minchev,
Ivan; Müller, Volker; Nuza, Sebastián. E.; Olaya, Jean-Christophe;
Piffl, Tilmann; Popow, Emil; Steinmetz, Matthias; Ural, Ugur; Williams,
Mary; Winkler, Roland; Wisotzki, Lutz; Ansorge, Wolfgang R.; Banerji,
Manda; Gonzalez Solares, Eduardo; Irwin, Mike; Kennicutt, Robert C.;
King, Dave; McMahon, Richard G.; Koposov, Sergey; Parry, Ian R.; Sun,
David; Walton, Nicholas A.; Finger, Gert; Iwert, Olaf; Krumpe, Mirko;
Lizon, Jean-Louis; Vincenzo, Mainieri; Amans, Jean-Philippe; Bonifacio,
Piercarlo; Cohen, Mathieu; Francois, Patrick; Jagourel, Pascal; Mignot,
Shan B.; Royer, Frédéric; Sartoretti, Paola; Bender, Ralf; Grupp,
Frank; Hess, Hans-Joachim; Lang-Bardl, Florian; Muschielok, Bernard;
Böhringer, Hans; Boller, Thomas; Bongiorno, Angela; Brusa, Marcella;
Dwelly, Tom; Merloni, Andrea; Nandra, Kirpal; Salvato, Mara; Pragt,
Johannes H.; Navarro, Ramón; Gerlofsma, Gerrit; Roelfsema, Ronald;
Dalton, Gavin B.; Middleton, Kevin F.; Tosh, Ian A.; Boeche, Corrado;
Caffau, Elisabetta; Christlieb, Norbert; Grebel, Eva K.; Hansen,
Camilla; Koch, Andreas; Ludwig, Hans-G.; Quirrenbach, Andreas;
Sbordone, Luca; Seifert, Walter; Thimm, Guido; Trifonov, Trifon;
Helmi, Amina; Trager, Scott C.; Feltzing, Sofia; Korn, Andreas;
Boland, Wilfried
2012SPIE.8446E..0TD Altcode: 2012arXiv1206.6885D
The 4MOST consortium is currently halfway through a Conceptual
Design study for ESO with the aim to develop a wide-field ( <
3 square degree, goal < 5 square degree), high-multiplex ( <
1500 fibres, goal 3000 fibres) spectroscopic survey facility for
an ESO 4m-class telescope (VISTA). 4MOST will run permanently on
the telescope to perform a 5 year public survey yielding more than
20 million spectra at resolution R∼5000 (λ=390-1000 nm) and more
than 2 million spectra at R~20,000 (395-456.5 nm and 587-673 nm). The
4MOST design is especially intended to complement three key all-sky,
space-based observatories of prime European interest: Gaia, eROSITA and
Euclid. Initial design and performance estimates for the wide-field
corrector concepts are presented. Two fibre positioner concepts are
being considered for 4MOST. The first one is a Phi-Theta system similar
to ones used on existing and planned facilities. The second one is a
new R-Theta concept with large patrol area. Both positioner concepts
effectively address the issues of fibre focus and pupil pointing. The
4MOST spectrographs are fixed configuration two-arm spectrographs,
with dedicated spectrographs for the high- and low-resolution fibres. A
full facility simulator is being developed to guide trade-off decisions
regarding the optimal field-of-view, number of fibres needed, and the
relative fraction of high-to-low resolution fibres. The simulator takes
mock catalogues with template spectra from Design Reference Surveys
as starting point, calculates the output spectra based on a throughput
simulator, assigns targets to fibres based on the capabilities of the
fibre positioner designs, and calculates the required survey time by
tiling the fields on the sky. The 4MOST consortium aims to deliver the
full 4MOST facility by the end of 2018 and start delivering high-level
data products for both consortium and ESO community targets a year
later with yearly increments.
---------------------------------------------------------
Title: 4MOST spectral data simulation
Authors: Sartoretti, Paola; Leclerc, Nicolas; Walcher, Jakob; Caffau,
Elisabetta; Sbordone, Luca; Laporte, Philippe
2012SPIE.8446E..5PS Altcode:
4MOST is a phase A study of a very high-multiplex, wide-field fibre-fed
spectrograph system for the VISTA or NTT telescope. The main stellar
goal of the instrument is to complement and complete the informations
on the Milky Way, that Gaia will provide both on radial velocity and
chemical analysis. Two resolution modes (about 5000 and 20000) are
foreseen to operate at the same time. We have developed a simulator
of spectral data for the 4MOST spectrograph. This simulator produces
mock scientic spectra to be analyzed by the science team in order to
constrain the feasibility of their requirements and help refine the
high-level specications of the instrument. We present here the spectra
simulator and how some of the simulation results are used to define
the performances of 4MOST.
---------------------------------------------------------
Title: Detailed abundances in EMP dwarfs from SDSS
Authors: Sbordone, Luca; Caffau, Elisabetta; Bonifacio, Piercarlo
2012AIPC.1480..160S Altcode:
We report on the current status of an ongoing survey to select extremely
metal poor (EMP) turn-off (TO) stars from Sloan Digital Sky Survey
(SDSS) spectra, and determine their detailed chemical composition
through high resolution follow-up. So far, 26 stars have been observed
with UVESatVLT and X-SHOOTERatVLT, all but two showing an iron content
below [Fe/H]=-3. Among them we detected the current record holder for
the lowest total metallicity (SDSS J102915+172927, Z=10-5 Zsolar),
four carbon-enhanced extremely metal poor objects (CEMP), as well
as subsets with enhanced Ni and Mn. Lithium abundances or upper
limits were derived, confirming the previously detected “meltdown”
of the Spite plateau for metallicities below about [Fe/H]=-2.8. SDSS
J102915+172927 in particular shows no detectable Li I 670.8 doublet,
leading to an upper limit of A(Li)<1.1, hinting to an even deeper
Li depletion in TO stars below [Fe/H]=-4. Spectroscopic follow-up is
currently being prosecuted by the recently started ESO large program
TOPoS, aiming to observe about 80 more EMP candidates.
---------------------------------------------------------
Title: SPADES: Stellar Parameters Determination Software
Authors: Posbic, Helene; Katz, David; Caffau, Elisabetta; Bonifacio,
Piercarlo; Gomez, Ana; Sbordone, Luca; Arenou, Frederic
2012arXiv1209.0407P Altcode:
Context. As increasingly more spectroscopic data are being delivered
by medium- and high-resolving power multi-object spectrographs,
more automatic stellar parameter determination softwares are
being developed. The quality of the spectra collected also allows
the determination of elemental abundances. Aims. SPADES is an
automated software for determining: the radial velocity (Vr),
the effective temperature (Teff), the surface gravity (log g),
the metallicity ([Fe/H]), and most importantly, the individual
abundances. In this first version it is targeted on the analysis of
mid-F-G dwarfs, but is meant to evolve to analyze any type of single
stars. Methods. SPADES relies on a line-by-line modeling to determine
the stellar parameters. Results. The internal systematic and random
errors of SPADES were assessed by Monte Carlo method simulations with
synthetic spectra and the external systematic errors by analysing real
ground-based observed spectra. For example, by simulating the Giraffe
setups HR13 and HR14B with synthetic spectra for a dwarf with Teff =
5800 K, log g = 4.5, [Fe/H] = 0.0 dex and with a signal-tonoise ratio
(S/N) of 100, the stellar parameters are recovered with no significant
bias and with 1-{\sigma} precisions of 8 K for Teff, 0.05 for log g,
0.009 for [Fe/H], 0.003 for [Ti/Fe] and 0.01 for [Ni/Fe].
---------------------------------------------------------
Title: An upper limit on the sulphur abundance in HE 1327-2326
Authors: Bonifacio, P.; Caffau, E.; Venn, K. A.; Lambert, D. L.
2012A&A...544A.102B Altcode: 2012arXiv1207.1806B
Context. Star HE 1327-2326 is a unique object, with the lowest measured
iron abundance ([Fe/H] ~ -6) and a peculiar chemical composition that
includes large overabundances of C, N, and O with respect to iron. One
important question is whether the chemical abundances in this star
reflect the chemical composition of the gas cloud from which it was
formed or if they have been severely affected by other processes,
such as dust-gas winnowing. <BR /> Aims: We measure or provide an
upper limit to the abundance of the volatile element sulphur, which
can help to discriminate between the two scenarios. <BR /> Methods: We
observed HE 1327-2326 with the high resolution infra-red spectrograph
CRIRES at the VLT to observe the S i lines of Multiplet 3 at 1045
nm. <BR /> Results: We do not detect the S i line. A 3σ upper limit
on the equivalent width (EW) of any line in our spectrum is EW <
0.66 pm. Using either one-dimensional static or three-dimensional
hydrodynamical model-atmospheres, this translates into a robust upper
limit of [S/H] < -2.6. <BR /> Conclusions: This upper limit does
not provide conclusive evidence for or against dust-gas winnowing,
and the evidence coming from other elements (e.g., Na and Ti) is
also inconclusive or contradictory. The formation of dust in the
atmosphere versus an origin of the metals in a metal-poor supernova
with extensive "fall-back" are not mutually exclusive. It is possible
that dust formation distorts the peculiar abundance pattern created by a
supernova with fall-back, thus the abundance ratios in HE 1327-2326 may
be used to constrain the properties of the supernova(e) that produced
its metals, but with some caution. <P />Based on spectra obtained with
CRIRES at the 8.2 m Antu ESO telescope, programme 386.D-0095.
---------------------------------------------------------
Title: SPADES: a stellar parameters determination software
Authors: Posbic, H.; Katz, D.; Caffau, E.; Bonifacio, P.; Gómez,
A.; Sbordone, L.; Arenou, F.
2012A&A...544A.154P Altcode: 2011arXiv1111.0474P
Context. As increasingly more spectroscopic data are being delivered
by medium- and high-resolving power multi-object spectrographs,
more automatic stellar parameter determination softwares are being
developed. The quality of the spectra collected also allows the
determination of elemental abundances. <BR /> Aims: SPADES is an
automated software for determining: the radial velocity (V<SUB>r</SUB>),
the effective temperature (T<SUB>eff</SUB>), the surface gravity (log
g), the metallicity ( [Fe/H] ), and most importantly, the individual
abundances. In this first version it is targeted on the analysis of
mid-F-G dwarfs, but is meant to evolve to analyze any type of single
stars. <BR /> Methods: SPADES relies on a line-by-line modeling
to determine the stellar parameters. <BR /> Results: The internal
systematic and random errors of SPADES were assessed by Monte Carlo
method simulations with synthetic spectra and the external systematic
errors by analysing real ground-based observed spectra. For example,
by simulating the Giraffe setups HR13 and HR14B with synthetic spectra
for a dwarf with K, , dex and with a signal-to-noise ratio (S/N) of
100, the stellar parameters are recovered with no significant bias
and with 1-σ precisions of 8 K for T<SUB>eff</SUB>, 0.05 for log g,
0.009 for [Fe/H] , 0.003 for [Ti/Fe] and 0.01 for [Ni/Fe] .
---------------------------------------------------------
Title: Detailed Abundances in Extremely Metal Poor Dwarf Stars
Extracted from SDSS
Authors: Sbordone, L.; Bonifacio, P.; Caffau, E.; Ludwig, H. -G.
2012ASPC..458...69S Altcode: 2012arXiv1201.1044S
We report on the result of an ongoing campaign to determine chemical
abundances in extremely metal poor (EMP) turn-off (TO) stars selected
from the Sloan Digital Sky Survey (SDSS) low resolution spectra. This
contribution focuses principally on the largest part of the sample
(18 stars out of 29), observed with UVES@VLT and analyzed by means of
the automatic abundance analysis code MyGIsFOS to derive atmosphere
parameters and detailed compositions. The most significant findings
include i) the detection of a C-rich, strongly Mg-enhanced star
([Mg/Fe]=1.45); ii) a group of Mn-rich stars ([Mn/Fe]>-0.4); iii)
a group of Ni-rich stars ([Ni/Fe]>0.2). Li is measured in twelve
stars, while for three upper limits are derived.
---------------------------------------------------------
Title: Amplitudes of solar-like oscillations in red giant
stars. Evidence for non-adiabatic effects using CoRoT observations
Authors: Samadi, R.; Belkacem, K.; Dupret, M. -A.; Ludwig, H. -G.;
Baudin, F.; Caffau, E.; Goupil, M. -J.; Barban, C.
2012A&A...543A.120S Altcode: 2012arXiv1205.4846S
Context. A growing number of solar-like oscillations has been detected
in red giant stars thanks to the CoRoT and Kepler space-crafts. In
the same way as for main-sequence stars, mode driving is attributed
to turbulent convection in the uppermost convective layers of those
stars. <BR /> Aims: The seismic data gathered by CoRoT on red giant
stars allow us to test the mode driving theory in physical conditions
different from main-sequence stars. <BR /> Methods: Using a set of
3D hydrodynamical models representative of the upper layers of sub-
and red giant stars, we computed the acoustic mode energy supply rate
({p_max}). Assuming adiabatic pulsations and using global stellar
models that assume that the surface stratification comes from the
3D hydrodynamical models, we computed the mode amplitude in terms
of surface velocity. This was converted into intensity fluctuations
using either a simplified adiabatic scaling relation or a non-adiabatic
one. <BR /> Results: From L and M (the luminosity and mass), the energy
supply rate {p_max} is found to scale as (L/M)<SUP>2.6</SUP> for both
main-sequence and red giant stars, extending previous results. The
theoretical amplitudes in velocity under-estimate the Doppler velocity
measurements obtained so far from the ground for red giant stars by
about 30%. In terms of intensity, the theoretical scaling law based
on the adiabatic intensity-velocity scaling relation results in an
under-estimation by a factor of about 2.5 with respect to the CoRoT
seismic measurements. On the other hand, using the non-adiabatic
intensity-velocity relation significantly reduces the discrepancy with
the CoRoT data. The theoretical amplitudes remain 40% below, however,
the CoRoT measurements. <BR /> Conclusions: Our results show that
scaling relations of mode amplitudes cannot be simply extended from
main-sequence to red giant stars in terms of intensity on the basis of
adiabatic relations because non-adiabatic effects for red giant stars
are important and cannot be neglected. We discuss possible reasons
for the remaining differences.
---------------------------------------------------------
Title: Chemical abundances of distant extremely metal-poor unevolved
stars
Authors: Bonifacio, P.; Sbordone, L.; Caffau, E.; Ludwig, H. -G.;
Spite, M.; González Hernández, J. I.; Behara, N. T.
2012A&A...542A..87B Altcode: 2012arXiv1204.1641B
Context. The old Galactic halo stars hold the fossil record of
the interstellar medium chemical composition at the time of their
formation. Most of the stars studied so far are relatively near to the
Sun, this prompts the study of more distant stars, both to increase the
size of the sample and to search for possible variations of abundance
patterns at greater distances. <BR /> Aims: The purpose of our study
is to determine the chemical composition of a sample of 16 candidate
extremely metal-poor (EMP) dwarf stars, extracted from the Sloan
Digital Sky Survey (SDSS). There are two main purposes: in the first
place to verify the reliability of the metallicity estimates derived
from the SDSS spectra; in the second place to see if the abundance
trends found for the brighter nearer stars studied previously also
hold for this sample of fainter, more distant stars. <BR /> Methods:
We used the UVES at the VLT to obtain high-resolution spectra of the
programme stars. The abundances were determined by an automatic analysis
with the MyGIsFOS code, with the exception of lithium, for which the
abundances were determined from the measured equivalent widths of the
Li i resonance doublet. <BR /> Results: All candidates are confirmed
to be EMP stars, with [Fe/H] ≤ -3.0. The chemical composition of the
sample of stars is similar to that of brighter and nearer samples. We
measured the lithium abundance for 12 stars and provide stringent upper
limits for three other stars, for a fourth star the upper limit is not
significant, owing to the low signal-to noise ratio of the spectrum. The
"meltdown" of the Spite plateau is confirmed, but some of the lowest
metallicity stars of the sample lie on the plateau. <BR /> Conclusions:
The concordance of the metallicities derived from high-resolution
spectra and those estimated from the SDSS spectra suggests that
the latter may be used to study the metallicity distribution of the
halo. The abundance pattern suggests that the halo was well mixed for
all probed metallicities and distances. The fact that at the lowest
metallicities we find stars on the Spite plateau suggests that the
meltdown depends on at least another parameter, besides metallicity. <P
/>Based on spectra obtained with UVES at the 8.2 m Kueyen ESO telescope,
programmes 078.D-0217 and 081.D.0373.Table 1 is available in electronic
form at <A href="http://www.aanda.org">http://www.aanda.org</A>
---------------------------------------------------------
Title: A primordial star in the heart of the Lion
Authors: Caffau, E.; Bonifacio, P.; François, P.; Spite, M.; Spite,
F.; Zaggia, S.; Ludwig, H. -G.; Steffen, M.; Mashonkina, L.; Monaco,
L.; Sbordone, L.; Molaro, P.; Cayrel, R.; Plez, B.; Hill, V.; Hammer,
F.; Randich, S.
2012A&A...542A..51C Altcode: 2012arXiv1203.2607C
Context. The discovery and chemical analysis of extremely metal-poor
stars permit a better understanding of the star formation of the first
generation of stars and of the Universe emerging from the Big Bang. <BR
/> Aims: We report the study of a primordial star situated in the centre
of the constellation Leo (SDSS J102915+172927). <BR /> Methods: The
star, selected from the low-resolution spectrum of the Sloan Digital
Sky Survey, was observed at intermediate (with X-Shooter at VLT) and
at high spectral resolution (with UVES at VLT). The stellar parameters
were derived from the photometry. The standard spectroscopic analysis
based on 1D ATLAS models was completed by applying 3D and non-LTE
corrections. <BR /> Results: An iron abundance of [Fe/H ] = -4.89 makes
SDSS J102915+172927 one of the lowest [Fe/H] stars known. However,
the absence of measurable C and N enhancements indicates that it has
the lowest metallicity, Z ≤ 7.40 × 10<SUP>-7</SUP> (metal-mass
fraction), ever detected. No oxygen measurement was possible. <BR />
Conclusions: The discovery of SDSS J102915+172927 highlights that
low-mass star formation occurred at metallicities lower than previously
assumed. Even lower metallicity stars may yet be discovered, with a
chemical composition closer to the composition of the primordial gas
and of the first supernovae. <P />Based on observations obtained at ESO
Paranal Observatory, GTO programme 086.D-0094 and programme 286.D-5045.
---------------------------------------------------------
Title: NLTE determination of the calcium abundance and 3D corrections
in extremely metal-poor stars
Authors: Spite, M.; Andrievsky, S. M.; Spite, F.; Caffau, E.; Korotin,
S. A.; Bonifacio, P.; Ludwig, H. -G.; François, P.; Cayrel, R.
2012A&A...541A.143S Altcode: 2012arXiv1204.1139S
Context. Calcium is a key element for constraining the models of
chemical enrichment of the Galaxy. <BR /> Aims: Extremely metal-poor
stars contain the fossil records of the chemical composition of the
early Galaxy and it is important to compare Ca abundance with abundances
of other light elements, that are supposed to be synthesized in the
same stellar evolution phases. <BR /> Methods: The NLTE profiles of the
calcium lines were computed in a sample of 53 extremely metal-poor stars
with a modified version of the program MULTI, which allows a very good
description of the radiation field. <BR /> Results: With our new model
atom we are able to reconcile the abundance of Ca deduced from the Ca
I and Ca II lines in Procyon. This abundance is found to be solar. We
find that [Ca/Fe] = 0.50±0.09 in the early Galaxy, a value slightly
higher than the previous LTE estimations. The scatter of the ratios
[X/Ca] is generally smaller than the scatter of the ratio [X/Mg] where
X is a "light metal" (O, Na, Mg, Al, S, and K) with the exception of
Al. These scatters cannot be explained by error of measurements, except
for oxygen. Surprisingly, the scatter of [X/Fe] is always equal to, or
even smaller than, the scatter around the mean value of [X/Ca]. We note
that at low metallicity, the wavelength of the Ca I resonance line is
shifted relative to the (weaker) subordinate lines, a signature of the
effect of convection. The Ca abundance deduced from the Ca I resonance
line (422.7 nm) is found to be systematically smaller at very low
metallicity than the abundance deduced from the subordinate lines. Our
computations of the effects of convection (3D effects) are not able to
explain this difference. A fully consistent 3D NLTE model atmosphere
and line formation scheme would be necessary to fully capture the
physics of the stellar atmosphere. <P />Based on observations obtained
with the ESO Very Large Telescope at Paranal Observatory, Chile (Large
Programme "First Stars", ID 165.N-0276(A); P.I.: R. Cayrel).The NLTE
corrections of the Ca lines are available in electronic form at the
CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/541/A143">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/541/A143</A>
---------------------------------------------------------
Title: VizieR Online Data Catalog: Li and Na in globular cluster M4
(Monaco+, 2012)
Authors: Monaco, L.; Villanova, S.; Bonifacio, P.; Caffau, E.; Geisler,
D.; Marconi, G.; Momany, Y.; Ludwig, H. -G.
2012yCat..35390157M Altcode: 2012yCat..35399157M
We observed stars along the M4 MS and SGB using the FLAMES/GIRAFFE
spectrograph at ESO Paranal. Observations were conducted in service
mode between April and July 2010 using the HR12 and HR15N settings. <P
/>(1 data file).
