turck-chieze

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Author name code: turck-chieze
ADS astronomy entries on 2022-09-14
author:"Turck-Chieze, Sylvaine"

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Title: Stellar Atomic Opacities
Authors: Turck-Chiéze, S.
2018ASPC..515....3T Altcode:
Atomic opacities are fundamental ingredients of stellar evolution:
they largely determine the energy transfer inside the stellar interiors
and play crucial roles in the stellar ages and in any thermodynamic
indicator. They are determined by complex atomic calculations performed
for a large range of temperatures and densities and numerous ionic
species. Therefore, their knowledge was for a long time purely
theoretical, and the available tables were the result of different
approaches often used as black boxes. Differences were observed among
them but their origin was not so clear; their resolution has been
stimulated by the development of stellar seismology that scrutinizes
the stellar interiors, and by the hope of astrophysicists to validate
the physics contained in the stellar evolution codes. In the 1990s
the high quality of the measured solar neutrino fluxes and of the
solar acoustic modes encouraged an update of these calculations. At
the same time the first dedicated opacity measurements have also been
performed. During the last decade the asteroseismic space probes (COROT,
KEPLER) have encouraged new comparisons between the theoretical teams
(mainly in France and the USA) and the generation of new tables. Opacity
measurements at the Sandia Laboratory Z facility and promising ones on
high-energy laser facilities (OMEGA, NIF, LMJ) present new challenges
for accurate opacities. This review shows an astrophysicist's point of
view with interesting comparisons and suggestions for new perspectives.

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Title: Progress on a Double Ablation Front Scheme for Iron Spectral
Opacity Measurements in Solar Conditions
Authors: Colaïtis, A.; Ducret, J. -E.; Turck-Chièze, S.; Le Pennec,
M.; Jacquet, L.; Blancard, C.
2018ASPC..515..104C Altcode:
We propose a new method to verify the radiation transport properties
of the plasma at the base of the solar convection zone. The method is
designed for high-power lasers, and exploits the temporal and spatial
stability of hydrodynamic parameters in counter-propagating double
ablation front (DAF) structures. One-dimensional radiative hydrodynamic
simulations of a symmetric DAF structure are studied in the presence of
tracer layers. In this framework an iron sample with electron number
density ne∼ 2×1023 cm-3 can be
taken to an electron temperature of Te∼ 200 eV. These
conditions are obtained for 500 ps with small longitudinal gradients
and with matter very near to local thermodynamical equilibrium. These
results led to an experimental design compatible with the OMEGA laser
of Boehly et al. (1997). We discuss the findings of a preliminary
campaign conducted in 2017.

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Title: Current State of Astrophysical Opacities: A White Paper
Authors: Lynas-Gray, A. E.; Basu, S.; Bautista, M. A.; Colgan, J.;
Mendoza, C.; Tennyson, J.; Trampedach, R.; Turck-Chièze, S.
2018ASPC..515..301L Altcode: 2018arXiv180406804L
Availability of reliable atomic and molecular opacity tables is
essential in a wide variety of astronomical modeling: the solar and
stellar interiors, stellar and planetary atmospheres, stellar evolution,
pulsating stars, and protoplanetary disks, to name a few. With the
advancement of powerful research techniques—such as helioseismology
and asteroseismology, solar neutrino-flux measurements, exoplanet survey
satellites, three-dimensional hydrodynamic atmospheric simulations
(including non-LTE and granulation effects), high-performance computing
of atomic and molecular data, and innovative plasma experiments—the
accuracy and completeness of opacity tables is being taken to an
unprecedented level. The goal of the second Workshop on Astrophysical
Opacities was to gather opacity data producers and consumers from both
the atomic and molecular sectors to contribute to solving outstanding
problems and to develop more effective and integrated interfaces. In
this review we attempt to summarize the discussion at the workshop
and propose future directions for opacity research.

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Title: Workshop on Astrophysical Opacities
Authors: Mendoza, C.; Turck-Chiéze, S.; Colgan, J.
2018ASPC..515....0M Altcode:
No abstract at ADS

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Title: Seismic inversion of the solar entropy. A case for improving
the standard solar model
Authors: Buldgen, G.; Salmon, S. J. A. J.; Noels, A.; Scuflaire, R.;
Reese, D. R.; Dupret, M. -A.; Colgan, J.; Fontes, C. J.; Eggenberger,
P.; Hakel, P.; Kilcrease, D. P.; Turck-Chièze, S.
2017A&A...607A..58B Altcode: 2017arXiv170705138B
Context. The Sun is the most constrained and well-studied of all
stars. As a consequence, the physical ingredients entering solar
models are used as a reference to study all other stars observed in the
Universe. However, our understanding of the solar structure is still
imperfect, as illustrated by the current debate on the heavy element
abundances in the Sun. Aims: We provide additional information
on the solar structure by carrying out structural inversions of a new
physical quantity, a proxy of the entropy of the solar plasma whose
properties are very sensitive to the temperature gradient below the
convective zone. Methods: We use new structural kernels to
carry out direct inversions of an entropy proxy of the solar plasma
and compare the solar structure to various standard solar models built
using various opacity tables and chemical abundances. We also link our
results to classical tests commonly found in the literature. 
Results: Our analysis allows us to probe more efficiently the uncertain
regions of the solar models, just below the convective zone, paving the
way for new in-depth analyses of the Sun taking into account additional
physical uncertainties of solar models beyond the specific question
of chemical abundances.