---------------------------------------------------------
Title: Barium abundance in red giants of NGC 6752. Non-local
thermodynamic equilibrium and three-dimensional effects
Authors: Dobrovolskas, V.; Kučinskas, A.; Andrievsky, S. M.; Korotin,
S. A.; Mishenina, T. V.; Bonifacio, P.; Ludwig, H. -G.; Caffau, E.
2012A&A...540A.128D Altcode: 2012arXiv1203.3124D
<BR /> Aims: We study the effects related to departures from non-local
thermodynamic equilibrium (NLTE) and homogeneity in the atmospheres
of red giant stars, to assess their influence on the formation of
Ba II lines. We estimate the impact of these effects on the barium
abundance determinations for 20 red giants in Galactic globular cluster
NGC 6752. <BR /> Methods: One-dimensional (1D) local thermodynamic
equilibrium (LTE) and 1D NLTE barium abundances were derived using
classical 1D ATLAS9 stellar model atmospheres. The three-dimensional
(3D) LTE abundances were obtained for 8 red giants on the lower RGB,
by adjusting their 1D LTE abundances using 3D-1D abundance corrections,
i.e., the differences between the abundances obtained from the same
spectral line using the 3D hydrodynamical and classical 1D stellar
model atmospheres. The 3D-1D abundance corrections were obtained
in a strictly differential way using the 3D hydrodynamical and
classical 1D codes CO<SUP>5</SUP>BOLD and LHD. Both codes utilized
identical stellar atmospheric parameters, opacities, and equation
of state. <BR /> Results: The mean 1D barium-to-iron abundance
ratios derived for 20 giants are ⟨[Ba/Fe]⟩<SUB>1D LTE</SUB> =
0.24 ± 0.05(stat.) ± 0.08(sys.) and ⟨[Ba/Fe]⟩<SUB>1D NLTE</SUB>
= 0.05 ± 0.06(stat.) ± 0.08(sys.). The 3D-1D abundance correction
obtained for 8 giants is small (~+0.05 dex), thus leads to only minor
adjustment when applied to the mean 1D NLTE barium-to-iron abundance
ratio for the 20 giants, ⟨[Ba/Fe]⟩<SUB>3D + NLTE</SUB> = 0.10
± 0.06(stat.) ± 0.10(sys.). The intrinsic abundance spread between
the individual cluster stars is small and can be explained in terms
of uncertainties in the abundance determinations. <BR /> Conclusions:
Deviations from LTE play an important role in the formation of barium
lines in the atmospheres of red giants studied here. The role of
3D hydrodynamical effects should not be dismissed either, even if
the obtained 3D-1D abundance corrections are small. This result is
a consequence of subtle fine-tuning of individual contributions from
horizontal temperature fluctuations and differences between the average
temperature profiles in the 3D and 1D model atmospheres: owing to the
comparable size and opposite sign, their contributions nearly cancel
each other. This fine-tuning is characteristic of the particular set
of atmospheric parameters and the element investigated, hence should
not necessarily be a general property of spectral line formation in
the atmospheres of red giant stars.
---------------------------------------------------------
Title: Chemical evolution of the Milky Way: the origin of phosphorus
Authors: Cescutti, G.; Matteucci, F.; Caffau, E.; François, P.
2012A&A...540A..33C Altcode: 2011arXiv1112.3824C
Context. Recently, the abundance of P was measured for the first
time in disk stars. This provides the opportunity of comparing the
observed abundances with predictions from theoretical models. <BR />
Aims: We aim at predicting the chemical evolution of P in the Milky
Way and compare our results with the observed P abundances in disk
stars to derive constraints on the P nucleosynthesis. <BR /> Methods:
We adopted the two-infall model of galactic chemical evolution,
which is a good model for the Milky Way, and computed the evolution
of the abundances of P and Fe. We adopted stellar yields for these
elements from different sources. The element P is expected to form
mainly in type-II supernovae, whereas Fe is mainly produced by type-Ia
supernovae. <BR /> Results: Our results confirm that to reproduce the
observed trend of [P/Fe] vs. [Fe/H] in disk stars, P must be formed
mainly in massive stars. However, none of the available yields for
P can reproduce the solar abundance of this element. In other words,
to reproduce the data one needs to assume that massive stars produce
three times more P than predicted. <BR /> Conclusions: We conclude
that the entire available yields of P from massive stars are largely
underestimated and that nucleosynthesis calculations should be
revised. We also predict the [P/Fe] expected in halo stars.
---------------------------------------------------------
Title: LTE Model Atmospheres: MARCS, ATLAS and CO5BOLD
Authors: Bonifacio, P.; Caffau, E.; Ludwig, H. -G.; Steffen, M.
2012IAUS..282..213B Altcode:
In this talk, we review the basic assumptions and physics covered
by classical 1D LTE model atmospheres. We will focus on ATLAS and
MARCS models of F-G-K stars and describe what resources are available
through the web, both in terms of codes and model-atmosphere grids. We
describe the advances made in hydrodynamical simulations of convective
stellar atmospheres with the CO<SUP>5</SUP>BOLD code and what grids
and resources are available, with a prospect of what will be available
in the near future.
---------------------------------------------------------
Title: Planetary companions around the metal-poor star HIP 11952
Authors: Setiawan, J.; Roccatagliata, V.; Fedele, D.; Henning, Th.;
Pasquali, A.; Rodríguez-Ledesma, M. V.; Caffau, E.; Seemann, U.;
Klement, R. J.
2012A&A...540A.141S Altcode: 2012arXiv1208.4000S
<BR /> Aims: We carried out a radial-velocity survey to search for
planets around metal-poor stars. In this paper we report the discovery
of two planets around HIP 11952, a metal-poor star with [Fe/H] = -1.9
that belongs to our target sample. <BR /> Methods: Radial velocity
variations of HIP 11952 were monitored systematically with FEROS
at the 2.2 m telescope located at the ESO La Silla observatory from
August 2009 until January 2011. We used a cross-correlation technique
to measure the stellar radial velocities (RV). <BR /> Results:
We detected a long-period RV variation of 290 d and a short-period
one of 6.95 d. The spectroscopic analysis of the stellar activity
reveals a stellar rotation period of 4.8 d. The Hipparcos photometry
data shows intra-day variabilities, which give evidence for stellar
pulsations. Based on our analysis, the observed RV variations are most
likely caused by the presence of unseen planetary companions. Assuming
a primary mass of 0.83 M<SUB>⊙</SUB>, we computed minimum planetary
masses of 0.78 M<SUB>Jup</SUB> for the inner and 2.93 M<SUB>Jup</SUB>
for the outer planet. The semi-major axes are a<SUB>1</SUB> = 0.07
AU and a<SUB>2</SUB> = 0.81 AU, respectively. <BR /> Conclusions:
HIP 11952 is one of very few stars with [Fe/H] < -1.0 which have
planetary companions. This discovery is important to understand planet
formation around metal-poor stars.
---------------------------------------------------------
Title: VizieR Online Data Catalog: NLTE Corrections of the Ca lines
(Spite+, 2012)
Authors: Spite, M.; Andrievsky, S. M.; Spite, F.; Caffau, E.; Korotin,
S. A.; Bonifacio, P.; Ludwig, H. -G.; Francois, P.; Cayrel, R.
2012yCat..35410143S Altcode: 2012yCat..35419143S
The NLTE corrections were computed for 51 CaI lines and 16 CaII lines
for a grid of models with different metallicities from [Fe/H]=0.0
to [Fe/H]=-3. These corrections must be added to the LTE value of
[Ca/H], they were computed only if the equivalent width of the Ca line
was stronger than 3mÅ. In the tables the model is given in the form
(Teff, logg, [Fe/H], [Ca/Fe]) where Teff is the effective temperature,
and logg the logarithm of the surface gravity) <P />(5 data files).
---------------------------------------------------------
Title: The Gaia-ESO Public Spectroscopic Survey
Authors: Gilmore, G.; Randich, S.; Asplund, M.; Binney, J.; Bonifacio,
P.; Drew, J.; Feltzing, S.; Ferguson, A.; Jeffries, R.; Micela, G.;
Negueruela, I.; Prusti, T.; Rix, H. -W.; Vallenari, A.; Alfaro, E.;
Allende-Prieto, C.; Babusiaux, C.; Bensby, T.; Blomme, R.; Bragaglia,
A.; Flaccomio, E.; François, P.; Irwin, M.; Koposov, S.; Korn, A.;
Lanzafame, A.; Pancino, E.; Paunzen, E.; Recio-Blanco, A.; Sacco,
G.; Smiljanic, R.; Van Eck, S.; Walton, N.; Aden, D.; Aerts, C.;
Affer, L.; Alcala, J. -M.; Altavilla, G.; Alves, J.; Antoja, T.;
Arenou, F.; Argiroffi, C.; Asensio Ramos, A.; Bailer-Jones, C.;
Balaguer-Nunez, L.; Bayo, A.; Barbuy, B.; Barisevicius, G.; Barrado
y Navascues, D.; Battistini, C.; Bellas Velidis, I.; Bellazzini, M.;
Belokurov, V.; Bergemann, M.; Bertelli, G.; Biazzo, K.; Bienayme, O.;
Bland-Hawthorn, J.; Boeche, C.; Bonito, S.; Boudreault, S.; Bouvier,
J.; Brandao, I.; Brown, A.; de Bruijne, J.; Burleigh, M.; Caballero,
J.; Caffau, E.; Calura, F.; Capuzzo-Dolcetta, R.; Caramazza, M.;
Carraro, G.; Casagrande, L.; Casewell, S.; Chapman, S.; Chiappini,
C.; Chorniy, Y.; Christlieb, N.; Cignoni, M.; Cocozza, G.; Colless,
M.; Collet, R.; Collins, M.; Correnti, M.; Covino, E.; Crnojevic,
D.; Cropper, M.; Cunha, M.; Damiani, F.; David, M.; Delgado, A.;
Duffau, S.; Edvardsson, B.; Eldridge, J.; Enke, H.; Eriksson, K.;
Evans, N. W.; Eyer, L.; Famaey, B.; Fellhauer, M.; Ferreras, I.;
Figueras, F.; Fiorentino, G.; Flynn, C.; Folha, D.; Franciosini,
E.; Frasca, A.; Freeman, K.; Fremat, Y.; Friel, E.; Gaensicke, B.;
Gameiro, J.; Garzon, F.; Geier, S.; Geisler, D.; Gerhard, O.; Gibson,
B.; Gomboc, A.; Gomez, A.; Gonzalez-Fernandez, C.; Gonzalez Hernandez,
J.; Gosset, E.; Grebel, E.; Greimel, R.; Groenewegen, M.; Grundahl,
F.; Guarcello, M.; Gustafsson, B.; Hadrava, P.; Hatzidimitriou, D.;
Hambly, N.; Hammersley, P.; Hansen, C.; Haywood, M.; Heber, U.; Heiter,
U.; Held, E.; Helmi, A.; Hensler, G.; Herrero, A.; Hill, V.; Hodgkin,
S.; Huelamo, N.; Huxor, A.; Ibata, R.; Jackson, R.; de Jong, R.;
Jonker, P.; Jordan, S.; Jordi, C.; Jorissen, A.; Katz, D.; Kawata,
D.; Keller, S.; Kharchenko, N.; Klement, R.; Klutsch, A.; Knude,
J.; Koch, A.; Kochukhov, O.; Kontizas, M.; Koubsky, P.; Lallement,
R.; de Laverny, P.; van Leeuwen, F.; Lemasle, B.; Lewis, G.; Lind,
K.; Lindstrom, H. P. E.; Lobel, A.; Lopez Santiago, J.; Lucas, P.;
Ludwig, H.; Lueftinger, T.; Magrini, L.; Maiz Apellaniz, J.; Maldonado,
J.; Marconi, G.; Marino, A.; Martayan, C.; Martinez-Valpuesta, I.;
Matijevic, G.; McMahon, R.; Messina, S.; Meyer, M.; Miglio, A.;
Mikolaitis, S.; Minchev, I.; Minniti, D.; Moitinho, A.; Momany, Y.;
Monaco, L.; Montalto, M.; Monteiro, M. J.; Monier, R.; Montes, D.;
Mora, A.; Moraux, E.; Morel, T.; Mowlavi, N.; Mucciarelli, A.; Munari,
U.; Napiwotzki, R.; Nardetto, N.; Naylor, T.; Naze, Y.; Nelemans, G.;
Okamoto, S.; Ortolani, S.; Pace, G.; Palla, F.; Palous, J.; Parker, R.;
Penarrubia, J.; Pillitteri, I.; Piotto, G.; Posbic, H.; Prisinzano,
L.; Puzeras, E.; Quirrenbach, A.; Ragaini, S.; Read, J.; Read, M.;
Reyle, C.; De Ridder, J.; Robichon, N.; Robin, A.; Roeser, S.; Romano,
D.; Royer, F.; Ruchti, G.; Ruzicka, A.; Ryan, S.; Ryde, N.; Santos,
N.; Sanz Forcada, J.; Sarro Baro, L. M.; Sbordone, L.; Schilbach, E.;
Schmeja, S.; Schnurr, O.; Schoenrich, R.; Scholz, R. -D.; Seabroke, G.;
Sharma, S.; De Silva, G.; Smith, M.; Solano, E.; Sordo, R.; Soubiran,
C.; Sousa, S.; Spagna, A.; Steffen, M.; Steinmetz, M.; Stelzer, B.;
Stempels, E.; Tabernero, H.; Tautvaisiene, G.; Thevenin, F.; Torra,
J.; Tosi, M.; Tolstoy, E.; Turon, C.; Walker, M.; Wambsganss, J.;
Worley, C.; Venn, K.; Vink, J.; Wyse, R.; Zaggia, S.; Zeilinger, W.;
Zoccali, M.; Zorec, J.; Zucker, D.; Zwitter, T.; Gaia-ESO Survey Team
2012Msngr.147...25G Altcode:
The Gaia-ESO Public Spectroscopic Survey has begun and will obtain high
quality spectroscopy of some 100000 Milky Way stars, in the field and
in open clusters, down to magnitude 19, systematically covering all the
major components of the Milky Way. This survey will provide the first
homogeneous overview of the distributions of kinematics and chemical
element abundances in the Galaxy. The motivation, organisation and
implementation of the Gaia-ESO Survey are described, emphasising the
complementarity with the ESA Gaia mission. Spectra from the very first
observing run of the survey are presented.
---------------------------------------------------------
Title: Lithium and sodium in the globular cluster <ASTROBJ>M
4</ASTROBJ>. Detection of a Li-rich dwarf star: preservation or
pollution?
Authors: Monaco, L.; Villanova, S.; Bonifacio, P.; Caffau, E.; Geisler,
D.; Marconi, G.; Momany, Y.; Ludwig, H. -G.
2012A&A...539A.157M Altcode: 2011arXiv1108.0138M
Context. The abundance inhomogeneities of light elements observed
in globular clusters (GCs), and notably the ubiquitous Na-O
anti-correlation, are generally interpreted as evidence that GCs
comprise several generations of stars. There is an on-going debate
as to the nature of the stars, which produce the inhomogeneous
elements, and investigating the behavior of several elements is
a way to shed new light on this problem. <BR /> Aims: We aim at
investigating the Li and Na content of the GC M 4, that is known to
have a well defined Na-O anti-correlation. <BR /> Methods: We obtained
moderate resolution (R = 17 000-18 700) spectra for 91 main sequence
(MS)/sub-giant branch stars of M 4 with the Giraffe spectrograph at
the FLAMES/VLT ESO facility. Using model atmospheres analysis we
measured lithium and sodium abundances. <BR /> Results: We detect
a weak Li-Na anti-correlation among un-evolved MS stars. One star
in the sample, # 37934, shows the remarkably high lithium abundance
A(Li) = 2.87, compatible with current estimates of the primordial
lithium abundance. <BR /> Conclusions: The shallow slope found
for the Li-Na anti-correlation suggests that lithium is produced
in parallel to sodium. This evidence, coupled with its sodium-rich
nature, suggests that the high lithium abundance of star # 37934 may
originate by pollution from a previous generations of stars. The
recent detection of a Li-rich dwarf of pollution origin in the
globular cluster NGC 6397 may also point in this direction. Still,
no clear cut evidence is available against a possible preservation
of the primordial lithium abundance for star # 37934. <P />Based on
observations taken at ESO VLT Kueyen telescope (Cerro Paranal, Chile,
program: 085.D-0537A).Table A.1 is available in electronic form at
<A href="http://www.aanda.org">http://www.aanda.org</A>
---------------------------------------------------------
Title: <SUP>6</SUP>Li detection in metal-poor stars: can 3D model
atmospheres solve the second lithium problem?
Authors: Steffen, M.; Cayrel, R.; Caffau, E.; Bonifacio, P.; Ludwig,
H. -G.; Spite, M.
2012MSAIS..22..152S Altcode: 2012arXiv1206.2239S
The presence of <SUP>6</SUP>Li in the atmospheres of metal-poor
halo stars is usually inferred from the detection of a subtle extra
depression in the red wing of the <SUP>7</SUP>Li doublet line at
670.8 nm. However, as pointed out recently by \cite{Cayrel2007},
the intrinsic line asymmetry caused by convective flows in the
photospheres of cool stars is almost indistinguishable from the
asymmetry produced by a weak <SUP>6</SUP>Li blend on a (presumed)
symmetric <SUP>7</SUP>Li profile. Previous determinations of the
<SUP>6</SUP>Li/ <SUP>7</SUP>Li isotopic ratio based on 1D model
atmospheres, ignoring the convection-induced line asymmetry, must
therefore be considered as upper limits. By comparing synthetic
1D LTE and 3D non-LTE line profiles of the <SUP>i</SUP>Li 670.8 nm
feature, we quantify the differential effect of the convective line
asymmetry on the derived <SUP>6</SUP>Li abundance as a function of
effective temperature, gravity, and metallicity. As expected, we
find that the asymmetry effect systematically reduces the resulting
<SUP>6</SUP>Li/<SUP>7</SUP>Li ratios. Depending on the stellar
parameters, the 3D-1D offset in <SUP>6</SUP>Li/<SUP>7</SUP>Li ranges
between -0.005 and -0.020. When this purely theoretical correction is
taken into account for the \cite{A2006} sample of stars, the number of
significant <SUP>6</SUP>Li detections decreases from 9 to 5 (2sigma
criterion), or from 5 to 2 (3sigma criterion). <P />We also present
preliminary results of a re-analysis of high-resolution, high S/N
spectra of individual metal-poor turn-off stars, to see whether the
second Lithium problem actually disappears when accounting properly for
convection and non-LTE line formation in 3D stellar atmospheres. Out
of 8 stars, HD 84937 seems to be the only significant (2sigma )
detection of <SUP>6</SUP>Li. In view of our results, the existence of
a <SUP>6</SUP>Li plateau appears questionable.
---------------------------------------------------------
Title: Lithium abundances in extremely metal-poor turn-off stars
Authors: Sbordone, L.; Bonifacio, P.; Caffau, E.
2012MSAIS..22...29S Altcode: 2012arXiv1206.7008S
We discuss the current status of the sample of Lithium abundances in
extremely metal poor (EMP) turn-off (TO) stars collected by our group,
and compare it with the available literature results. In the last years,
evidences have accumulated of a progressive disruption of the Spite
plateau in stars of extremely low metallicity. What appears to be a
flat, thin plateau above [Fe/H]∼-2.8 turns, at lower metallicities,
into a broader distribution for which the plateau level constitutes
the upper limit, but more and more stars show lower Li abundances. The
sample we have collected currently counts abundances or upper limits for
44 EMP TO stars between [Fe/H]=-2.5 and -3.5, plus the ultra-metal poor
star SDSS J102915+172927 at [Fe/H]=-4.9. The “meltdown” of the Spite
plateau is quite evident and, at the current status of the sample,
does not appear to be restricted to the cool end of the effective
temperature distribution. SDSS J102915+172927 displays an extreme
Li depletion that contrasts with its otherwise quite ordinary set of
[X/Fe] ratios.
---------------------------------------------------------
Title: Observing metal-poor stars with X-Shooter
Authors: Caffau, E.; Bonifacio, P.; Sbordone, L.; Monaco, L.;
François; , P.
2012MmSAI..83.1161C Altcode:
The extremely metal-poor stars (EMP) hold in their atmospheres
the fossil record of the chemical composition of the early phases
of the Galactic evolution. The chemical analysis of such objects
provides important constraints on these early phases. EMP stars are
very rare objects; to dig them out large amounts of data have to
be considered. With an automatic procedure, we analysed objects with
colours of Turn-Off stars from the Sloan Digital Sky Survey to select a
sample of good candidate EMP stars. During the French-Italian GTO of the
spectrograph X-Shooter, we observed a sample of these candidates. We
could confirm the low metallicity of our sample of stars, and we
succeeded in finding a record metal-poor star.
---------------------------------------------------------
Title: Preliminary determination of the Non-LTE Calcium abundance
in a sample of extremely metal-poor stars*
Authors: Spite, M.; Spite, F.; Bonifacio, P.; Caffau, E.; Andrievsky,
S.; Korotin, S.; Cayrel, R.; François, P.
2011sf2a.conf..353S Altcode:
The abundance ratios of the elements found in the extremely metal-poor
stars (EMP) are a test of the yields predicted by the models of
supernovae. For precise comparisons, it is of course preferable to
avoid the approximation of LTE. The difference of LTE and NLTE profiles
is displayed for three strong lines. The NLTE abundances of Ca are
derived from the profiles of about 15 Ca I lines in the EMP giants and
about 10 lines in the turnoff stars. The improved abundance trends
are consistent with a [Ca/Fe] ratio constant vs. [Fe/H], and with a
[Ca/Mg] ratio slightly declining when [Mg/H] increases. Also [Ca/Mg]
presents a scatter larger than [Ca/Fe]. As far as the comparison
with sulfur (another alpha elment) is concerned we find that [S/Ca]
presents a scatter smaller than [S/Mg].
---------------------------------------------------------
Title: SPADES: a Stellar PArameters DEtermination Software
Authors: Posbic, H.; Katz, D.; Caffau, E.; Bonifacio, P.; Sbordone,
L.; Gomez, A.; Arenou, F.
2011sf2a.conf..333P Altcode:
With the large amounts of spectroscopic data available today and
the very large surveys to come (e.g. Gaia), the need for automatic
data analysis software is unquestionable. We thus developed an
automatic spectra analysis program for the determination of stellar
parameters: radial velocity, effective temperature, surface gravity,
micro-turbulence, metallicity and the elemental abundances of the
elements present in the spectral range. Target stars for this software
should include all types of stars. The analysis method relies on a
line by line comparison of the spectrum of a target star to a library
of synthetic spectra. The idea is built on the experience acquired in
developing the TGMET (Katz et al. 1998, Soubiran et al. 2003), ETOILE
(Katz 2001) and Abbo (Bonifacio & Caffau 2003) software.The method
is presented and the performances are illustrated with GIRAFFE-like
simulated spectra with high resolution (R = 25000), with high and low
signal to noise ratios (down to SNR = 30). These spectra should be
close to what could be targeted by the Gaia-ESO Survey (GCDS).
---------------------------------------------------------
Title: X-shooter Finds an Extremely Primitive Star
Authors: Caffau, E.; Bonifacio, P.; François, P.; Sbordone, L.;
Monaco, L.; Spite, M.; Spite, F.; Ludwig, H. -G.; Cayrel, R.; Zaggia,
S.; Hammer, F.; Randich, S.; Molaro, P.; Hill, V.
2011Msngr.146...28C Altcode:
Low-mass extremely metal-poor (EMP) stars hold the fossil record of
the chemical composition of the early phases of the Universe in their
atmospheres. Chemical analysis of such objects provides important
constraints on these early phases. EMP stars are rather rare objects:
to dig them out, large amounts of data have to be considered. We have
analysed stars from the Sloan Digital Sky Survey using an automatic
procedure and selected a sample of good candidate EMP stars, which we
observed with the spectrographs X-shooter and UVES. We could confirm
the low metallicity of our sample of stars, and we succeeded in finding
a record metal-poor star.
---------------------------------------------------------
Title: Sulphur in the metal poor globular cluster NGC 6397
Authors: Koch, A.; Caffau, E.
2011A&A...534A..52K Altcode: 2011arXiv1108.6054K
Sulphur (S) is a non-refractory α-element that is not locked into
dust grains in the interstellar medium. Thus no correction to the
measured, interstellar sulphur abundance is needed and it can be readily
compared to the S content in stellar photospheres. Here we present
the first measurement of sulphur in the metal poor globular cluster
(GC) NGC 6397, as detected in a MIKE/Magellan high signal-to-noise,
high-resolution spectrum of one red giant star. While abundance ratios
of sulphur are available for a larger number of Galactic stars down
to an [Fe/H] of ~ -3.5 dex, no measurements in globular clusters more
metal poor than -1.5 dex have been reported so far. We find aNLTE,
3-D abundance ratio of [S/Fe] = +0.52 ± 0.20 (stat.) ± 0.08 (sys.),
based on theS I, Multiplet 1 line at 9212.8 Å. This value is consistent
with a Galactic halo plateau as typical of other α-elements in GCs
and field stars, but we cannot rule out its membership with a second
branch of increasing [S/Fe] with decreasing [Fe/H], claimed in the
literature, which leads to a large scatter at metallicities around -
2 dex. The [S/Mg] and [S/Ca] ratios in this star are compatible with
a Solar value to within the (large) uncertainties. Despite the very
large scatter in these ratios across Galactic stars between literature
samples, this indicates that sulphur traces the chemical imprints of
the other α-elements in metal poor GCs. Combined with its moderate
sodium abundance ([S/Na]<SUB>NLTE</SUB> = 0.48), the [S/Fe] ratio
in this GC extends a global, positive S-Na correlation that is not
seen in field stars and might indicate that proton-capture reactions
contributed to the production of sulphur in the (metal poor) early GC
environments. <P />This paper includes data gathered with the 6.5 m
Magellan Telescopes located at Las Campanas Observatory, Chile.
---------------------------------------------------------
Title: X-Shooter GTO: chemical analysis of a sample of EMP candidates
Authors: Caffau, E.; Bonifacio, P.; François, P.; Spite, M.; Spite,
F.; Zaggia, S.; Ludwig, H. -G.; Monaco, L.; Sbordone, L.; Cayrel,
R.; Hammer, F.; Randich, S.; Hill, V.; Molaro, P.
2011A&A...534A...4C Altcode: 2011arXiv1109.0992C
Context. Extremely metal-poor stars (EMP) are very rare objects that
hold in their atmospheres the fossil record of the chemical composition
of the early phases of Galactic evolution. Finding these objects and
determining their chemical composition provides important constraints
on these early phases. <BR /> Aims: Using a carefully designed selection
method, we chose a sample of candidate EMP stars from the low resolution
spectra of the Sloan Digital Sky Survey and observed them with X-Shooter
at the VLT to confirm their metallicities and determine abundances
for as many elements as possible. <BR /> Methods: The X-Shooter
spectra are analysed by means of one-dimensional, plane-parallel,
hydrostatic model atmospheres. Corrections for the granulation effects
are computed using CO5BOLD hydrodynamical simulations. <BR /> Results:
All the candidates are confirmed to be EMP stars, proving the efficiency
of our selection method within about 0.5 dex. The chemical composition
of this sample is compatible with those of brighter samples, suggesting
that the stars in the Galactic halo are well mixed. <BR /> Conclusions:
These observations show that it is feasible to observe, in a limited
amount of time, a large sample of about one hundred stars among EMP
candidates selected from the SDSS. Such a size of sample will allow us,
in particular, to confirm or refute the existence of a vertical drop
in the Galactic halo metallicity distribution function around [Fe/H] ~
-3.5. <P />Based on observations obtained at ESO Paranal Observatory,
GTO programme 086.D-0094.
---------------------------------------------------------
Title: An extremely primitive star in the Galactic halo
Authors: Caffau, Elisabetta; Bonifacio, Piercarlo; François, Patrick;
Sbordone, Luca; Monaco, Lorenzo; Spite, Monique; Spite, François;
Ludwig, Hans-G.; Cayrel, Roger; Zaggia, Simone; Hammer, François;
Randich, Sofia; Molaro, Paolo; Hill, Vanessa
2011Natur.477...67C Altcode: 2012arXiv1203.2612C
The early Universe had a chemical composition consisting of
hydrogen, helium and traces of lithium; almost all other elements
were subsequently created in stars and supernovae. The mass fraction
of elements more massive than helium, Z, is known as `metallicity'. A
number of very metal-poor stars has been found, some of which have a
low iron abundance but are rich in carbon, nitrogen and oxygen. For
theoretical reasons and because of an observed absence of stars
with Z<1.5×10<SUP>-5</SUP>, it has been suggested that low-mass
stars cannot form from the primitive interstellar medium until it
has been enriched above a critical value of Z, estimated to lie in
the range 1.5×10<SUP>-8</SUP> to 1.5×10<SUP>-6</SUP> (ref. 8),
although competing theories claiming the contrary do exist. (We
use `low-mass' here to mean a stellar mass of less than 0.8 solar
masses, the stars that survive to the present day.) Here we report the
chemical composition of a star in the Galactic halo with a very low Z
(<=6.9×10<SUP>-7</SUP>, which is 4.5×10<SUP>-5</SUP> times that
of the Sun) and a chemical pattern typical of classical extremely
metal-poor stars--that is, without enrichment of carbon, nitrogen
and oxygen. This shows that low-mass stars can be formed at very low
metallicity, that is, below the critical value of Z. Lithium is not
detected, suggesting a low-metallicity extension of the previously
observed trend in lithium depletion. Such lithium depletion implies
that the stellar material must have experienced temperatures above
two million kelvin in its history, given that this is necessary to
destroy lithium.
---------------------------------------------------------
Title: LTE model atmopsheres MARCS, ATLAS and CO5BOLD
Authors: Bonifacio, Piercarlo; Caffau, Elisabetta; Ludwig,
Hans-Guenter; Steffen, Matthias
2011arXiv1109.0717B Altcode:
In this talk we review the basic assumptions and physics covered by
classical 1D LTE model atmospheres. We will focus on ATLAS and MARCS
models of F-G-K stars and describe what resources are available through
the web, both in terms of codes and model-atmosphere grids. We describe
the advances made in hydrodynamical simulations of convective stellar
atmospheres with the CO5BOLD code and what grids and resources are
available, with a prospect of what will be available in the near future.
---------------------------------------------------------
Title: The Galactic evolution of phosphorus
Authors: Caffau, E.; Bonifacio, P.; Faraggiana, R.; Steffen, M.
2011A&A...532A..98C Altcode: 2011arXiv1107.2657C
Context. As a galaxy evolves, its chemical composition changes and
the abundance ratios of different elements are powerful probes of
the underlying evolutionary processes. Phosphorous is an element
whose evolution has remained quite elusive until now, because it is
difficult to detect in cool stars. The infrared weak P i lines of
the multiplet 1, at 1050-1082 nm, are the most reliable indicators
of the presence of phosphorus. The availability of CRIRES at VLT has
permitted access to this wavelength range in stellar spectra. <BR />
Aims: We attempt to measure the phosphorus abundance of twenty cool
stars in the Galactic disk. <BR /> Methods: The spectra are analysed
with one-dimensional model-atmospheres computed in local thermodynamic
equilibrium (LTE). The line formation computations are performed
assuming LTE. <BR /> Results: The ratio of phosphorus to iron behaves
similarly to sulphur, increasing towards lower metallicity stars. Its
ratio with respect to sulphur is roughly constant and slightly larger
than solar, [P/S] = 0.10 ± 0.10. <BR /> Conclusions: We succeed in
taking an important step towards the understanding of the chemical
evolution of phosphorus in the Galaxy. However, the observed rise in
the P/Fe abundance ratio is steeper than predicted by Galactic chemical
evolution model developed by Kobayashi and collaborators. Phosphorus
appears to evolve differently from the light odd-Z elements sodium
and aluminium. The constant value of [P/S] with metallicity implies
that P production is insensitive to the neutron excess, thus processes
other than neutron captures operate. We suggest that proton captures on
<SUP>30</SUP>Si and α captures on <SUP>27</SUP>Al are possibilities
to investigate. We see no clear distinction between our results for
stars with planets and stars without any detected planet. <P />Based
on observations obtained with the CRIRES spectrograph at ESO-VLT Antu
8.2 m telescope at Paranal, Programme 386.D-0130, P.I. E. Caffau.
---------------------------------------------------------
Title: NGC 1866: a milestone for understanding the chemical evolution
of stellar populations in the Large Magellanic Cloud
Authors: Mucciarelli, A.; Cristallo, S.; Brocato, E.; Pasquini, L.;
Straniero, O.; Caffau, E.; Raimondo, G.; Kaufer, A.; Musella, I.;
Ripepi, V.; Romaniello, M.; Walker, A. R.
2011MNRAS.413..837M Altcode: 2010arXiv1012.1476M
We present new FLAMES@VLT spectroscopic observations of 30 stars in
the field of the Large Magellanic Cloud (LMC) stellar cluster NGC
1866. NGC 1866 is one of the few young and massive globular clusters
that is close enough so that its stars can be individually studied in
detail. Radial velocities have been used to separate stars belonging
to the cluster and to the LMC field, and the same spectra have been
used to derive chemical abundances for a variety of elements, from
[Fe/H] to the light (i.e. Na, O, Mg, etc.) to the heavy ones. The
average iron abundance of NGC 1866 turns out to be [Fe/H]=-0.43 ±
0.01 dex (with a dispersion σ= 0.04 dex), from the analysis of 14
cluster member stars. Within our uncertainties, the cluster stars are
homogeneous, as far as chemical composition is concerned, independent
of the evolutionary status. The observed cluster stars do not show
any sign of the light elements' ‘anticorrelation’ present in all
the Galactic globular clusters so far studied and are also found in
the old LMC stellar clusters. A similar lack of anticorrelations has
been detected in the massive intermediate-age LMC clusters, indicating
a different formation/evolution scenario for the LMC massive clusters
younger than ∼3 Gyr with respect to the old ones. <P />Also opposite
to the Galactic globulars, the chemical composition of the older red
giant branch field stars and of the young post-main-sequence cluster
stars show robust homogeneity suggesting a quite similar process of
chemical evolution. The field and cluster abundances are in agreement
with recent chemical analysis of LMC stars, which show a distinctive
chemical pattern for this galaxy with respect to the Milky Way. We
discuss these findings in light of the theoretical scenario of chemical
evolution of the LMC.
---------------------------------------------------------
Title: First stars. XIV. Sulfur abundances in extremely metal-poor
stars
Authors: Spite, M.; Caffau, E.; Andrievsky, S. M.; Korotin, S. A.;
Depagne, E.; Spite, F.; Bonifacio, P.; Ludwig, H. -G.; Cayrel, R.;
François, P.; Hill, V.; Plez, B.; Andersen, J.; Barbuy, B.; Beers,
T. C.; Molaro, P.; Nordström, B.; Primas, F.
2011A&A...528A...9S Altcode: 2010arXiv1012.4358S
Context. Precise S abundances are important in the study of the
early chemical evolution of the Galaxy. In particular the site of the
formation remains uncertain because, at low metallicity, the trend
of this α-element versus [Fe/H] remains unclear. Moreover, although
sulfur is not bound significantly in dust grains in the ISM, it seems
to behave differently in DLAs and old metal-poor stars. <BR /> Aims:
We attempt a precise measurement of the S abundance in a sample of
extremely metal-poor stars observed with the ESO VLT equipped with
UVES, taking into account NLTE and 3D effects. <BR /> Methods: The
NLTE profiles of the lines of multiplet 1 of S I were computed with a
version of the program MULTI, including opacity sources from ATLAS9
and based on a new model atom for S. These profiles were fitted to
the observed spectra. <BR /> Results: We find that sulfur in EMP stars
behaves like the other α-elements, with [S/Fe] remaining approximately
constant below [Fe/H] = -3. However, [S/Mg] seems to decrease slightly
with increasing [Mg/H]. The overall abundance patterns of O, Na, Mg,
Al, S, and K are most closely matched by the SN model yields by Heger
& Woosley. The [S/Zn] ratio in EMP stars is solar, as also found
in DLAs. We derive an upper limit to the sulfur abundance [S/Fe] <
+0.5 for the ultra metal-poor star CS 22949-037. This, along with a
previously reported measurement of zinc, argues against the conjecture
that the light-element abundance pattern of this star (and by analogy,
the hyper iron-poor stars HE 0107-5240 and HE 1327-2326) would be
due to dust depletion. <P />Based on observations obtained with the
ESO Very Large Telescope at Paranal (Large Programme "First Stars",
ID 165, N-0276, P.I.: Cayrel.
---------------------------------------------------------
Title: Extremely metal-poor stars in SDSS fields
Authors: Bonifacio, P.; Caffau, E.; François, P.; Sbordone, L.;
Ludwig, H. -G.; Spite, M.; Molaro, P.; Spite, F.; Cayrel, R.; Hammer,
F.; Hill, V.; Nonino, M.; Randich, S.; Stelzer, B.; Zaggia, S.
2011AN....332..251B Altcode: 2011arXiv1101.3139B
Some insight on the first generation of stars can be obtained from
the chemical composition of their direct descendants, extremely
metal-poor stars (EMP), with metallicity less than or equal to 1/1000
of the solar metallicity. Such stars are exceedingly rare, the most
successful surveys, for this purpose, have so far provided only about
100 stars with 1/1 000 the solar metallicity and 4 stars with about
1/10 000 of the solar metallicity. The Sloan Digital Sky Survey has
the potential to provide a large number of candidates of extremely
low metallicity. X-shooter has the unique capability of performing the
necessary follow-up spectroscopy providing accurate metallicities and
abundance ratios for several elements (Mg, Al, Ca, Ti, Cr, Sr, ...) for
EMP candidates. We here report on the results for the first two stars
observed in the course of our Franco-Italian X-shooter GTO. The two
stars were targeted to be of metallicity around -3.0, the analysis of
the X-shooter spectra showed them to be of metallicity around -2.0,
but with a low α to iron ratio, which explains the underestimate of
the metallicity from the SDSS spectra. The efficiency of X-shooter
allows an in situ study of the outer halo, for the two stars studied
here we estimate distances of 3.9 and 9.1 kpc, these are likely the
most distant dwarf stars studied in detail to date. <P />Based on
spectra obtained with X-shooter at the 8.2-m Kueyen ESO telescope,
GTO programmes 085.D-0194 and 086.D.0094.
---------------------------------------------------------
Title: The solar photospheric abundance of zirconium
Authors: Caffau, E.; Faraggiana, R.; Ludwig, H. -G.; Bonifacio, P.;
Steffen, M.
2011AN....332..128C Altcode: 2010arXiv1012.1038C
Zirconium (Zr), together with strontium and yttrium, is an important
element in the understanding of the Galactic nucleosynthesis. In
fact, the triad Sr-Y-Zr constitutes the first peak of s-process
elements. Despite its general relevance not many studies of the solar
abundance of Zr were conducted. We derive the zirconium abundance in
the solar photosphere with the same CO<SUP>5</SUP>BOLD hydrodynamical
model of the solar atmosphere that we previously used to investigate
the abundances of C-N-O. We review the zirconium lines available in
the observed solar spectra and select a sample of lines to determine
the zirconium abundance, considering lines of neutral and singly
ionised zirconium. We apply different line profile fitting strategies
for a reliable analysis of Zr lines that are blended by lines of other
elements. The abundance obtained from lines of neutral zirconium is very
uncertain because these lines are commonly blended and weak in the solar
spectrum. However, we believe that some lines of ionised zirconium are
reliable abundance indicators. Restricting the set to Zr II lines,
from the CO<SUP>5</SUP>BOLD 3D model atmosphere we derive A(Zr)
{=2.62± 0.06}, where the quoted error is the RMS line-to-line scatter.
---------------------------------------------------------
Title: Solar Chemical Abundances Determined with a CO5BOLD 3D Model
Atmosphere
Authors: Caffau, E.; Ludwig, H. -G.; Steffen, M.; Freytag, B.;
Bonifacio, P.
2011SoPh..268..255C Altcode: 2010SoPh..tmp...66C; 2010arXiv1003.1190C
In the last decade, the photospheric solar metallicity as determined
from spectroscopy experienced a remarkable downward revision. Part
of this effect can be attributed to an improvement of atomic data and
the inclusion of NLTE computations, but also the use of hydrodynamical
model atmospheres seemed to play a role. This "decrease" with time of
the metallicity of the solar photosphere increased the disagreement
with the results from helioseismology. With a CO<SUP>5</SUP>BOLD 3D
model of the solar atmosphere, the CIFIST team at the Paris Observatory
re-determined the photospheric solar abundances of several elements,
among them C, N, and O. The spectroscopic abundances are obtained by
fitting the equivalent width and/or the profile of observed spectral
lines with synthetic spectra computed from the 3D model atmosphere. We
conclude that the effects of granular fluctuations depend on the
characteristics of the individual lines, but are found to be relevant
only in a few particular cases. 3D effects are not responsible for
the systematic lowering of the solar abundances in recent years. The
solar metallicity resulting from this analysis is Z=0.0153, Z/X=0.0209.
---------------------------------------------------------
Title: Cu I resonance lines in turn-off stars of NGC 6752 and NGC
6397. Effects of granulation from CO5BOLD models
Authors: Bonifacio, P.; Caffau, E.; Ludwig, H. -G.
2010A&A...524A..96B Altcode: 2010arXiv1009.1848B
Context. Copper is an element whose interesting evolution with
metallicity is not fully understood. Observations of copper abundances
rely on a very limited number of lines, the strongest are the Cu I
lines of Mult. 1 at 324.7 nm and 327.3 nm which can be measured even at
extremely low metallicities. <BR /> Aims: We investigate the quality of
these lines as abundance indicators. <BR /> Methods: We measure these
lines in two turn-off (TO) stars in the Globular Cluster NGC 6752 and
two TO stars in the Globular Cluster NGC 6397 and derive abundances
with 3D hydrodynamical model atmospheres computed with the CO5BOLD
code. These abundances are compared to the Cu abundances measured in
giant stars of the same clusters, using the lines of Mult. 2 at 510.5
nm and 578.2 nm. <BR /> Results: The abundances derived from the lines
of Mult. 1 in TO stars differ from the abundances of giants of the same
clusters. This is true both using CO5BOLD models and using traditional
1D model atmospheres. The LTE 3D corrections for TO stars are large,
while they are small for giant stars. <BR /> Conclusions: The Cu I
resonance lines of Mult. 1 are not reliable abundance indicators. It
is likely that departures from LTE should be taken into account to
properly describe these lines, although it is not clear if these alone
can account for the observations. An investigation of these departures
is indeed encouraged for both dwarfs and giants. Our recommendation to
those interested in the study of the evolution of copper abundances is
to rely on the measurements in giants, based on the lines of Mult. 2. We
caution, however, that NLTE studies may imply a revision in all the
Cu abundances, both in dwarfs and giants. <P />Based on observations
made with the ESO Very Large Telescope at Paranal Observatory, Chile
(Programmes 71.D-0155, 75.D-0807, 76.B-0133).
---------------------------------------------------------
Title: The metal-poor end of the Spite plateau. I. Stellar parameters,
metallicities, and lithium abundances
Authors: Sbordone, L.; Bonifacio, P.; Caffau, E.; Ludwig, H. -G.;
Behara, N. T.; González Hernández, J. I.; Steffen, M.; Cayrel, R.;
Freytag, B.; van't Veer, C.; Molaro, P.; Plez, B.; Sivarani, T.; Spite,
M.; Spite, F.; Beers, T. C.; Christlieb, N.; François, P.; Hill, V.
2010A&A...522A..26S Altcode: 2010arXiv1003.4510S
Context. The primordial nature of the Spite plateau is at odds with
the WMAP satellite measurements, implying a primordial Li production
at least three times higher than observed. It has also been suggested
that A(Li) might exhibit a positive correlation with metallicity below
[Fe/H] ~ -2.5. Previous samples studied comprised few stars below
[Fe/H] = -3. <BR /> Aims: We present VLT-UVES Li abundances of 28
halo dwarf stars between [Fe/H] = -2.5 and -3.5, ten of which have
[Fe/H] <-3. <BR /> Methods: We determined stellar parameters and
abundances using four different T<SUB>eff</SUB> scales. The direct
infrared flux method was applied to infrared photometry. Hα wings were
fitted with two synthetic grids computed by means of 1D LTE atmosphere
models, assuming two different self-broadening theories. A grid of Hα
profiles was finally computed by means of 3D hydrodynamical atmosphere
models. The Li i doublet at 670.8 nm has been used to measure A(Li)
by means of 3D hydrodynamical NLTE spectral syntheses. An analytical
fit of A(Li)<SUB>3D, NLTE</SUB> as a function of equivalent width,
T<SUB>eff</SUB>, log g, and [Fe/H] has been derived and is made
available. <BR /> Results: We confirm previous claims that A(Li)
does not exhibit a plateau below [Fe/H] = -3. We detect a strong
positive correlation with [Fe/H] that is insensitive to the choice of
T<SUB>eff</SUB> estimator. From a linear fit, we infer a steep slope
of about 0.30 dex in A(Li) per dex in [Fe/H], which has a significance
of 2-3σ. The slopes derived using the four T<SUB>eff</SUB> estimators
are consistent to within 1σ. A significant slope is also detected
in the A(Li)-T<SUB>eff</SUB> plane, driven mainly by the coolest
stars in the sample (T<SUB>eff</SUB> < 6250), which appear to be
Li-poor. However, when we remove these stars the slope detected in
the A(Li)-[Fe/H] plane is not altered significantly. When the full
sample is considered, the scatter in A(Li) increases by a factor
of 2 towards lower metallicities, while the plateau appears very
thin above [Fe/H] = -2.8. At this metallicity, the plateau lies at
<A(Li)<SUB>3D, NLTE</SUB>> = 2.199±0.086. <BR /> Conclusions:
The meltdown of the Spite plateau below [Fe/H] ~ -3 is established,
but its cause is unclear. If the primordial A(Li) were that derived
from standard BBN, it appears difficult to envision a single depletion
phenomenon producing a thin, metallicity independent plateau above
[Fe/H] = -2.8, and a highly scattered, metallicity dependent
distribution below. That no star below [Fe/H] = -3 lies above the
plateau suggests that they formed at plateau level and experienced
subsequent depletion. <P />Based on observations made with the ESO Very
Large Telescope at Paranal Observatory, Chile (Programmes 076.A-0463
and 077.D-0299).Full Table 3 is available in electronic form at the
CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/522/A26">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/522/A26</A>IDL
code (appendix) is only available in electronic form at <A
href="http://www.aanda.org">http://www.aanda.org</A>
---------------------------------------------------------
Title: Galactic evolution of oxygen. OH lines in 3D hydrodynamical
model atmospheres
Authors: González Hernández, J. I.; Bonifacio, P.; Ludwig, H. -G.;
Caffau, E.; Behara, N. T.; Freytag, B.
2010A&A...519A..46G Altcode: 2010arXiv1005.3754G
Context. Oxygen is the third most common element in the Universe. The
measurement of oxygen lines in metal-poor unevolved stars, in
particular near-UV OH lines, can provide invaluable information
about the properties of the Early Galaxy. <BR /> Aims: Near-UV OH
lines constitute an important tool to derive oxygen abundances in
metal-poor dwarf stars. Therefore, it is important to correctly model
the line formation of OH lines, especially in metal-poor stars, where
3D hydrodynamical models commonly predict cooler temperatures than
plane-parallel hydrostatic models in the upper photosphere. <BR />
Methods: We have made use of a grid of 52 3D hydrodynamical model
atmospheres for dwarf stars computed with the code CO<SUP>5</SUP>BOLD,
extracted from the more extended CIFIST grid. The 52 models cover
the effective temperature range 5000-6500 K, the surface gravity
range 3.5-4.5 and the metallicity range -3 < [Fe/H] < 0. <BR />
Results: We determine 3D-LTE abundance corrections in all 52 3D models
for several OH lines and ion{Fe}{i} lines of different excitation
potentials. These 3D-LTE corrections are generally negative and reach
values of roughly -1 dex (for the OH 3167 with excitation potential
of approximately 1 eV) for the higher temperatures and surface
gravities. <BR /> Conclusions: We apply these 3D-LTE corrections
to the individual O abundances derived from OH lines of a sample
the metal-poor dwarf stars reported in Israelian et al. (1998, ApJ,
507, 805), Israelian et al. (2001, ApJ, 551, 833) and Boesgaard et
al. (1999, AJ, 117, 492) by interpolating the stellar parameters of the
dwarfs in the grid of 3D-LTE corrections. The new 3D-LTE [O/Fe] ratio
still keeps a similar trend as the 1D-LTE, i.e., increasing towards
lower [Fe/H] values. We applied 1D-NLTE corrections to 3D ion{Fe}{i}
abundances and still see an increasing [O/Fe] ratio towards lower
metallicites. However, the Galactic [O/Fe] ratio must be revisited
once 3D-NLTE corrections become available for OH and Fe lines for a
grid of 3D hydrodynamical model atmospheres.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Fe Abundances in metal-poor stars
(Sbordone+ 2010)
Authors: Sbordone, L.; Bonifacio, P.; Caffau, E.; Ludwig, H. -G.;
Behara, N. T.; Gonzalez Hernandez, J. I.; Steffen, M.; Cayrel, R.;
Freytag, B.; van't Veer, C.; Molaro, P.; Plez, B.; Sivarani, T.; Spite,
M.; Spite, F.; Beers, T. C.; Christlieb, N.; Francois, P.; Hill, V.
2010yCat..35220026S Altcode: 2010yCat..35229026S
Line-by-line abundances for FeI and FeII lines used to estimate
metallicity and gravity for the program stars. The first column lists
the star name, then the ion (FeI or FeII) The the wavelength in nm,
the loggf, the measured EW (pm) and the derived abundance assuming the
four stellar parameter sets used in the article, respectively 3D, BA,
ALI and IRFM. <P />(3 data files).
---------------------------------------------------------
Title: Sulphur abundances in halo stars from multiplet 3 at 1045 nm
Authors: Caffau, E.; Sbordone, L.; Ludwig, H. -G.; Bonifacio, P.;
Spite, M.
2010AN....331..725C Altcode: 2010arXiv1003.4914C
Sulphur is a volatile α-element which is not locked into dust grains
in the interstellar medium (ISM). Hence, its abundance does not need
to be corrected for dust depletion when comparing the ISM to the
stellar atmospheres. The abundance of sulphur in the photosphere of
metal-poor stars is a matter of debate: according to some authors,
[S/Fe] versus [Fe/H] forms a plateau at low metallicity, while,
according to other studies, there is a large scatter or perhaps a
bimodal distribution. In metal-poor stars sulphur is detectable by its
lines of multiplet 1 at 920 nm, but this range is heavily contaminated
by telluric absorptions, and one line of the multiplet is blended by the
hydrogen Paschen ζ line. We study the possibility of using multiplet 3
(at 1045 nm) for deriving the sulphur abundance because this range,
now observable at the VLT with the infra-red spectrograph CRIRES,
is little contaminated by telluric absorption and not affected by
blends at least in metal-poor stars. We compare the abundances derived
from multiplets 1 and 3, taking into account NLTE corrections and
3D effects. Here we present the results for a sample of four stars,
although the scatter is less pronounced than in previous analysis,
we cannot find a plateau in [S/Fe], and confirm the scatter of the
sulphur abundance at low metallicity. <P />Using data from CRIRES at
the ESO-VLT, Programme 079.D-0434.
---------------------------------------------------------
Title: Science with GYES: a multifibre high-resolution spectrograph
for the prime focus of the Canada-France-Hawaii Telescope
Authors: Bonifacio, P.; Arenou, F.; Babusiaux, C.; Balkowski,
C.; Bienaymé, O.; Briot, D.; Caffau, E.; Carlberg, R.; Famaey,
B.; François, P.; Frémat, Y.; Gomez, A.; Haywood, M.; Hill, V.;
Katz, D.; Kudritzki, R.; Lallement, R.; de Laverny, P.; Lemasle, B.;
Martayan, C.; Monier, R.; Mourard, D.; Nardetto, N.; Recio Blanco,
A.; Robichon, N.; Robin, A. C.; Rodrigues, M.; Royer, Fr.; Soubiran,
C.; Turon, C.; Venn, K.; Viala, Y.
2010SPIE.7735E..0EB Altcode: 2010SPIE.7735E..13B
We present the scientific motivations for GYES: a high multiplex (of the
order of several hundred), high resolution (about 20 000), spectrograph
to be placed at the prime focus of the CFHT. The main purpose of such
an instrument is to conduct a spectroscopic survey complementary to
the Gaia mission. The final Gaia catalogue (expected around 2020) will
provide accurate distances, proper motions and spectrophotometry for
all the stars down to a magnitude of 20. The spectroscopic instrument on
board the Gaia satellite will provide intermediate resolution (R=11 500)
spectra for stars down to the 17th magnitude. For the fainter stars
there will be no radial velocity information. For all the stars the
chemical information will be limited to a few species. A multifibre
spectrograph at the prime focus of the CFHT will be able to provide
the high resolution spectra for stars fainter than 13th magnitude,
needed to obtain both accurate radial velocities and detailed chemical
abundances. The possible use of GYES will not be limited to Gaia
complementary surveys and we here describe the potentialities of
such an instrument. We describe here how the scientific drivers are
translated into technical requirements. The results of our on-going
feasibility study are described in an accompanying poster.
---------------------------------------------------------
Title: The solar photospheric abundance of carbon. Analysis of atomic
carbon lines with the CO5BOLD solar model
Authors: Caffau, E.; Ludwig, H. -G.; Bonifacio, P.; Faraggiana, R.;
Steffen, M.; Freytag, B.; Kamp, I.; Ayres, T. R.
2010A&A...514A..92C Altcode: 2010arXiv1002.2628C
Context. The analysis of the solar spectra using hydrodynamical
simulations, with a specific selection of lines, atomic data, and method
for computing deviations from local thermodynamical equilibrium, has
led to a downward revision of the solar metallicity, Z. We are using
the latest simulations computed with the CO5BOLD code to reassess
the solar chemical composition. Our previous analyses of the key
elements, oxygen and nitrogen, have not confirmed any extreme downward
revision of Z, as derived in other works based on hydrodynamical
models. <BR /> Aims: We determine the solar photospheric carbon
abundance with a radiation-hydrodynamical CO5BOLD model and compute
the departures from local thermodynamical equilibrium by using the
Kiel code. <BR /> Methods: We measured equivalent widths of atomic C
I lines on high-resolution, high signal-to-noise ratio solar atlases
of disc-centre intensity and integrated disc flux. These equivalent
widths were analysed with our latest solar 3D hydrodynamical simulation
computed with CO5BOLD. Deviations from local thermodynamic equilibrium
we computed in 1D with the Kiel code, using the average temperature
structure of the hydrodynamical simulation as a background model. <BR />
Results: Our recommended value for the solar carbon abundance relies
on 98 independent measurements of observed lines and is A(C)=8.50
± 0.06. The quoted error is the sum of statistical and systematic
errors. Combined with our recent results for the solar oxygen and
nitrogen abundances, this implies a solar metallicity of Z = 0.0154
and Z/X = 0.0211. <BR /> Conclusions: Our analysis implies a solar
carbon abundance that is about 0.1 dex higher than what was found in
previous analyses based on different 3D hydrodynamical computations. The
difference is partly driven by our equivalent width measurements
(we measure, on average, larger equivalent widths than the other work
based on a 3D model), in part because of the different properties of
the hydrodynamical simulations and the spectrum synthesis code. The
solar metallicity we obtain from the CO5BOLD analyses is in slightly
better agreement with the constraints of helioseismology than the
previous 3D abundance results.
---------------------------------------------------------
Title: A 3D-NLTE study of the 670 nm solar lithium feature
Authors: Caffau, Elisabetta; Ludwig, Hans-Günter; Steffen, Matthias;
Bonifacio, Piercarlo
2010IAUS..268..329C Altcode:
We derive the 3D-NLTE lithium abundance in the solar photosphere from
the Lii line at 670 nm as measured in several solar atlases. The Li
abundance is obtained from line profile fitting with 1D/3D-LTE/3D-NLTE
synthetic spectra, considering several possibilities for the
atomic parameters of the lines blending the Li feature. The 670 nm
spectral region shows considerable differences in the two available
disc-centre solar atlases, while the two integrated disc spectra are
very similar. We obtain A(Li)<SUB>3D-NLTE</SUB> = 1.03. The 1D-LTE
abundance is 0.07 dex smaller. The line-lists giving the best fit
for the Sun may fail for other stars, while some line-lists fail to
reproduce the solar profile satisfactorily. We need a better knowledge
of the atomic parameters of the lines blending the Li feature in order
to be able to reproduce both the solar spectrum and the spectra of
other stars. An improved line-list is also required to derive reliable
estimates of the isotopic Li ratio in solar-metallicity stars.
---------------------------------------------------------
Title: Three carbon-enhanced metal-poor dwarf stars from the
SDSS. Chemical abundances from CO<SUP>5</SUP>BOLD 3D hydrodynamical
model atmospheres
Authors: Behara, N. T.; Bonifacio, P.; Ludwig, H. -G.; Sbordone, L.;
González Hernández, J. I.; Caffau, E.
2010A&A...513A..72B Altcode: 2010arXiv1002.1670B
Context. The origin of carbon-enhanced metal-poor stars enriched
with both s and r elements is highly debated. Detailed abundances of
these types of stars are crucial to understand the nature of their
progenitors. <BR /> Aims: The aim of this investigation is to study
in detail the abundances of SDSS J1349-0229, SDSS J0912+0216 and SDSS
J1036+1212, three dwarf CEMP stars, selected from the Sloan Digital
Sky Survey. <BR /> Methods: Using high resolution VLT/UVES spectra
(R ~ 30 000) we determine abundances for Li, C, N, O, Na, Mg, Al,
Ca, Sc, Ti, Cr, Mn, Fe, Co, Ni and 21 neutron-capture elements. We
made use of CO<SUP>5</SUP>BOLD 3D hydrodynamical model atmospheres
in the analysis of the carbon, nitrogen and oxygen abundances. NLTE
corrections for Ci and Oi lines were computed using the Kiel code. <BR
/> Results: We classify SDSS J1349-0229 and SDSS J0912+0216 as CEMP-r+s
stars. SDSS J1036+1212 belongs to the class CEMP-no/s, with enhanced
Ba, but deficient Sr, of which it is the third member discovered to
date. Radial-velocity variations have been observed in SDSS J1349-0229,
providing evidence that it is a member of a binary system. <BR />
Conclusions: The chemical composition of the three stars is generally
compatible with mass transfer from an AGB companion. However, many
details remain difficult to explain. Most notably of those are the
abundance of Li at the level of the Spite plateau in SDSS J1036+1212
and the large over-abundance of the pure r-process element Eu in all
three stars. <P />Based on observations obtained with the ESO Very
Large Telescope at Paranal Observatory, Chile (programmes 078.D-0217
and 383.D-0927).
---------------------------------------------------------
Title: Convection and <SUP>6</SUP>Li in the atmospheres of metal-poor
halo stars
Authors: Steffen, Matthias; Cayrel, R.; Bonifacio, P.; Ludwig, H. -G.;
Caffau, E.
2010IAUS..268..215S Altcode: 2010arXiv1001.3274S
Based on 3D hydrodynamical model atmospheres computed with the
CO<SUP>5</SUP>BOLD code and 3D non-LTE (NLTE) line formation
calculations, we study the effect of the convection-induced line
asymmetry on the derived <SUP>6</SUP>Li abundance for a range in
effective temperature, gravity, and metallicity covering the stars
of the Asplund et al. (2006) sample. When the asymmetry effect
is taken into account for this sample of stars, the resulting
<SUP>6</SUP>Li/<SUP>7</SUP>Li ratios are reduced by about 1.5% on
average with respect to the isotopic ratios determined by Asplund et
al. (2006). This purely theoretical correction diminishes the number
of significant <SUP>6</SUP>Li detections from 9 to 4 (2σ criterion),
or from 5 to 2 (3σ criterion). In view of this result the existence
of a <SUP>6</SUP>Li plateau appears questionable. A careful reanalysis
of individual objects by fitting the observed lithium 6707 Å doublet
both with 3D NLTE and 1D LTE synthetic line profiles confirms that the
inferred <SUP>6</SUP>Li abundance is systematically lower when using
3D NLTE instead of 1D LTE line fitting. Nevertheless, halo stars with
unquestionable <SUP>6</SUP>Li detection do exist even if analyzed in
3D-NLTE, the most prominent example being HD 84937.
---------------------------------------------------------
Title: The metal-poor end of the Spite plateau: gravity sensitivity
of the Hα wings fitting.
Authors: Sbordone, L.; Bonifacio, P.; Caffau, E.; Ludwig, H. -G.;
Behara, N.; Gonzalez-Hernandez, J. I.; Steffen, M.; Cayrel, R.;
Freytag, B.; Van't Veer, C.; Molaro, P.; Plez, B.; Sivarani, T.; Spite,
M.; Spite, F.; Beers, T. C.; Christlieb, N.; François, P.; Hill, V.
2010IAUS..268..355S Altcode:
We recently presented (Sbordone et al., 2009a) the largest sample to
date of lithium abundances in extremely metal-poor (EMP) Halo dwarf and
Turn-Off (TO) stars. One of the most crucial aspects in estimating Li
abundances is the T<SUB>eff</SUB> determination, since the Li I 670.8
nm doublet is highly temperature sensitive. In this short contribution
we concentrate on the T<SUB>eff</SUB> determination based on Hα wings
fitting, and on its sensitivity to the chosen stellar gravity.
---------------------------------------------------------
Title: Main-sequence and sub-giant stars in the globular cluster
NGC 6397: The complex evolution of the lithium abundance
Authors: González Hernández, J. I.; Bonifacio, P.; Caffau, E.;
Steffen, M.; Ludwig, H. -G.; Behara, N.; Sbordone, L.; Cayrel, R.;
Zaggia, S.
2010IAUS..268..257G Altcode: 2009arXiv0912.4105G
Thanks to the high multiplex and efficiency of Giraffe at the VLT
we have been able for the first time to observe the Li I doublet in
the Main Sequence stars of a globular cluster. At the same time we
observed Li in a sample of Sub-Giant stars of the same B-V colour. <P
/>Our final sample is composed of 84 SG stars and 79 MS stars. In
spite of the fact that SG and MS span the same temperature range we
find that the equivalent widths of the Li I doublet in SG stars are
systematically larger than those in MS stars, suggesting a higher Li
content among SG stars. This is confirmed by our quantitative analysis
carried out making use of 1D hydrostatic plane-parallel models and
3D hydrodynamical simulations of the stellar atmospheres. <P />We
derived the effective temperatures of stars in our the sample from Hα
fitting. Theoretical profiles were computed using 3D hydrodynamical
simulations and 1D ATLAS models. Therefore, we are able to determined
1D and 3D-based effective temperatures. We then infer Li abundances
taking into account non-local thermodynamical equilibrium effects when
using both 1D and 3D models. <P />We find that SG stars have a mean
Li abundance higher by 0.1 dex than MS stars. This result is obtained
using both 1D and 3D models. We also detect a positive slope of Li
abundance with effective temperature, the higher the temperature the
higher the Li abundance, both for SG and MS stars, although the slope
is slightly steeper for MS stars. These results provide an unambiguous
evidence that the Li abundance changes with evolutionary status. <P
/>The physical mechanisms responsible for this behaviour are not yet
clear, and none of the existing models seems to describe accurately
these observations. Based on these conclusions, we believe that the
cosmological lithium problem still remains an open question.
---------------------------------------------------------
Title: <SUP>6</SUP>Li in metal-poor halo stars: real or spurious?
Authors: Steffen, M.; Cayrel, R.; Bonifacio, P.; Ludwig, H. -G.;
Caffau, E.
2010IAUS..265...23S Altcode: 2009arXiv0910.5917S
The presence of convective motions in the atmospheres of metal-poor
halo stars leads to systematic asymmetries of the emergent spectral
line profiles. Since such line asymmetries are very small, they can be
safely ignored for standard spectroscopic abundance analysis. However,
when it comes to the determination of the <SUP>6</SUP>Li/<SUP>7</SUP>Li
isotopic ratio, q(Li)=n(<SUP>6</SUP>Li)/n(<SUP>7</SUP>Li), the
intrinsic asymmetry of the <SUP>7</SUP>Li line must be taken into
account, because its signature is essentially indistinguishable from
the presence of a weak <SUP>6</SUP>Li blend in the red wing of the
<SUP>7</SUP>Li line. In this contribution we quantity the error of the
inferred <SUP>6</SUP>Li/<SUP>7</SUP>Li isotopic ratio that arises if
the convective line asymmetry is ignored in the fitting of the λ6707
Å lithium blend. Our conclusion is that <SUP>6</SUP>Li/<SUP>7</SUP>Li
ratios derived by Asplund et al. (2006), using symmetric line profiles,
must be reduced by typically Δq(Li) ≈ 0.015. This diminishes the
number of certain <SUP>6</SUP>Li detections from 9 to 4 stars or less,
casting some doubt on the existence of a <SUP>6</SUP>Li plateau.
---------------------------------------------------------
Title: Can we trust elemental abundances derived in late-type giants
with the classical 1D stellar atmosphere models?
Authors: Kučinskas, A.; Dobrovolskas, V.; Ivanauskas, A.; Ludwig,
H. -G.; Caffau, E.; Blaževičius, K.; Klevas, J.; Prakapavičius, D.
2010IAUS..265..209K Altcode: 2009arXiv0910.3397K
We compare the abundances of various chemical species as derived
with 3D hydrodynamical and classical 1D stellar atmosphere codes in
a late-type giant characterized by T<SUB>eff</SUB> =3640 K, log g =
1.0, [M/H]= 0.0. For this particular set of atmospheric parameters the
3D-1D abundance differences are generally small for neutral atoms and
molecules but they may reach up to 0.3-0.4 dex in case of ions. The
3D-1D differences generally become increasingly more negative at
higher excitation potentials and are typically largest in the optical
wavelength range. Their sign can be both positive and negative, and
depends on the excitation potential and wavelength of a given spectral
line. While our results obtained with this particular late-type giant
model suggest that 1D stellar atmosphere models may be safe to use
with neutral atoms and molecules, care should be taken if they are
exploited with ions.
---------------------------------------------------------
Title: Detailed analyses of three neutron-capture-rich carbon-enhanced
metal-poor stars
Authors: Behara, N. T.; Bonifacio, P.; Ludwig, H. -G.; Sbordone, L.;
González Hernández, J. I.; Caffau, E.
2010IAUS..265..122B Altcode: 2009arXiv0909.0180B
Approximately 20% of very metal-poor stars ([Fe/H] < -2.0)
are strongly enhanced in carbon ([C/Fe] > +1.0). Such stars are
referred to as carbon-enhanced metal-poor (CEMP) stars. We present a
chemical abundance analysis based on high resolution spectra acquired
with UVES at the VLT of three dwarf CEMP stars: SDSS J1349-0229, SDSS
J0912+0216 and SDSS J1036+1212. These very metal-poor stars, with
[Fe/H] < -2.5, were selected from our ongoing survey of extremely
metal-poor dwarf candidates from the SDSS. <P />Among these CEMPs,
SDSS J1349-0229 has been identified as a carbon star ([C/O] >
+1.0). First and second peak s-process elements, as well as second
peak r-process elements have been detected in all stars. In addition,
elements from the third r-process peak were detected in one of the
stars, SDSS J1036+1212. We present the abundance results of these
stars in the context of neutron-capture nucleosynthesis theories.
---------------------------------------------------------
Title: Solar abundances and 3D model atmospheres
Authors: Ludwig, Hans-Günter; Caffau, Elisabetta; Steffen, Matthias;
Bonifacio, Piercarlo; Freytag, Bernd; Cayrel, Roger
2010IAUS..265..201L Altcode: 2009arXiv0911.4248L
We present solar photospheric abundances for 12 elements from optical
and near-infrared spectroscopy. The abundance analysis was conducted
employing 3D hydrodynamical (CO<SUP>5</SUP>BOLD) as well as standard
1D hydrostatic model atmospheres. We compare our results to others
with emphasis on discrepancies and still lingering problems, in
particular exemplified by the pivotal abundance of oxygen. We argue
that the thermal structure of the lower solar photosphere is very
well represented by our 3D model. We obtain an excellent match of
the observed center-to-limb variation of the line-blanketed continuum
intensity, also at wavelengths shortward of the Balmer jump.
---------------------------------------------------------
Title: The metal-poor end of the Spite plateau
Authors: Sbordone, L.; Bonifacio, P.; Caffau, E.; Ludwig, H. -G.;
Behara, N.; Gonzalez-Hernandez, J. I.; Steffen, M.; Cayrel, R.;
Freytag, B.; Van't Veer, C.; Molaro, P.; Plez, B.; Sivarani, T.; Spite,
M.; Spite, F.; Beers, T. C.; Christlieb, N.; François, P.; Hill, V.
2010IAUS..265...75S Altcode:
We present the largest sample available to date of lithium abundances in
extremely metal poor (EMP) Halo dwarfs. Four T<SUB>eff</SUB> estimators
are used, including IRFM and Hα wings fitting against 3D hydrodynamical
synthetic profiles. Lithium abundances are computed by means of 1D and
3D-hydrodynamical NLTE computations. Below [Fe/H]~-3, a strong positive
correlation of A(Li) with [Fe/H] appears, not influenced by the choice
of the Teff estimator. A linear fit finds a slope of about 0.30 dex in
A(Li) per dex in [Fe/H], significant to 2-3 σ, and consistent within
1 σ among all the T<SUB>eff</SUB> estimators. The scatter in A(Li)
increases significantly below [Fe/H]~-3. Above, the plateau lies at
<A(Li)<SUB>3D, NLTE</SUB>> = 2.199 ± 0.086. If the primordial
A(Li) is the one derived from standard Big Bang Nucleosynthesis
(BBN), it appears difficult to envision a single depletion phenomenon
producing a thin, metallicity independent plateau above [Fe/H] = -2.8,
and a highly scattered, metallicity dependent distribution below.
---------------------------------------------------------
Title: Accuracy of spectroscopy-based radioactive dating of stars
Authors: Ludwig, H. -G.; Caffau, E.; Steffen, M.; Bonifacio, P.;
Sbordone, L.
2010A&A...509A..84L Altcode: 2009arXiv0911.4251L
Context. Combined spectroscopic abundance analyses of stable and
radioactive elements can be applied for deriving stellar ages. The
achievable precision depends on factors related to spectroscopy,
nucleosynthesis, and chemical evolution. <BR /> Aims: We quantify the
uncertainties arising from the spectroscopic analysis, and compare these
to the other error sources. <BR /> Methods: We derive formulae for the
age uncertainties arising from the spectroscopic abundance analysis,
and apply them to spectroscopic and nucleosynthetic data compiled
from the literature for the Sun and metal-poor stars. <BR /> Results:
We obtained ready-to-use analytic formulae of the age uncertainty for
the cases of stable+unstable and unstable+unstable chronometer pairs,
and discuss the optimal relation between to-be-measured age and mean
lifetime of a radioactive species. Application to the literature
data indicates that, for a single star, the achievable spectroscopic
accuracy is limited to about ±20% for the foreseeable future. At
present, theoretical uncertainties in nucleosynthesis and chemical
evolution models form the precision bottleneck. For stellar clusters,
isochrone fitting provides a higher accuracy than radioactive dating,
but radioactive dating becomes competitive when applied to many cluster
members simultaneously, reducing the statistical errors by a factor
√{N}. <BR /> Conclusions: Spectroscopy-based radioactive stellar
dating would benefit from improvements in the theoretical understanding
of nucleosynthesis and chemical evolution. Its application to clusters
can provide strong constraints for nucleosynthetic models.
---------------------------------------------------------
Title: GYES, A Multifibre Spectrograph for the CFHT
Authors: Bonifacio, P.; Mignot, S.; Dournaux, J. -L.; François,
P.; Caffau, E.; Royer, F.; Babusiaux, C.; Arenou, F.; Balkowski,
C.; Bienaymé, O.; Briot, D.; Carlberg, R.; Cohen, M.; Dalton,
G. B.; Famaey, B.; Fasola, G.; Frémat, Y.; Gómez, A.; Guinouard,
I.; Haywood, M.; Hill, V.; Huet, J. -M.; Katz, D.; Horville, D.;
Kudritzki, R.; Lallement, R.; Laporte, Ph.; de Laverny, P.; Lemasle,
B.; Lewis, I. J.; Martayan, C.; Monier, R.; Mourard, D.; Nardetto,
N.; Recio Blanco, A.; Robichon, N.; Robin, A. C.; Rodrigues, M.;
Soubiran, C.; Turon, C.; Venn, K.; Viala, Y.
2010EAS....45..219B Altcode: 2011EAS....45..219B; 2010arXiv1009.3644B
We have chosen the name of GYES, one of the mythological giants with
one hundred arms, offspring of Gaia and Uranus, for our instrument
study of a multifibre spectrograph for the prime focus of the
Canada-France-Hawaii Telescope. Such an instrument could provide an
excellent ground-based complement for the Gaia mission and a northern
complement to the HERMES project on the AAT. The CFHT is well known
for providing a stable prime focus environment, with a large field
of view, which has hosted several imaging instruments, but has never
hosted a multifibre spectrograph. Building upon the experience gained
at GÉPI with FLAMES-Giraffe and X-Shooter, we are investigating the
feasibility of a high multiplex spectrograph (about 500 fibres) over a
field of view one degree in diameter. We are investigating an instrument
with resolution in the range 15 000 to 30 000, which should provide
accurate chemical abundances for stars down to 16th magnitude and radial
velocities, accurate to 1 km s<SUP>-1</SUP> for fainter stars. The
study is led by GÉPI-Observatoire de Paris with a contribution from
Oxford for the study of the positioner. The financing for the study
comes from INSU CSAA and Observatoire de Paris. The conceptual study
will be delivered to CFHT for review by October 1st 2010.
---------------------------------------------------------
Title: Chemical abundances in metal-poor giants: limitations imposed
by the use of classical 1D stellar atmosphere models
Authors: Dobrovolskas, V.; Kucinskas, A.; Ludwig, H. G.; Caffau, E.;
Klevas, J.; Prakapavicius, D.
2010nuco.confE.288D Altcode: 2010arXiv1010.2507D; 2010PoS...100E.288D
In this work we have used 3D hydrodynamical (CO5BOLD) and 1D hydrostatic
(LHD) stellar atmosphere models to study the importance of convection
and horizontal temperature inhomogeneities in stellar abundance work
related to late-type giants. We have found that for a number of key
elements, such as Na, Mg, Si, Ca, Ti, Fe, Ni, Zn, Ba, Eu, differences
in abundances predicted by 3D and 1D models are typically minor (<
0.1 dex) at solar metallicity. However, at [M/H] = -3 they become
larger and reach to -0.5...-0.8 dex. In case of neutral atoms and fixed
metallicity, the largest abundance differences were obtained for the
spectral lines with lowest excitation potential, while for ionized
species the largest 3D-1D abundance differences were found for lines
of highest excitation potential. The large abundance differences at
low metallicity are caused by large horizontal temperature fluctuations
and lower mean temperature in the outer layers of the 3D hydrodynamical
model compared with its 1D counterpart.
---------------------------------------------------------
Title: Lithium abundances of main-sequence and subgiant stars in
the globular cluster NGC 6397
Authors: González Hernández, J. I.; Bonifacio, P.; Caffau, E.;
Steffen, M.; Ludwig, H. -G.; Behara, N.; Sbordone, L.; Cayrel, R.;
Zaggia, S.
2010IAUS..266..407G Altcode: 2009arXiv0910.2305G
We present FLAMES/GIRAFFE spectroscopy obtained with the Very Large
Telescope (VLT). Using these observations, we have been able (for the
first time) to observe the Lii doublet in the main-sequence (MS) stars
of a globular cluster. We also observed Li in a sample of subgiant (SG)
stars of the same B - V colour. Our final sample is composed of 84 SG
and 79 MS stars. In spite of the fact that SG and MS stars span the same
temperature range, we find that the equivalent widths of the Lii doublet
in SG stars are systematically greater than in MS stars, suggesting a
higher Li content among SG stars. This is confirmed by our quantitative
analysis, which makes use of both 1D and 3D model atmospheres. We find
that SG stars show, on average, a higher Li abundance, by 0.1 dex, than
MS stars. We also detect a positive slope of Li abundance with effective
temperature: the higher the temperature the higher the Li abundance,
both for SG and MS stars, although the slope is slightly steeper for MS
stars. These results provide unambiguous evidence that the Li abundance
changes with evolutionary state. The physical mechanisms that contribute
to this are not yet clear, since none of the proposed models seem to
describe accurately the observations. Whether such a mechanism can
explain the cosmological lithium problem is still an open question.
---------------------------------------------------------
Title: Sulfur in the globular clusters 47 Tuc and NGC 6752
Authors: Sbordone, L.; Chieffi, A.; Limongi, M.; Caffau, E.; Ludwig,
H. -G.; Bonifacio, P.
2010IAUS..266..537S Altcode:
The light elements Li, O, Na, Al, and Mg are known to show star-to-star
variations in the globular clusters 47 Tuc and NGC 6752. We have
investigated the behavior of the α element sulfur, for which no
previous measurements exist in any Galactic globular cluster. We
used high-resolution UVES spectra of Si multiplet 1 around 923 nm,
and determined S abundances by means of ATLAS static plano-parallel
models. NLTE corrections were applied and 3D corrections were also
computed from co5bold 3D hydrodynamical models. Sulfur has been measured
in four subgiant stars in NGC 6752, leading to an average value of
[S/Fe] = +0.49 ± 0.15 dex, consistent with what is observed in field
stars of similar metallicity. In 47 Tuc, we measured S in four turnoff
(TO) and five subgiant (SG) stars, for an average value of [S/Fe] =
0.18 ± 0.14 dex. While the measurement errors are consistent with a
constant value among all cluster stars analyzed, we detected a highly
significant correlation with sodium abundance, as well as a tentative
one with silicon. The sulfur-sodium correlation is difficult to explain
in terms of nucleosynthesis. Given its high statistical significance,
it is also difficult to dismiss it as fortuitous. Until better data for
more stars are available, the question as to its origin remains open.
---------------------------------------------------------
Title: Local stars formed at z>10: a sample extracted from the SDSS
Authors: Sbordone, L.; Bonifacio, P.; Caffau, E.; Ludwig, H. G.
2010nuco.confE.294S Altcode: 2010arXiv1009.5210S; 2010PoS...100E.294S
As the Universe emerged from its initial hot and dense phase, its
chemical composition was extremely simple, being limited to stable H
and He isotopes, and traces of Li. The first stars that formed had such
initial composition. However, they quickly began to produce a whole
array of heavier nuclei, polluting the interstellar medium. While none
among these first stars has been detected to date, an increasing sample
exists of their direct descendant, stars with heavy elements content of
the order of 1/1000 of the solar value, or less. In most cases, such
stars should have formed at redshift of about 10 or beyond, and their
chemical composition can provide crucial constraints to the nature of
the very first stars. Extremely metal poor (EMP) stars are exceedingly
rare. We used the low resolution spectra obtained by the Sloan Digital
Sky Survey (SDSS) to search for EMP candidates: results of VLT-UVES
high resolution follow-up for 16 of them is presented here. A newly
developed automatic abundance analysis and parameter determination
code, MyGIsFOS, has been employed to analyze the detailed chemical
abundances of such stars.
---------------------------------------------------------
Title: 3D hydrodynamical CO5BOLD model atmospheres of late-type
giants: stellar abundances from molecular lines
Authors: Ivanauskas, A.; Kucinskas, A.; Ludwig, H. G.; Caffau, E.
2010nuco.confE.290I Altcode: 2010PoS...100E.290I; 2010arXiv1010.1722I
We investigate the influence of convection on the formation of
molecular spectral lines in the atmospheres of late-type giants. For
this purpose we use the 3D hydrodynamical CO5BOLD and classical 1D
LHD stellar atmosphere codes and synthesize a number of fictitious
lines belonging to a number of astrophysically relevant molecules, C2,
CH, CN, CO, NH, OH. We find that differences between the abundances
obtained from molecular lines using the 3D and 1D model atmospheres are
generally small at [M/H]=0.0, but they quickly increase at sub-solar
metallicities where for certain molecules they may reach -2.0
dex. The 3D-1D abundance differences show a significant dependence
on the spectral line parameters, such as wavelength and excitation
potential. Our comparison, therefore, reveals a complex interplay
between the spectral line formation and convection that can not be
properly accounted for with the classical 1D model atmospheres.
---------------------------------------------------------
Title: Theoretical amplitudes and lifetimes of non-radial solar-like
oscillations in red giants
Authors: Dupret, M. -A.; Belkacem, K.; Samadi, R.; Montalban, J.;
Moreira, O.; Miglio, A.; Godart, M.; Ventura, P.; Ludwig, H. -G.;
Grigahcène, A.; Goupil, M. -J.; Noels, A.; Caffau, E.
2009A&A...506...57D Altcode: 2009arXiv0906.3951D
Context: Solar-like oscillations have been observed in numerous red
giants from ground and from space. An important question arises:
could we expect to detect non-radial modes probing the internal
structure of these stars? <BR />Aims: We investigate under what physical
circumstances non-radial modes could be observable in red giants; what
would be their amplitudes, lifetimes and heights in the power spectrum
(PS)? <BR />Methods: Using a non-radial non-adiabatic pulsation
code including a non-local time-dependent treatment of convection,
we compute the theoretical lifetimes of radial and non-radial modes
in several red giant models. Next, using a stochastic excitation
model, we compute the amplitudes of these modes and their heights in
the PS. <BR />Results: Distinct cases appear. Case A corresponds to
subgiants and stars at the bottom of the ascending giant branch. Our
results show that the lifetimes of the modes are mainly proportional to
the inertia I, which is modulated by the mode trapping. The predicted
amplitudes are lower for non-radial modes. But the height of the peaks
in the PS are of the same order for radial and non-radial modes as
long as they can be resolved. The resulting frequency spectrum is
complex. Case B corresponds to intermediate models in the red giant
branch. In these models, the radiative damping becomes high enough to
destroy the non-radial modes trapped in the core. Hence, only modes
trapped in the envelope have significant heights in the PS and could
be observed. The resulting frequency spectrum of detectable modes is
regular for ℓ=0 and 2, but a little more complex for ℓ=1 modes
because of less efficient trapping. Case C corresponds to models
of even higher luminosity. In these models the radiative damping of
non-radial modes is even larger than in the previous case and only
radial and non-radial modes completely trapped in the envelope could be
observed. The frequency pattern is very regular for these stars. The
comparison between the predictions for radial and non-radial modes
is very different if we consider the heights in the PS instead of the
amplitudes. This is important as the heights (not the amplitudes) are
used as detection criterion. <P />CIFIST Marie Curie Excellence Team.
---------------------------------------------------------
Title: Lithium in the globular cluster NGC 6397. Evidence for
dependence on evolutionary status
Authors: González Hernández, J. I.; Bonifacio, P.; Caffau, E.;
Steffen, M.; Ludwig, H. -G.; Behara, N. T.; Sbordone, L.; Cayrel,
R.; Zaggia, S.
2009A&A...505L..13G Altcode: 2009arXiv0909.0983G
Context: Most globular clusters are believed to host a single
stellar population. They can thus be considered a good place to
study the Spite plateau and to search for possible evolutionary
modifications of the Li content. <BR />Aims: We want to determine the
Li content of subgiant (SG) and main sequence (MS) stars of the old,
metal-poor globular cluster NGC 6397. This work was aimed not only
at studying possible Li abundance variations but also to investigate
the cosmological Li discrepancy. <BR />Methods: Here, we present
FLAMES/GIRAFFE observations of a sample of 84 SG and 79 MS stars in
NGC 6397 selected in a narrow range of B-V colour and, therefore,
effective temperatures. We determine both effective temperatures and
Li abundances using three-dimensional hydrodynamical model atmospheres
for all the MS and SG stars of the sample. <BR />Results: We find
a significant difference in the Li abundance between SG stars and
MS stars, the SG stars having an abundance higher by almost 0.1
dex on average. We also find a decrease in the lithium abundance
with decreasing effective temperature, both in MS and SG stars,
albeit with a significantly different slope for the two classes of
stars. This suggests that the lithium abundance in these stars is,
indeed, altered by some process, which is temperature-dependent. <BR
/>Conclusions: The lithium abundance pattern observed in NGC 6397 is
different from what is found among field stars, casting some doubt on
the use of globular cluster stars as representative of Population II
with respect to the lithium abundance. None of the available theories
of Li depletion appears to satisfactorily describe our observations. <P
/>Based on observations obtained with FLAMES/GIRAFFE at VLT Kueyen
8.2 m telescope in programme 079.D-0399(A). Table and Figs. 3-10 are
only available in electronic form at http://www.aanda.org Table 2
is available in electronic form at http://www.aanda.org and at the
CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via
http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/505/L13
---------------------------------------------------------
Title: The Solar Photospheric Nitrogen Abundance: Determination with
3D and 1D Model Atmospheres
Authors: Maiorca, E.; Caffau, E.; Bonifacio, P.; Busso, M.; Faraggiana,
R.; Steffen, M.; Ludwig, H. -G.; Kamp, I.
2009PASA...26..345M Altcode: 2009arXiv0912.0375M
We present a new determination of the solar nitrogen abundance
making use of 3D hydrodynamical modelling of the solar photosphere,
which is more physically motivated than traditional static 1D
models. We selected suitable atomic spectral lines, relying on
equivalent width measurements already existing in the literature. For
atmospheric modelling we used the co <SUP>5</SUP> bold 3D radiation
hydrodynamics code. We investigated the influence of both deviations
from local thermodynamic equilibrium (non-LTE effects) and photospheric
inhomogeneities (granulation effects) on the resulting abundance. We
also compared several atlases of solar flux and centre-disc intensity
presently available. As a result of our analysis, the photospheric
solar nitrogen abundance is A(N) = 7.86 +/- 0.12.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Lithium in NGC 6397 (Gonzalez
Hernandez+, 2009)
Authors: Gonzalez Hernandez, J. I.; Bonifacio, P.; Caffau, E.; Steffen,
M.; Ludwig, H. -G.; Behara, N. T.; Sbordone, L.; Cayrel, R.; Zaggia, S.
2009yCat..35059013G Altcode:
Photometric data of the dwarf and subgiant stars of the globular
cluster NGC 6397. We also provide the signal-to-noise of the spectra,
the 3D and 1D Halpha-based effective temperatures, 3D Li abundances,
and the equivalent widths and errors: dEWa: Error of the equivalent
width measurements estimated from a fitting routine that uses as
free parameters the velocity shift, the continuum location, and the
equivalent width of the Li line. dEWb: Error of the equivalent width
associated to the signal-to-noise ratio and the wavelength dispersion
of the spectra, derived using Cayrel's formula (Cayrel, 1988, IAU
Symp. 132: The Impact of Very High S/N Spectroscopy on Stellar Physics,
132, 345). <P />(1 data file).
---------------------------------------------------------
Title: Sulfur in the globular clusters <ASTROBJ>47 Tucanae</ASTROBJ>
and <ASTROBJ>NGC 6752</ASTROBJ>
Authors: Sbordone, L.; Limongi, M.; Chieffi, A.; Caffau, E.; Ludwig,
H. -G.; Bonifacio, P.
2009A&A...503..121S Altcode: 2009arXiv0904.1417S
Context: The light elements Li, O, Na, Al, and Mg are known to
show star-to-star variations in the globular clusters <ASTROBJ>47
Tuc</ASTROBJ> and <ASTROBJ>NGC 6752</ASTROBJ>. Such variations are
interpreted as coming from processing in a previous generation of
stars. <BR />Aims: In this paper we investigate the abundances of
the α-element sulfur, for which no previous measurements exist. In
fact this element has not been investigated in any Galactic globular
cluster so far. The only globular cluster for which such measurements
are available is <ASTROBJ>Terzan 7</ASTROBJ>, which belongs to the
<ASTROBJ>Sgr dSph</ASTROBJ>. <BR />Methods: We use high-resolution
spectra of the S i Mult. 1, acquired with the UVES spectrograph at the
8.2 m VLT-Kueyen telescope, for turn-off and giant stars in the two
globular clusters. The spectra were analysed making use of ATLAS static
plane parallel model atmospheres and SYNTHE spectrum synthesis. We
also compute 3D corrections from CO^5BOLD hydrodynamic models and
apply corrections due to NLTE effects taken from the literature. <BR
/>Results: In the cluster NGC 6752 sulfur has been measured only in
four subgiant stars. We find no significant star-to-star scatter and a
mean <[S/Fe]> = +0.49 ± 0.15, consistent with what is observed in
field stars of the same metallicity. In the cluster 47 Tuc we measured
S in 4 turn-off and 5 subgiant stars with a mean <[S/Fe]> =
+0.18 ± 0.14. While this result is compatible with no star-to-star
scatter we notice a statistically significant correlation of the sulfur
abundance with the sodium abundance and a tentative correlation with
the silicon abundance. <BR />Conclusions: The sulfur-sodium correlation
is not easily explained in terms of nucleosynthesis. An origin due to
atomic diffusion can be easily dismissed. The correlation cannot be
easily dismissed either, in view of its statistical significance, until
better data for more stars is available. <P />Based on observations
made with the ESO VLT-Kueyen telescope at the Paranal Observatory,
Chile, in the course of the ESO-Large Programme 165.L-0263.
---------------------------------------------------------
Title: VizieR Online Data Catalog: Extremely metal-poor turnoff
stars abundances (Bonifacio+, 2009)
Authors: Bonifacio, P.; Spite, M.; Cayrel, R.; Hill, V.; Spite,
F.; Francois, P.; Plez, B.; Ludwig, H. -G.; Caffau, E.; Molaro, P.;
Depagne, E.; Andersen, J.; Barbuy, B.; Beers, T. C.; Nordstroem, B.;
Primas, F.
2009yCat..35010519B Altcode:
The detailed chemical abundances of extremely metal-poor (EMP) stars
are key guides to understanding the early chemical evolution of the
Galaxy. Most existing data, however, treat giant stars that may have
experienced internal mixing later. We aim to compare the results for
giants with new, accurate abundances for all observable elements in
18 EMP turnoff stars. VLT/UVES spectra at ~45000 and S/N ~130 per
pixel (330-1000nm) are analysed with OSMARCS model atmospheres and
the TURBOSPECTRUM code to derive abundances for C, Mg, Si, Ca, Sc,
Ti, Cr, Mn, Co, Ni, Zn, Sr, and Ba. For Ca, Ni, Sr, and Ba, we find
excellent consistency with our earlier sample of EMP giants, at all
metallicities. However, our abundances of C, Sc, Ti, Cr, Mn and Co
are ~0.2dex larger than in giants of similar metallicity. Mg and Si
abundances are ~0.2dex lower (the giant [Mg/Fe] values are slightly
revised), while Zn is again ~0.4dex higher than in giants of similar
[Fe/H] (6 stars only). For C, the dwarf/giant discrepancy could
possibly have an astrophysical cause, but for the other elements it
must arise from shortcomings in the analysis. Approximate computations
of granulation (3D) effects yield smaller corrections for giants than
for dwarfs, but suggest that this is an unlikely explanation, except
perhaps for C, Cr, and Mn. NLTE computations for Na and Al provide
consistent abundances between dwarfs and giants, unlike the LTE results,
and would be highly desirable for the other discrepant elements as
well. Meanwhile, we recommend using the giant abundances as reference
data for Galactic chemical evolution models. <P />(3 data files).
---------------------------------------------------------
Title: First stars XII. Abundances in extremely metal-poor turnoff
stars, and comparison with the giants
Authors: Bonifacio, P.; Spite, M.; Cayrel, R.; Hill, V.; Spite, F.;
François, P.; Plez, B.; Ludwig, H. -G.; Caffau, E.; Molaro, P.;
Depagne, E.; Andersen, J.; Barbuy, B.; Beers, T. C.; Nordström, B.;
Primas, F.
2009A&A...501..519B Altcode: 2009arXiv0903.4174B
Context: The detailed chemical abundances of extremely metal-poor (EMP)
stars are key guides to understanding the early chemical evolution
of the Galaxy. Most existing data, however, treat giant stars that
may have experienced internal mixing later. <BR />Aims: We aim to
compare the results for giants with new, accurate abundances for all
observable elements in 18 EMP turnoff stars. <BR />Methods: VLT/UVES
spectra at R ~ 45 000 and S/N ~ 130 per pixel (λλ 330-1000 nm)
are analysed with OSMARCS model atmospheres and the TURBOSPECTRUM
code to derive abundances for C, Mg, Si, Ca, Sc, Ti, Cr, Mn, Co,
Ni, Zn, Sr, and Ba. <BR />Results: For Ca, Ni, Sr, and Ba, we find
excellent consistency with our earlier sample of EMP giants, at all
metallicities. However, our abundances of C, Sc, Ti, Cr, Mn and
Co are ~0.2 dex larger than in giants of similar metallicity. Mg
and Si abundances are ~0.2 dex lower (the giant [Mg/Fe] values are
slightly revised), while Zn is again ~0.4 dex higher than in giants
of similar [Fe/H] (6 stars only). <BR />Conclusions: For C, the
dwarf/giant discrepancy could possibly have an astrophysical cause,
but for the other elements it must arise from shortcomings in the
analysis. Approximate computations of granulation (3D) effects yield
smaller corrections for giants than for dwarfs, but suggest that this
is an unlikely explanation, except perhaps for C, Cr, and Mn. NLTE
computations for Na and Al provide consistent abundances between dwarfs
and giants, unlike the LTE results, and would be highly desirable for
the other discrepant elements as well. Meanwhile, we recommend using
the giant abundances as reference data for Galactic chemical evolution
models. <P />Based on observations obtained with the ESO Very Large
Telescope at Paranal Observatory, Chile (Large Programme “First
Stars”, ID 165.N-0276; P.I.: R. Cayrel, and Programme 078.B-0238;
P.I.: M. Spite). Appendices A-C are only available in electronic form
at http://www.aanda.org Table 7 is only available in electronic form
at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5)
or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/501/519
---------------------------------------------------------
Title: The solar photospheric nitrogen abundance. Analysis of atomic
transitions with 3D and 1D model atmospheres
Authors: Caffau, E.; Maiorca, E.; Bonifacio, P.; Faraggiana, R.;
Steffen, M.; Ludwig, H. -G.; Kamp, I.; Busso, M.
2009A&A...498..877C Altcode: 2009arXiv0903.3406C
Context: In recent years, the solar chemical abundances have been
studied in considerable detail because of discrepant values of
solar metallicity inferred from different indicators, i.e., on the
one hand, the “sub-solar” photospheric abundances resulting
from spectroscopic chemical composition analyses with the aid of
3D hydrodynamical models of the solar atmosphere, and, on the other
hand, the high metallicity inferred by helioseismology. <BR />Aims:
After investigating the solar oxygen abundance using a CO^5BOLD 3D
hydrodynamical solar model in previous work, we undertake a similar
approach studying the solar abundance of nitrogen, since this element
accounts for a significant fraction of the overall solar metallicity,
Z. <BR />Methods: We used a selection of atomic spectral lines to
determine the solar nitrogen abundance, relying mainly on equivalent
width measurements in the literature. We investigate the influence on
the abundance analysis, of both deviations from local thermodynamic
equilibrium (“NLTE effects”) and photospheric inhomogeneities
(“granulation effects”). <BR />Results: We recommend use of a solar
nitrogen abundance of A(N) = 7.86 ± 0.12, whose error bar reflects
the line-to-line scatter. <BR />Conclusions: The solar metallicity
implied by the CO^5BOLD-based nitrogen and oxygen abundances is in the
range 0.0145≤ Z ≤ 0.0167. This result is a step towards reconciling
photospheric abundances with helioseismic constraints on Z. Our most
suitable estimates are Z=0.0156 and Z/X=0.0213.
---------------------------------------------------------
Title: Observable properties of late-type giants predicted by 3D
hydrodynamical and 1D stellar atmosphere models
Authors: Kucinskas, A.; Ludwig, H. -G.; Ivanauskas, A.; Caffau, E.
2009IAUS..254P..37K Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Halo chemistry and first stars. The chemical composition of
the matter in the early Galaxy, from C to Mg†
Authors: Spite, M.; Bonifacio, P.; Cayrel, R.; Spite, F.; Francois,
P.; Ludwig, H. G.; Caffau, E.; Andrievsky, S.; Barbuy, B.; Plez, B.;
Molaro, P.; Andersen, J.; Beers, T.; Depagne, E.; Nordström, B.;
Primas, F.
2009IAUS..254..349S Altcode:
From NLTE computations of the magnesium abundance in a sample
of extremely metal-poor giants we derive [Mg/Fe]=+0.7, leading to
[Al/Mg]=-0.80 and [Na/Mg]=-0.85 in the early Galaxy. The ratio [O/Mg]
should be near to the solar value. Measurements of nitrogen abundances
derived from the analysis of the NH band in eight more stars confirm
the large scatter of the ratios [N/Fe] and [N/O] in the early Galaxy.
---------------------------------------------------------
Title: Micro- and macroturbulence derived from 3D hydrodynamical
stellar atmospheres .
Authors: Steffen, M.; Ludwig, H. -G.; Caffau, E.
2009MmSAI..80..731S Altcode: 2009arXiv0909.2831S
The theoretical prediction of micro- and macroturbulence (xi_mic
and xi_mac ) as a function of stellar parameters can be useful for
spectroscopic work based on 1D model atmospheres in cases where an
empirical determination of xi_mic is impossible due to a lack of
suitable lines and/or macroturbulence and rotational line broadening
are difficult to separate. In an effort to exploit the CIFIST 3D model
atmosphere grid for deriving the theoretical dependence of xi_mic and
xi_mac on effective temperature, gravity, and metallicity, we discuss
different methods to derive xi_mic from the numerical simulations,
and report first results for the Sun and Procyon. In both cases the
preliminary analysis indicates that the microturbulence found in the
simulations is significantly lower than in the real stellar atmospheres.
---------------------------------------------------------
Title: The ESO Large Programme “First Stars”
Authors: Bonifacio, P.; Andersen, J.; Andrievsky, S. M.; Barbuy, B.;
Beers, T. C.; Caffau, E.; Cayrel, R.; Depagne, E.; François, P.;
González Hernández, J. I.; Hansen, C. J.; Herwig, F.; Hill, V.;
Korotin, S. A.; Ludwig, H. -G.; Molaro, P.; Nordström, B.; Plez,
B.; Primas, F.; Sivarani, T.; Spite, F.; Spite, M.
2009ASSP....9...31B Altcode: 2008arXiv0801.1293B; 2009svlt.conf...31B
In ESO period 65 (April-September 2000) the large programme 165.N-0276,
led by Roger Cayrel, began making use of UVES at the Kueyen VLT
telescope. Known within the Team and outside as "First Stars", it was
aimed at obtaining high resolution, high signal-to-noise ratio spectra
in the range 320 nm-1000 nm for a large sample of extremely metal-poor
(EMP) stars identified from the HK objective prism survey [T.C. Beers,
G.W. Preston, S.A. Shectman in Astron. J. 90, 2089 (1985); T.C. Beers,
G.W. Preston, S.A. Shectman in Astron. J. 103, 1987 (1992)]. The goal
was to use these spectra to determine accurate atmospheric parameters
and chemical composition of these stars which are among the oldest
objects amenable to our detailed study. Although these stars are not
the first generation of stars they must be very close descendants of
the first generation. One may hope to gain insight on the nature of
the progenitors from detailed information on the descendants.
---------------------------------------------------------
Title: The CIFIST 3D model atmosphere grid.
Authors: Ludwig, H. -G.; Caffau, E.; Steffen, M.; Freytag, B.;
Bonifacio, P.; Kučinskas, A.
2009MmSAI..80..711L Altcode: 2009arXiv0908.4496L
Grids of stellar atmosphere models and associated synthetic spectra
are numerical products which have a large impact in astronomy due to
their ubiquitous application in the interpretation of radiation from
individual stars and stellar populations. 3D model atmospheres are
now on the verge of becoming generally available for a wide range
of stellar atmospheric parameters. We report on efforts to develop
a grid of 3D model atmospheres for late-type stars within the CIFIST
Team at Paris Observatory. The substantial demands in computational
and human labor for the model production and post-processing render
this apparently mundane task a challenging logistic exercise. At
the moment the CIFIST grid comprises 77 3D model atmospheres with
emphasis on dwarfs of solar and sub-solar metallicities. While the
model production is still ongoing, first applications are already
worked upon by the CIFIST Team and collaborators.
---------------------------------------------------------
Title: Effects of granulation on neutral copper resonance lines in
metal-poor stars
Authors: Bonifacio, P.; Caffau, E.; Ludwig, H. -G.
2009MmSAI..80..739B Altcode: 2009arXiv0910.4730B
We make use of three dimensional hydrodynamical simulations to
investigate the effects of granulation on the Cu I lines of Mult. 1
in the near UV, at 324.7 nm and 327.3 nm. These lines remain strong
even at very low metallicity and provide the opportunity to study the
chemical evolution of Cu in the metal-poor populations. We find very
strong granulation effects on these lines. In terms of abundances the
neglect of such effects can lead to an overestimate of the A(Cu) by
as much as 0.8 dex in dwarf stars. Comparison of our computations with
stars in the metal-poor Globular Clusters NGC 6752 and NGC 6397, show
that there is a systematic discrepancy between the copper abundances
derived from Mult. 2 in TO stars and those derived in giant stars of the
same cluster from the lines of Mult. 2 at at 510.5 nm and 587.2 nm. We
conclude that the Cu I resonance lines are not reliable indicators of
Cu abundance and we believe that an investigations of departures from
LTE is mandatory to make use of these lines.
---------------------------------------------------------
Title: Solar abundances and granulation effects
Authors: Caffau, E.; Ludwig, H. -G.; Steffen, M.
2009MmSAI..80..643C Altcode: 2009arXiv0910.4733C
The solar abundances have undergone a major downward revision
in the last decade, reputedly as a result of employing 3D
hydrodynamical simulations to model the inhomogeneous structure of
the solar photosphere. The very low oxygen abundance advocated by
\citet{asplund04}, A(O)=8.66, together with the downward revision of
the carbon and nitrogen abundances, has created serious problems for
solar models to explain the helioseismic measurements. <P />In an
effort to contribute to the dispute we have re-derived photospheric
abundances of several elements independently of previous analysis. We
applied a state-of-the art 3D (CO5BOLD) hydrodynamical simulation
of the solar granulation as well as different 1D model atmospheres
for the line by line spectroscopic abundance determinations. The
analysis is based on both standard disc-centre and disc-integrated
spectral atlases; for oxygen we acquired in addition spectra at
different heliocentric angles. The derived abundances are the result
of equivalent width and/or line profile fitting of the available atomic
lines. We discuss the different granulation effects on solar abundances
and compare our results with previous investigations. According to
our investigations hydrodynamical models are important in the solar
abundance determination, but are not responsible for the recent downward
revision in the literature of the solar metallicity.
---------------------------------------------------------
Title: NLTE Abundances of Sodium, Magnesium and Barium in the Globular
Clusters M10 and M71
Authors: Mishenina, T. V.; Kučinskas, A.; Andrievsky, S. M.; Korotin,
S. A.; Dobrovolskas, V.; Ivanauskas, A.; Caffau, E.; Ludwig, H. -G.;
Steffen, M.; Sperauskas, J.; Klochkova, V. G.; Panchuk, V. E.
2009BaltA..18..193M Altcode: 2009OAst...18..193M
We derive NLTE abundances of Na, Mg and Ba in four late-type giants
belonging to globular clusters M10 and M71. The obtained relative
[Na/Fe] ratios, which were measured only in M10, are positive, with
the average value [Na/Fe] = +0.3. The ratios [Mg/Fe] in both clusters
are supersolar, +0.15 to +0.28, while [Ba/Fe] scatter between --0.14
and +0.09. Differences between the NLTE abundances derived in this
work and those obtained in LTE by Mishenina et al. (2003) are small,
typically within ±0.1 dex. We also perform numerical simulations with
the CO<SUP>5</SUP>BOLD 3D hydrodynamical stellar atmosphere code to
investigate the influence of convection on the formation of spectral
lines used in our NLTE study. For this purpose we use a model of
late-type giant with T<SUB></SUB> eff = 4020 K, log g = 1.0, [M/H] =
--1.0 and find that for Na, Mg and Ba the 3D--1D abundance corrections
are below ∼ 0.02 dex. However, their size strongly depends on the
value of microturbulent velocity used with the 1D model.
---------------------------------------------------------
Title: 3D hydrodynamical simulations of stellar photospheres with
the CO<SUP>5</SUP>BOLD code. Photometric colors of a late-type giant
Authors: Kučinskas, A.; Ludwig, H. -G.; Caffau, E.; Steffen, M.
2009MmSAI..80..723K Altcode: 2009arXiv0910.3412K
We present synthetic broad-band photometric colors of a late-type
giant located close to the RGB tip (T_eff≈3640 K, log g=1.0 and
[M/H]=0.0). Johnson-Cousins-Glass BVRIJHK colors were obtained from
the spectral energy distributions calculated using 3D hydrodynamical
and 1D classical stellar atmosphere models. The differences between
photometric magnitudes and colors predicted by the two types of models
are significant, especially at optical wavelengths where they may
reach, e.g., Delta V≈0.16, Delta R≈0.13 and Delta (V-I)≈0.14,
Delta (V-K)≈0.20. Differences in the near-infrared are smaller but
still non-negligible (e.g., Delta K≈ 0.04). Such discrepancies may
lead to noticeably different photometric parameters when these are
inferred from photometry (e.g., effective temperature will change by
Delta T_eff≈60 K due to difference of Delta (V-K)≈0.20).
---------------------------------------------------------
Title: 3D molecular line formation in dwarf carbon-enhanced metal-poor
stars.
Authors: Behara, N. T.; Ludwig, H. -G.; Bonifacio, P.; Sbordone, L.;
González Hernández, J. I.; Caffau, E.
2009MmSAI..80..735B Altcode: 2009arXiv0909.1010B
We present a detailed analysis of the carbon and nitrogen abundances
of two dwarf carbon-enhanced metal-poor (CEMP) stars: SDSS J1349-0229
and SDSS J0912+0216. We also report the oxygen abundance of SDSS
J1349-0229. These stars are metal-poor, with [Fe/H] < -2.5,
and were selected from our ongoing survey of extremely metal-poor
dwarf candidates from the Sloan Digital Sky Survey (SDSS). The carbon,
nitrogen and oxygen abundances rely on molecular lines which form in the
outer layers of the stellar atmosphere. It is known that convection in
metal-poor stars induces very low temperatures which are not predicted
by `classical' 1D stellar atmospheres. To obtain the correct temperature
structure, one needs full 3D hydrodynamical models. Using CO5BOLD 3D
hydrodynamical model atmospheres and the Linfor3D line formation code,
molecular lines of CH, NH, OH and C_2 were computed, and 3D carbon,
nitrogen and oxygen abundances were determined. The resulting carbon
abundances were compared to abundances derived using atomic C I lines
in 1D LTE and NLTE. For one star, SDSS J1349-0229, we were able to
compare the 3D oxygen abundance from OH lines to O I lines in 1D LTE
and NLTE. There is not a good agreement between the carbon abundances
determined from C_2 bands and from the CH band, and molecular lines
do not agree with the atomic C I lines. Although this may be partly
due to uncertainties in the transition probabilities of the molecular
bands it certainly has to do with the temperature structure of the
outer layers of the adopted model atmosphere. In fact the discrepancy
between C_2 and CH is in opposite directions when using 3D and 1D
models. Confronted with this inconsistency, we explore the influence
of the 3D model properties on the molecular abundance determination. In
particular, the choice of the number of opacity bins used in the model
calculations and its subsequent effects on the temperature structure
and molecular line formation is discussed.
---------------------------------------------------------
Title: Extremely metal-poor stars from the SDSS
Authors: Ludwig, H. -G.; Bonifacio, P.; Caffau, E.; Behara, N. T.;
González Hernández, J. I.; Sbordone, L.
2008PhST..133a4037L Altcode: 2008arXiv0809.2948L
We give a progress report on the activities within the CIFIST Team
related to the search for extremely metal-poor (EMP) stars in the
Sloan Digital Sky Survey's (SDSS) spectroscopic catalogue. So far,
the search has provided 25 candidates with metallicities around or
smaller than -3. For 15 candidates, high-resolution spectroscopy with
UVES at the VLT has confirmed their EMP status. Work is under way to
extend the search to the SDSS's photometric catalogue by augmenting
the SDSS photometry and by gauging the capabilities of X-shooter when
going to significantly fainter targets.
---------------------------------------------------------
Title: Radiation-hydrodynamics simulations of surface convection in
low-mass stars: connections to stellar structure and asteroseismology
Authors: Ludwig, Hans-G.; Caffau, Elisabetta; Kučinskas, A.
2008IAUS..252...75L Altcode: 2008arXiv0809.2939L
Radiation-hydrodynamical simulations of surface convection in low-mass
stars can be exploited to derive estimates of i) the efficiency of
the convective energy transport in the stellar surface layers; ii)
the convection-related photometric micro-variability. We comment
on the universality of the mixing-length parameter, and point out
potential pitfalls in the process of its calibration which may be in
part responsible for the contradictory findings about its variability
across the Hertzsprung-Russell digramme. We further comment on the
modelling of the photometric micro-variability in HD 49933 one of the
first main COROT targets.
---------------------------------------------------------
Title: 3D model atmospheres and the solar photospheric oxygen
abundance
Authors: Caffau, E.; Ludwig, H. -G.
2008IAUS..252...35C Altcode:
In recent years the photospheric solar oxygen abundance experienced a
significant downward revision. However, a low photospheric abundance
is incompatible with the value in the solar interior inferred
from helioseismology. For contributing to the dispute whether the
solar oxygen abundance is “high” or “low”, we re-derived its
photospheric abundance independently of previous analyses. We applied
3D (CO5BOLD) as well as 1D model atmospheres. We considered standard
disc-centre and disc-integrated spectral atlases, as well as newly
acquired solar intensity spectra at different heliocentric angles. We
determined the oxygen abundances from equivalent width and/or line
profile fitting of a number of atomic lines. As preliminary result,
we find an oxygen abundance in the range 8.73 8.79, encompassing the
value obtained by Holweger (2001), and somewhat higher than the value
obtained by Asplund et al. (2005).
---------------------------------------------------------
Title: The Solar Photospheric Oxygen Abundance and the Role of 3D
Model Atmospheres
Authors: Caffau, E.; Steffen, M.; Ludwig, H. -G.
2008ESPM...12..3.7C Altcode:
The solar oxygen abundance has undergone a major downward revision in
the last decade, reputedly as a result of employing 3D hydrodynamical
simulations to model the inhomogeneous structure of the solar
photosphere. <P />The very low oxygen abundance advocated by Asplund
et al. 2004, A(O)=8.66, together with the downward revision of the
abundances of other key elements, has created serious problems for solar
models to explain the helioseismic measurements. <P />In an effort to
contribute to the dispute of whether the Sun has "solar" or "sub-solar"
abundances, we have re-derived its photospheric abundance of oxygen,
nitrogen, and other elements, independently of previous analyses. <P
/>We applied a state-of-the art 3D (CO5BOLD) hydrodynamical simulation
of the solar granulation as well as different 1D model atmospheres for
the line by line spectroscopic abundance determinations. The analysis
is based on both standard disk-center and full-disk spectral atlases;
for oxygen we acquired in addition spectra at different heliocentric
angles. The derived abundances are the result of equivalent width
and/or line profile fitting of the available atomic lines. Our
recommended oxygen abundance is A(O)=8.76+- 0.07, 0.1 dex higher
than the value of Asplund et al. (2004). Our current estimate of the
overall solar metallicity is 0.014< Z<0.016. <P />Questions we
discuss include: (i) Is the general downward revision of the solar
abundances a 3D effect? (ii) How large are the abundance corrections
due to horizontal inhomogeneities? (iii) What is the main reason for
the differences between the abundances obtained in our study and those
derived by Apslund and coworkers? (iv) How large are the uncertainties
in the observed solar spectra? (v) What is the reason why the two
forbidden oxygen lines, [OI] lambda 630 nm and [OI] lambda 636.3 nm,
give significantly different answers for the solar oxygen abundance?
---------------------------------------------------------
Title: The photospheric solar oxygen project. I. Abundance analysis
of atomic lines and influence of atmospheric models
Authors: Caffau, E.; Ludwig, H. -G.; Steffen, M.; Ayres, T. R.;
Bonifacio, P.; Cayrel, R.; Freytag, B.; Plez, B.
2008A&A...488.1031C Altcode: 2008arXiv0805.4398C
Context: The solar oxygen abundance has undergone a major downward
revision in the past decade, the most noticeable one being the
update including 3D hydrodynamical simulations to model the solar
photosphere. Up to now, such an analysis has only been carried out
by one group using one radiation-hydrodynamics code. <BR />Aims:
We investigate the photospheric oxygen abundance considering lines
from atomic transitions. We also consider the relationship between
the solar model used and the resulting solar oxygen abundance, to
understand whether the downward abundance revision is specifically
related to 3D hydrodynamical effects. <BR />Methods: We performed
a new determination of the solar photospheric oxygen abundance by
analysing different high-resolution high signal-to-noise ratio atlases
of the solar flux and disc-centre intensity, making use of the latest
generation of CO5BOLD 3D solar model atmospheres. <BR />Results: We
find 8.73 ≤ log (N_O/N_H) +12 ≤ 8.79. The lower and upper values
represent extreme assumptions on the role of collisional excitation
and ionisation by neutral hydrogen for the NLTE level populations
of neutral oxygen. The error of our analysis is ± (0.04± 0.03)
dex, the last being related to NLTE corrections, the first error
to any other effect. The 3D “granulation effects” do not play a
decisive role in lowering the oxygen abundance. <BR />Conclusions:
Our recommended value is log (N_O/N_H) = 8.76 ± 0.07, considering our
present ignorance of the role of collisions with hydrogen atoms on the
NLTE level populations of oxygen. The reasons for lower O abundances in
the past are identified as (1) the lower equivalent widths adopted and
(2) the choice of neglecting collisions with hydrogen atoms in the
statistical equilibrium calculations for oxygen. <P />This paper is
dedicated to the memory of Hartmut Holweger.
---------------------------------------------------------
Title: The solar photospheric abundance of europium. Results from
CO5BOLD 3D hydrodynamical model atmospheres
Authors: Mucciarelli, A.; Caffau, E.; Freytag, B.; Ludwig, H. -G.;
Bonifacio, P.
2008A&A...484..841M Altcode: 2008arXiv0803.0863M
Context: Europium is an almost pure r-process element, which may be
useful as a reference in nucleocosmochronology. <BR />Aims: Determine
the photospheric solar abundance using CO5BOLD 3D hydrodynamical
model atmospheres. <BR />Methods: Disc-centre and integrated-flux
observed solar spectra are used. The europium abundance is derived
using equivalent-width measurements. As a reference, one-dimensional
model atmospheres are in addition used. <BR />Results: The europium
photospheric solar abundance (0.52 ± 0.02) agrees with previous
determinations. We determine the photospheric isotopic fraction of
<SUP>151</SUP>Eu to be 49% ± 2.3% using the intensity spectra, and 50%
± 2.3% using the flux spectra. This compares well to the meteoritic
isotopic fraction 47.8%. We explore 3D corrections for dwarfs and
sub-giants in the temperature range ~5000 K to ~6500 K and solar and
1/10-solar metallicities and find them to be negligible for all models
investigated. <BR />Conclusions: Our photospheric Eu abundance agrees
well with previous determinations based on 1D models. This is in line
with our conclusion that 3D effects for this element are negligible
in the case of the Sun.
---------------------------------------------------------
Title: The solar photospheric abundance of hafnium and
thorium. Results from CO<SUP>5</SUP>BOLD 3D hydrodynamic model
atmospheres
Authors: Caffau, E.; Sbordone, L.; Ludwig, H. -G.; Bonifacio, P.;
Steffen, M.; Behara, N. T.
2008A&A...483..591C Altcode: 2008arXiv0803.3585C
Context: The stable element hafnium (Hf) and the radioactive element
thorium (Th) were recently suggested as a suitable pair for radioactive
dating of stars. The applicability of this elemental pair needs to
be established for stellar spectroscopy. <BR />Aims: We aim at a
spectroscopic determination of the abundance of Hf and Th in the
solar photosphere based on a CO<SUP>5</SUP>BOLD 3D hydrodynamical
model atmosphere. We put this into a wider context by investigating 3D
abundance corrections for a set of G- and F-type dwarfs. <BR />Methods:
High-resolution, high signal-to-noise solar spectra were compared to
line synthesis calculations performed on a solar CO<SUP>5</SUP>BOLD
model. For the other atmospheres, we compared synthetic spectra
of CO<SUP>5</SUP>BOLD 3D and associated 1D models. <BR />Results:
For Hf we find a photospheric abundance A(Hf) = 0.87 ± 0.04, in good
agreement with a previous analysis, based on 1D model atmospheres. The
weak Th II 401.9 nm line constitutes the only Th abundance indicator
available in the solar spectrum. It lies in the red wing of a Ni-Fe
blend exhibiting a non-negligible convective asymmetry. Accounting for
the asymmetry-related additional absorption, we obtain A(Th) = 0.08 ±
0.03, consistent with the meteoritic abundance, and about 0.1 dex lower
than obtained in previous photospheric abundance determinations. <BR
/>Conclusions: Only for the second time, to our knowledge, has a
non-negligible effect of convective line asymmetries on an abundance
derivation been highlighted. Three-dimensional hydrodynamical
simulations should be employed to measure Th abundances in dwarfs
if similar blending is present, as in the solar case. In contrast,
3D effects on Hf abundances are small in G- to mid F-type dwarfs and
sub-giants, and 1D model atmospheres can be conveniently used.
---------------------------------------------------------
Title: Hydrodynamical Model Atmospheres of Metal-Poor Stars
Authors: Ludwig, Hans-Günter; González Hernández, Jonay I.; Behara,
Natalie; Caffau, Elisabetta; Steffen, Matthias
2008AIPC..990..268L Altcode:
Standard one-dimensional (1D) model atmospheres rely on the assumption
of radiative equilibrium in the non-convective part of the stellar
photosphere. However, gas-dynamical effects can lead to dramatic
deviations from radiative equilibrium conditions, especially in
metal-poor stellar atmospheres. These can be taken into account in
3D stellar atmosphere models representing the detailed interplay of
hydrodynamics and radiation. During the last two years efforts have been
invested to compute such 3D models for metal-poor atmospheres with the
CO<SUP>5</SUP> BOLD code within the CIFIST (Cosmological Impact of the
FIrst STars) Team, an European Union funded research group dedicated
to the study of metal-poor stars. Based on the available models we will
give an account of the radiation-hydrodynamical processes at work, and
discuss consequences for the temperature scale and abundance analysis
of metal-poor stars.
---------------------------------------------------------
Title: First stars XI. Chemical composition of the extremely
metal-poor dwarfs in the binary CS 22876-032
Authors: González Hernández, J. I.; Bonifacio, P.; Ludwig, H. -G.;
Caffau, E.; Spite, M.; Spite, F.; Cayrel, R.; Molaro, P.; Hill, V.;
François, P.; Plez, B.; Beers, T. C.; Sivarani, T.; Andersen, J.;
Barbuy, B.; Depagne, E.; Nordström, B.; Primas, F.
2008A&A...480..233G Altcode: 2007arXiv0712.2949G
Context: Unevolved metal-poor stars constitute a fossil record of the
early Galaxy, and can provide invaluable information on the properties
of the first generations of stars. Binary systems also provide direct
information on the stellar masses of their member stars. <BR />Aims:
The purpose of this investigation is a detailed abundance study of the
double-lined spectroscopic binary CS 22876-032, which comprises the two
most metal-poor dwarfs known. <BR />Methods: We used high-resolution,
high-S/N ratio spectra from the UVES spectrograph at the ESO VLT
telescope. Long-term radial-velocity measurements and broad-band
photometry allowed us to determine improved orbital elements and
stellar parameters for both components. We used OSMARCS 1D models and
the turbospectrum spectral synthesis code to determine the abundances
of Li, O, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Fe, Co and Ni. We also
used the CO^5BOLD model atmosphere code to compute the 3D abundance
corrections, notably for Li and O. <BR />Results: We find a metallicity
of [Fe/H] ~ -3.6 for both stars, using 1D models with 3D corrections of
~-0.1 dex from averaged 3D models. We determine the oxygen abundance
from the near-UV OH bands; the 3D corrections are large, -1 and -1.5
dex for the secondary and primary respectively, and yield [O/Fe] ~
0.8, close to the high-quality results obtained from the [OI] 630
nm line in metal-poor giants. Other [ α/Fe] ratios are consistent
with those measured in other dwarfs and giants with similar [Fe/H],
although Ca and Si are somewhat low ([X/Fe] ⪉ 0). Other element
ratios follow those of other halo stars. The Li abundance of the
primary star is consistent with the Spite plateau, but the secondary
shows a lower abundance; 3D corrections are small. <BR />Conclusions:
The Li abundance in the primary star supports the extension of the Spite
Plateau value at the lowest metallicities, without any decrease. The
low abundance in the secondary star could be explained by endogenic
Li depletion, due to its cooler temperature. If this is not the case,
another, yet unknown mechanism may be causing increased scatter in A(Li)
at the lowest metallicities.
---------------------------------------------------------
Title: CS 22876-032: The Most Metal-Poor Dwarfs. Abundances and
3D Effects
Authors: González Hernández, J. I.; Bonifacio, P.; Ludwig, H. -G.;
Caffau, E.; Spite, M.; Spite, F.; Cayrel, R.; Molaro, P.; Hill, V.;
François, P.; Plez, B.; Beers, T. C.; Sivarani, T.; Andersen, J.;
Barbuy, B.; Depagne, E.; Nordström, B.; Primas, F.
2008AIPC..990..175G Altcode: 2008AIPC..990..175H
Unevolved extremely metal-poor stars offer us a unique tool to infer
knowledge of the first generation of stars. We have analysed UVES
high-resolution spectra of the double-lined spectroscopic binary CS
22876-032 which comprises the two most metal-poor dwarfs currently
known. In particular, we determine the oxygen (from OH lines in the
near-UV) and lithium abundances taking into account 3D effects. <P
/>The long-time baseline radial velocity measurements and photometric
data available allowed us to determine the orbital elements as well as
stellar parameters of both components. We use OSMARCS 1D models and the
TURBOSPECTRUM spectral synthesis code to determine the abundances of Li,
O, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Fe, Co and Ni. We also use the
CO<SUP>5</SUP> BOLD 3D model atmosphere code to predict the 3D abundance
corrections, mainly for Li, O and Fe. <P />We find a metallicity
of [Fe/H]~-3.6 for both stars using 1D models with 3D corrections
of ~-0.1 dex from horizontal and temporal averaged 3D models. The
[α/Fe] ratios are consistent with those found for metal-poor giants
with similar [Fe/H], although Ca and Si are rather low, [X/Fe]~=0. The
1D O abundance, [O/Fe]~2 for both stars, is very large, but 3D models
predict abundance corrections of roughly -1.0 dex and -1.5 dex for the
secondary and primary stars, respectively. These 3D corrections bring
the O abundances derived from near-UV OH bands in these two dwarfs
closer to other high-quality measurements from the forbidden [OI]
630 nm line in metal-poor giants. The Li abundance is consistent with
the Spite plateau, although the secondary star shows a lower abundance.
---------------------------------------------------------
Title: Spectral analyses of three carbon-enhanced metal-poor stars
Authors: Behara, N.; Bonifacio, P.; Ludwig, H. G.; Sbordone, L.;
Gonzales Hernandez, J. I.; Caffau, E.
2008nuco.confE..68B Altcode: 2008arXiv0809.4204B; 2008PoS....53E..68B
We are conducting a high-resolution follow-up of candidate EMP stars
extracted from the Sloan Digital Sky Survey (SDSS; York et al. 2000)
using UVES at the VLT. Three of the programme stars, SDSS J0912+0216,
SDSS J1036+1212 and SDSS J1349-0229, where deliberately targetted as
CEMP stars since a strong $G$ band was evident from the SDSS spectra
and the weakness of the Ca {\sc ii} K line testified their very
low metallicity. The UVES high resolution follow-up confirmed the
original findings ([Fe/H] $<-2.50$) and allowed a more detailed
investigation of their chemical composition. We determined the carbon
abundance from molecular lines which form in the outer layers of the
stellar atmosphere. It is known that convection in metal-poor stars
induces very low temperatures which are not predicted by classical
1D stellar atmospheres. To obtain the correct temperature structure,
one needs full 3D hydrodynamical models. 3D carbon abundances were
determined for all three stars, using CO$^5$BOLD 3D hydrodynamical
model atmospheres. 3D effects on the carbon abundance are found to be
quite significant for these stars, with 3D corrections of up to --0.7
dex. Two of the stars, SDSS J0912+0216 and SDSS J1349-0229 exhibit
an overabundance of neutron capture elements which classifies them as
CEMP-s. Star SDSS J1036+1212, instead belongs to the elusive class of
CEMP-no/s stars, with enhanced Ba, but deficient Sr, of which it is
the third member discovered to date.
---------------------------------------------------------
Title: Overview of the Li problem in metal-poor stars and new results
on 6Li
Authors: Cayrel, R.; Steffen, M.; Bonifacio, P.; Ludwig, H. -G.;
Caffau, E.
2008nuco.confE...2C Altcode: 2008arXiv0810.4290C; 2008PoS....53E...2C
Two problems are discussed here. The first one is the 0.4 dex
discrepancy between the 7Li abundance derived from the spectra
of metal-poor halo stars on the one hand, and from Big Bang
nucleosynthesis, based on the cosmological parameters constrained
by the WMAP measurements, on the other hand. Lithium, indeed,
can be depleted in the convection zone of unevolved stars. The
understanding of the hydrodynamics of the crucial zone near the
bottom of the convective envelope in dwarfs or turn-off stars of solar
metallicity has recently made enormous progress with the inclusion of
internal gravity waves. However, similar work for metal-poor stars is
still lacking. Therefore it is not yet clear whether the depletion
occurring in the metal-poor stars themselves is adequate to produce
a 7Li plateau. The second problem pertains to the large amount of
6Li recently found in metal-poor halo stars. The convection-related
asymmetry of the 7Li line could mimic the signal attributed so far
to the weak blend of 6Li in the red wing of the 7Li line. Theoretical
computations show that the signal generated by the asymmetry of 7Li is
2.0, 2.1, and 3.7 per cent for [Fe/H]= -3.0, -2.0, -1.0, respectively
(Teff =6250 K and log g=4.0 [cgs]). In addition we re-investigate
the statistical properties of the 6Li plateau and show that previous
analyses were biased. Our conclusion is that the 6Li plateau can be
reinterpreted in terms of intrinsic line asymmetry, without the need
to invoke a contribution of 6Li. (abridged)
---------------------------------------------------------
Title: The solar photospheric abundance of phosphorus: results from
CO^5BOLD 3D model atmospheres
Authors: Caffau, E.; Steffen, M.; Sbordone, L.; Ludwig, H. -G.;
Bonifacio, P.
2007A&A...473L...9C Altcode: 2007arXiv0708.1607C
Aims:We determine the solar abundance of phosphorus using CO^5BOLD
3D hydrodynamic model atmospheres. <BR />Methods: High-resolution,
high signal-to-noise solar spectra of the P i lines of Multiplet 1 at
1051-1068 nm are compared to line-formation computations performed
on a CO^5BOLD solar model atmosphere. <BR />Results: We find A(P)
= 5.46 ± 0.04, in good agreement with previous analyses based on
1D model atmospheres, due to the P i lines of Mult. 1 not being
affected much by 3D effects. We cannot confirm an earlier claim by
other authors of a downward revision of the solar P abundance by 0.1
dex when employing a 3D model atmosphere. Concerning other stars,
we find modest (<0.1 dex) 3D abundance corrections for P among
four F-dwarf model atmospheres of different metallicities, and these
corrections are largest at lowest metallicity. <BR />Conclusions:
We conclude that 3D abundance corrections are generally rather small
for the P i lines studied in this work. They are marginally relevant
for metal-poor stars, but may be neglected in the Sun. <P />Tables
2-4 are only available in electronic form at http://www.aanda.org
---------------------------------------------------------
Title: Line shift, line asymmetry, and the ^6Li/^7Li isotopic ratio
determination
Authors: Cayrel, R.; Steffen, M.; Chand, H.; Bonifacio, P.; Spite,
M.; Spite, F.; Petitjean, P.; Ludwig, H. -G.; Caffau, E.
2007A&A...473L..37C Altcode: 2007arXiv0708.3819C
Context: Line asymmetries are generated by convective Doppler shifts in
stellar atmospheres, especially in metal-poor stars, where convective
motions penetrate to higher atmospheric levels. Such asymmetries are
usually neglected in abundance analyses. The determination of the
^6Li/^7Li isotopic ratio is prone to suffering from such asymmetries,
as the contribution of ^6Li is a slight blending reinforcement of the
red wing of each component of the corresponding ^7Li line, with respect
to its blue wing. <BR />Aims: The present paper studies the halo star
HD 74000 and estimates the impact of convection-related asymmetries
on the Li isotopic ratio determination. <BR />Methods: Two methods
are used to meet this aim. The first, which is purely empirical,
consists in deriving a template profile from another element that can
be assumed to originate in the same stellar atmospheric layers as Li
I, producing absorption lines of approximately the same equivalent
width as individual components of the ^7Li I resonance line. The
second method consists in conducting the abundance analysis based on
NLTE line formation in a 3D hydrodynamical model atmosphere, taking
into account the effects of photospheric convection. <BR />Results:
The results of the first method show that the convective asymmetry
generates an excess absorption in the red wing of the ^7Li absorption
feature that mimics the presence of ^6Li at a level comparable to
the hitherto published values. This opens the possibility that only
an upper limit on ^6Li/^7Li has thus far been derived. The second
method confirms these findings. <BR />Conclusions: From this work,
it appears that a systematic reappraisal of former determinations of
^6Li abundances in halo stars is warranted. <P />Based on observations
carried out at the European Southern Observatory (ESO), under prog. ID
75.D-0600. Tables 1-3, and additional references are only available
in electronic form at http://www.aanda.org
---------------------------------------------------------
Title: UV flux distributions of γ Doradus stars
Authors: Gerbaldi, M.; Faraggiana, R.; Caffau, E.
2007A&A...472..241G Altcode:
Context: It seems that the recently identified class of pulsating
stars, the γ Dor type-variables, includes objects with different metal
abundances and a large percentage of binaries. <BR />Aims: We looked
for indicators of metal abundance peculiarities and stellar binarity
in a sample of 40 confirmed γ Dor stars. <BR />Methods: Absolute
magnitudes from Hipparcos parallaxes and UV magnitudes, from the S2/S68
experiment on board the TD1 satellite, are retrieved from databases
and compared with predicted values. A set of non variable normal stars
is used to check the consistency of this analysis and also serve as
reference stars. <BR />Results: Twenty-nine stars of the γ Dor star
sample, which is 73% of it, are discovered having abnormal UV fluxes
constantly showing UV flux excesses compared to those computed with
the atmospheric parameters (T<SUB>eff </SUB>, log g, and metallicity)
determined from calibration of the uvbyβ indices. The reason for this
UV excess of flux at 196.5 nm and at 236.5 nm, which was previously
known only for HD 209295, cannot be ascribed to binarity alone. An
extra source of UV flux or less UV absorption - yet unknown - must
be present. <P />Tables 1-3 are only available in electronic form
at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5)
or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/472/241
---------------------------------------------------------
Title: Sulphur abundances from the S i near-infrared triplet at
1045 nm
Authors: Caffau, E.; Faraggiana, R.; Bonifacio, P.; Ludwig, H. -G.;
Steffen, M.
2007A&A...470..699C Altcode: 2007arXiv0704.2335C
Context: Unlike silicon and calcium, sulphur is an α-element
that does not form dust. Some of the available observations of
the evolution of sulphur with metallicity indicate an increased
scatter of sulphur-to-iron ratios at low metallicities or even
a bimodal distribution, with some stars showing constant S/Fe at
all metallicities and others showing an increasing S/Fe ratio with
decreasing metallicity. In metal-poor stars S i lines of Multiplet
1 at 920 nm are not yet too weak to permit the measurement of the
sulphur abundance A(S); however, in ground-based observations they
are severely affected by telluric lines. <BR />Aims: We investigate
the possibility of measuring sulphur abundances from S iMult. 3 at
1045 nm lines. These lie in the near infrared and are slightly weaker
than those of Mult. 1, but lie in a range not affected by telluric
lines. <BR />Methods: We investigated the lines of Mult. 3 in the Sun
(G2V), Procyon (F5V), HD 33256 (F5V), HD 25069 (G9V), and ɛ Eri (HD
22049, K2V). For the Sun and Procyon the analysis was performed with
CO^5BOLD 3D hydrodynamical model atmospheres, while the three other
stars, for which hydrodynamical simulations are not available, were
analysed using 1D model atmospheres. <BR />Results: For our sample of
stars we find a global agreement between A(S) from lines of different
multiplets. <BR />Conclusions: Our results suggest that the infrared
lines of Mult. 3 are a viable indicator of the sulphur abundance
that, because of the intrinsic strength of this multiplet, should be
suitable for studying the trend of [S/Fe] at low metallicities. <P
/>Based on data from the UVES Paranal Observatory Project (ESO DDT
Program ID 266.D-5655). Appendix is only available in electronic form
at http://www.aanda.org
---------------------------------------------------------
Title: VizieR Online Data Catalog: UV Flux distributions of gamma
Dor stars (Gerbaldi+, 2007)
Authors: Gerbaldi, M.; Faraggiana, R.; Caffau, E.
2007yCat..34720241G Altcode:
Reddening and atmospheric parameters (Teff, logg, metallicity,
and visual absolute magnitude) for the gamma Dor stars and a set of
reference stars. <P />(4 data files).
---------------------------------------------------------
Title: The forbidden 1082 nm line of sulphur:. the photospheric
abundance of sulphur in the Sun and 3D effects
Authors: Caffau, E.; Ludwig, H. -G.
2007A&A...467L..11C Altcode: 2007astro.ph..3423C
Context: Sulphur is an element which is formed in the α-process and
is easily measured in the gaseous phase in external galaxies. Since
it does not form dust, it is the preferred indicator for α-elements,
rather than Si or Mg, for which dust corrections are necessary. The
measurement of the sulphur abundance in stars is not an easy
task, relying mainly on high excitation lines with non-negligible
deviations from LTE. The 1082 nm sulphur forbidden transition is
less sensitive to departures from LTE and is less dependent on
temperature uncertainties than other sulphur lines usually employed
as abundance indicators. Therefore it should provide a more robust
abundance diagnostics. <BR />Aims: To derive the solar photospheric
abundance of sulphur from the 1082 nm [SI] line and to investigate
3D effects present in G- and F-type atmospheres at solar and lower
metallicity. <BR />Methods: High-resolution, high signal-to-noise
solar intensity and flux spectra were used to measure the sulphur
abundance from the [SI] 1082 nm line. CO^5BOLD hydrodynamical model
atmospheres were applied to predict 3D abundance corrections for the
[SI] line. <BR />Results: The solar sulphur abundance is derived to be
7.15± (0.01)_stat ± (0.05)_sys, where the statistical uncertainty
represents the scatter in the determination using four different
solar spectra and the systematic uncertainty is due to the modelling
of the blending lines. Sulphur abundances obtained from this line are
insensitive to the micro-turbulence. 3D abundance corrections, found
from strictly differential comparisons between 1D and 3D models, are
negligible in the Sun, but become sizable for more metal-poor dwarfs.
---------------------------------------------------------
Title: Abundances in Sagittarius Stars
Authors: Bonifacio, P.; Zaggia, S.; Sbordone, L.; Santin, P.; Monaco,
L.; Monai, S.; Molaro, P.; Marconi, G.; Girardi, L.; Ferraro, F.;
di Marcantonio, P.; Caffau, E.; Bellazzini, M.
2006cams.book..232B Altcode:
The Sagittarius dwarf spheroidal is a very complex galaxy, which has
undergone prolonged star formation. From the very first high resolution
chemical analysis of Sgr stars, conducted using spectra obtained
during the commissioning of UVES at VLT, it was clear that the star had
undergone a high level of chemical processing, at variance with most
of the other Local Group dwarf spheroidals. Thanks to FLAMES at VLT we
now have accurate metallicities and abundances of alpha-chain elements
for about 150 stars, which provide the first reliable metallicity
distribution for this galaxy. Besides the already known high metallicity
tail the existence of a metal-poor population has also been highlighted,
although an assessment of the fraction of Sgr stars which belong to
this population requires a larger sample. From our data it is also
obvious that Sagittarius is a nucleated galaxy and that the centre of
the nucleus coincides with M54, as already shown by Monaco et al.
---------------------------------------------------------
Title: Sulphur abundance in Galactic stars
Authors: Caffau, E.; Bonifacio, P.; Faraggiana, R.; François, P.;
Gratton, R. G.; Barbieri, M.
2005A&A...441..533C Altcode: 2005astro.ph..7030C
We investigate sulphur abundance in 74 Galactic stars by using high
resolution spectra obtained at ESO VLT and NTT telescopes. For the first
time the abundances are derived, where possible, from three optical
multiplets: Mult. 1, 6, and 8. By combining our own measurements
with data in the literature we assemble a sample of 253 stars in the
metallicity range -3.2 ⪉ [Fe/H] ⪉ +0.5. Two important features,
which could hardly be detected in smaller samples, are obvious from this
large sample: 1) a sizeable scatter in [S/Fe] ratios around [Fe/H]∼
-1; 2) at low metallicities we observe stars with [S/Fe]∼ 0.4, as
well as stars with higher [S/Fe] ratios. The latter do not seem to be
kinematically different from the former ones. Whether the latter finding
stems from a distinct population of metal-poor stars or simply from
an increased scatter in sulphur abundances remains an open question.
---------------------------------------------------------
Title: Sulphur abundances in Terzan 7
Authors: Caffau, E.; Bonifacio, P.; Faraggiana, R.; Sbordone, L.
2005A&A...436L...9C Altcode: 2005astro.ph..4463C
We present here the first measurements of sulphur abundances in
extragalactic stars. We make use of high resolution spectra, obtained
with UVES at the ESO 8.2 m Kueyen telescope, of three giants of the
Globular Cluster Terzan 7, which belongs to the Sagittarius dwarf
galaxy. We measure the sulphur abundances using the lines of S I
multiplet 1. The S/Fe ratios for all three stars are nearly solar, thus
considerably lower than what is found in Galactic stars of comparable
iron content ([Fe/H] ∼ -0.50). This finding is in keeping with the
abundances of other α-chain elements in this cluster and in Sagittarius
and other dSphs in general. These low α-chain elements to iron ratios
suggest that Sagittarius and its Globular Clusters have experienced a
low or bursting star-formation rate. Our sulphur abundances imply <
log (S/O)> = -1.61 which is comparable to what is found in many
H II regions of similar oxygen content, and is slightly lower than
the solar value (log (S/O)<SUB>⊙</SUB> = -1.51). These are also
the first measurements of sulphur abundances in a Globular Cluster,
thus a direct comparison of Terzan 7 and Galactic Globular Clusters
is not possible yet. However our analysis suggests that the lines of
S I multiplet 1 should be measurable for other Globular Clusters at
least down to a metallicity ~-1.5.
---------------------------------------------------------
Title: The Sagittarius dwarf mass-to-light ratio
Authors: Zaggia, S.; Bonifacio, P.; Bellazzini, M.; Caffau, E.;
Ferraro, F.; Marconi, G.; Monaco, L.; Monai, S.; Sbordone, L.
2005nfcd.conf..101Z Altcode: 2005IAUCo.198..101Z
We report on the use of high-resolution spectra to obtain a detailed
description of the Sagittarius dwarf spheroidal internal dynamics,
its Mass and Mass to Light ratio (M/L). Our direct measure of the
central velocity dispersion of SGR give σ<SUB>SGR</SUB>=8.1±0.4
km/s which translates in a total mass estimate of M<SUB>SGR</SUB>
=1.6×10<SUP>8</SUP> M<SUB>⊙</SUB> and corresponding
(M/L)<SUB>SGR</SUB>=9.1 (M/L)<SUB>⊙</SUB>. We also report on a
possible detection of rotation in the core of SGR.
---------------------------------------------------------
Title: λ Bootis stars with composite spectra
Authors: Faraggiana, R.; Bonifacio, P.; Caffau, E.; Gerbaldi, M.;
Nonino, M.
2004A&A...425..615F Altcode: 2004astro.ph..6265F
We examine the large sample of λ Boo candidates collected in Table 1
of Gerbaldi et al. (\cite{Gerbaldi2003}) to see how many of them show
composite spectra. Of the 132 λ Boo candidates we identify 22 which
definitely show composite spectra and 15 more for which there are good
reasons to suspect a composite spectrum. The percentage of λ Boo
candidates with composite spectra is therefore >17% and possibly
considerably higher. For such stars the λ Boo classification should
be reconsidered taking into account the fact that their spectra are
composite. We argue that some of the underabundances reported in the
literature may simply be the result of the failure to consider the
composite nature of the spectra. This leads to the legitimate suspicion
that some, if not all, the λ Boo candidates are not chemically
peculiar at all. A thorough analysis of even a single one of the λ Boo
candidates with composite spectra, in which the composite nature of the
spectrum is duly considered, which would demonstrate that the chemical
peculiarities persist, would clear the doubt we presently have that
the stars with composite spectra may not be λ Boo stars at all. <P
/>Based on observations collected at ESO (Echelec spectrograph) and
at TBL (Telescope Bernard Lyot) of the Pic du Midi Observatory (France).
---------------------------------------------------------
Title: The Sagittarius dwarf galaxy as seen by the VLT/FLAMES facility
Authors: Zaggia, S.; Bonifacio, P.; Bellazzini, M.; Caffau, E.; Di
Marcantonio, P.; Ferraro, F.; Marconi, G.; Monaco, L.; Monai, S.;
Santin, P.; Sbordone, L.
2004MSAIS...5..291Z Altcode:
This is the first report of the use of the VLT FLAMES facility on
the local group dwarf galaxy Sagittarius (SGR). The observing program
aimed at collecting a large sample of high-resolution spectra with two
main goals: (1) to obtain a detailed description of SGR metallicity
distribution, and (2) to study the internal dynamics of SGR, its Mass
and Mass to Light ratio (M/L). With the present work, we confirm
the existence of a metal-rich population, extending above solar
metallicity. The main component of SGR stars is peaked at [Fe/H]∼
-0.5, while we found evidence, for the first time, of a metal-weak tail
in the SGR populations, considerably more metal-weak than M54 ([Fe/H]∼
-1.5). Our direct measure of the central velocity dispersion of SGR
give sigma =8.2±0.3 km s<SUP>-1</SUP> which translates in an M/L=12.5
using current values of the SGR structural parameters. This new value
is in good agreement with the accretion self-consistent “model II”
of \cite{HW01}. <P />Based on Observations collected at the VLT
---------------------------------------------------------
Title: Automatic abundance analysis of high resolution spectra
Authors: Bonifacio, P.; Caffau, E.
2003A&A...399.1183B Altcode: 2002astro.ph.12424B
We describe an automatic procedure for determining abundances from
high resolution spectra. Such procedures are becoming increasingly
important as large amounts of data are delivered from 8 m telescopes
and their high-multiplexing fiber facilities, such as FLAMES on
ESO-VLT. The present procedure is specifically targeted for the
analysis of spectra of giants in the Sgr dSph; however, the procedure
may be, in principle, tailored to analyse stars of any type. Emphasis
is placed on the algorithms and on the stability of the method;
the external accuracy rests, ultimately, on the reliability of the
theoretical models (model-atmospheres, synthetic spectra) used to
interpret the data. Comparison of the results of the procedure with
the results of a traditional analysis for 12 Sgr giants shows that
abundances accurate at the level of 0.2 dex, comparable with that of
traditional analysis of the same spectra, may be derived in a fast
and efficient way. Such automatic procedures are not meant to replace
the traditional abundance analysis, but as an aid to extract rapidly
a good deal of the information contained in the spectra.
---------------------------------------------------------
Title: An astrophysical oscillator strength for the S ii 94.7-nm
resonance line and S abundances in DLAs
Authors: Bonifacio, Piercarlo; Caffau, Elisabetta; Centurión, Miriam;
Molaro, Paolo; Vladilo, Giovanni
2001MNRAS.325..767B Altcode: 2001astro.ph..3234B
By using UV spectra for the O star HD 93521 taken with the ORFEUS
II echelle spectrograph, we determine an `astrophysical' f value
for the Siiλ94.7-nm line: f=0.00498-0.00138+0.00172, error at 1σ
level. This is almost a factor of 30 smaller than the guessed value
found in the Kurucz data base (f=0.1472), which was until now the
only one available for this transition. We use our `astrophysical'
f to investigate the S abundance in two damped Lyα absorption systems
(DLAs) observed with the UV-Visual Echelle Spectrograph (UVES)Q3 at the
European Southern Observatory's 8.2-m Kueyen telescope. In the case
of the absorber at z<SUB>abs</SUB>=3.02486 towards QSO 0347-3819, we
find a sulphur column density which is consistent, within errors, with
that determined by Centurión et al. by means of the λ125.9-nm line,
thus providing an external check on the accuracy of our f value. For
the damped absorber at z<SUB>abs</SUB>=4.4680 towards BR J0307-4945,
we determine a high value of the S abundance, which, however, is
probably the result of blending with Lyα forest lines.
---------------------------------------------------------
Title: Intrinsic colour calibration for F, G, K stars
Authors: Bonifacio, P.; Caffau, E.; Molaro, P.
2000A&AS..145..473B Altcode: 2000astro.ph..6433B
We derive an intrinsic colour calibration for F-K stars using broad band
Johnson colours and line indices KP and HP2. Through this calibration we
can determine E(B-V) of an individual star within 0.03 mag. The E(B-V)
values thus derived are in excellent agreement with those derived from
Strömgren photometry through the Schuster & Nissen (\cite{sch89})
calibration. The agreement is also good with the reddening maps of
Burstein & Heiles (\cite{bur82}) and Schlegel et al. (\cite{sch98}),
although in this case there exists a small offset of about 0.01
mag. This calibration may be applied to the large body of data of the
HK survey extension which will be published in the near future.
---------------------------------------------------------
Title: Photometry of Nova V 1493 Aql
Authors: Bonifacio, P.; Selvelli, P. L.; Caffau, E.
2000A&A...356L..53B Altcode: 2000astro.ph..3156B
We report on photometric observations of V 1493 Aql during the early
decline and highlight some uncommon aspects of the light curve. V
1493 Aql was hotter at maximum light than in the following phases,
and was characterized by the presence of a long lasting secondary
maximum, that, unlike in other novae, was quite red in color. The mean
of three distance estimates yields d ~ 18.8+/- 3.6 Kpc. Such a large
distance would place V 1493 Aql at the extreme outskirts of our Galaxy
or even in an external Local Group galaxy. Based on data collected at
the Osservatorio Astrofisico di Catania, stazione M. G. Fracastoro,
Serra la Nave (Etna), Italia
---------------------------------------------------------
Title: Determination of neutrino incoming direction in the CHOOZ
experiment and its application to supernova explosion location by
scintillator detectors
Authors: Apollonio, M.; Baldini, A.; Bemporad, C.; Caffau, E.; Cei,
F.; Déclais, Y.; de Kerret, H.; Dieterle, B.; Etenko, A.; Foresti, L.;
George, J.; Giannini, G.; Grassi, M.; Kozlov, Y.; Kropp, W.; Kryn, D.;
Laiman, M.; Lane, C. E.; Lefièvre, B.; Machulin, I.; Martemyanov,
A.; Martemyanov, V.; Mikaelyan, L.; Nicolò, D.; Obolensky, M.;
Pazzi, R.; Pieri, G.; Price, L.; Riley, S.; Reeder, R.; Sabelnikov,
A.; Santin, G.; Skorokhvatov, M.; Sobel, H.; Steele, J.; Steinberg,
R.; Sukhotin, S.; Tomshaw, S.; Veron, D.; Vyrodov, V.
1999PhRvD..61a2001A Altcode: 2000PhRvD..61a2001A; 1999hep.ex....6011A
The CHOOZ experiment has measured the antineutrino flux at
about 1 km from two nuclear reactors to search for possible
ν¯<SUB>e</SUB>-->ν¯<SUB>x</SUB> oscillations with mass-squared
differences as low as 10<SUP>-3</SUP> eV<SUP>2</SUP> for full mixing. We
show that the analysis of the ~2700 ν¯<SUB>e</SUB> events, collected
by our liquid scintillation detector, locates the antineutrino source
within a cone of half-aperture ~18° at the 68 % C.L. We discuss the
implications of this result for locating a supernova explosion.