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Title: Detection of g modes in the asymptotic frequency range:
evidence for a rapidly rotating core
Authors: Ulrich, Roger K.; Fossat, Eric; Boumier, Patrick; Corbard,
Thierry; Provost, Janine; Salabert, David; Schmider, François-Xavier;
Gabriel, Alan; Grec, Gerard; Renaud, Catherine; Robillot, Jean-Maurice;
Roca Cortés, Teodoro; Turck-Chièze, Sylvaine
2017SPD....4810906U Altcode:
We present the identification of very low frequency g modes, in the
asymptotic regime, and two important parameters: the core rotation rate
and the asymptotic equidistant period spacing of these g modes. The
GOLF instrument on the SOHO space observatory has provided two
decades of full disk helioseismic data. The search for g modes in
GOLF measurements has been extremely difficult, due to solar and
instrumental noise. In the present study, the p modes of the GOLF
signal are analyzed differently, searching for possible collective
frequency modulations produced by periodic changes in the deep solar
structure. Such modulations provide access to only very low frequency
g modes, thus allowing statistical methods to take advantage of their
asymptotic properties. For oscillatory periods in the range between 9
and nearly 48 hours, almost 100 g modes of spherical harmonic degree
1 and more than 100 g modes of degree 2 are predicted. They are not
observed individually, but when combined, they unambiguously provide
their asymptotic period equidistance and rotational splittings,
in excellent agreement with the requirements of the asymptotic
approximations. P0, the g-mode period equidistance parameter, is
measured to be 34 min 01 s, with a 1 s uncertainty. The previously
unknown g-mode splittings have now been measured from a non synodic
reference with a very high accuracy, and they imply a mean weighted
rotation of 1277 ± 10 nHz (9-day period) of their kernels, resulting
in a rapid rotation frequency of 1644 ± 23 nHz (period of one week)
of the solar core itself, which is a factor 3:8 ± 0:1 faster than the
rotation of the radiative envelope.Acknowledgements. Ulrich is first
author on this abstract due to AAS rules, Fossat is the actual first
author. SOHO is a project of international collaboration between ESA and
NASA. We would like to acknowledge the support received continuously
during more than 3 decades from CNES. DS acknowledges the financial
support from the CNES GOLF grant and the Observatoire de la Côte
d’Azur for support during his stays. RKU acknowledges support from
NASA for his participation in this project and thanks John Bahcall
for enthusiastic encouragement for the g-mode search.

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Title: Asymptotic g modes: Evidence for a rapid rotation of the
solar core
Authors: Fossat, E.; Boumier, P.; Corbard, T.; Provost, J.; Salabert,
D.; Schmider, F. X.; Gabriel, A. H.; Grec, G.; Renaud, C.; Robillot,
J. M.; Roca-Cortés, T.; Turck-Chièze, S.; Ulrich, R. K.; Lazrek, M.
2017A&A...604A..40F Altcode: 2017arXiv170800259F
Context. Over the past 40 years, helioseismology has been enormously
successful in the study of the solar interior. A shortcoming has
been the lack of a convincing detection of the solar g modes, which
are oscillations driven by gravity and are hidden in the deepest
part of the solar body - its hydrogen-burning core. The detection
of g modes is expected to dramatically improve our ability to model
this core, the rotational characteristics of which have, until now,
remained unknown. Aims: We present the identification of very
low frequency g modes in the asymptotic regime and two important
parameters that have long been waited for: the core rotation rate,
and the asymptotic equidistant period spacing of these g modes. 
Methods: The GOLF instrument on board the SOHO space observatory has
provided two decades of full-disk helioseismic data. The search for
g modes in GOLF measurements has been extremely difficult because of
solar and instrumental noise. In the present study, the p modes of the
GOLF signal are analyzed differently: we search for possible collective
frequency modulations that are produced by periodic changes in the
deep solar structure. Such modulations provide access to only very low
frequency g modes, thus allowing statistical methods to take advantage
of their asymptotic properties. Results: For oscillatory
periods in the range between 9 and nearly 48 h, almost 100 g modes
of spherical harmonic degree 1 and more than 100 g modes of degree 2
are predicted. They are not observed individually, but when combined,
they unambiguously provide their asymptotic period equidistance and
rotational splittings, in excellent agreement with the requirements
of the asymptotic approximations. When the period equidistance has
been measured, all of the individual frequencies of each mode can
be determined. Previously, p-mode helioseismology allowed the g-mode
period equidistance parameter P0 to be bracketed inside a
narrow range, between approximately 34 and 35 min. Here, P0
is measured to be 34 min 01 s, with a 1 s uncertainty. The previously
unknown g-mode splittings have now been measured from a non-synodic
reference with very high accuracy, and they imply a mean weighted
rotation of 1277 ± 10 nHz (9-day period) of their kernels, resulting
in a rapid rotation frequency of 1644 ± 23 nHz (period of one week)
of the solar core itself, which is a factor 3.8 ± 0.1 faster than the
rotation of the radiative envelope. Conclusions: The g modes
are known to be the keys to a better understanding of the structure
and dynamics of the solar core. Their detection with these precise
parameters will certainly stimulate a new era of research in this field.

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Title: Experiment to measure oxygen opacity at high density and
temperature
Authors: Keiter, Paul; Mussack, Katie; Orban, Chris; Colgan, James;
Ducret, Jean-Eric; Fontes, Christopher J.; Guzik, Joyce Ann; Heeter,
Robert F.; Kilcrease, Dave; Le Pennec, Maelle; Mancini, Roberto;
Perry, Ted; Turck-Chièze, Sylvaine; Trantham, Matt
2017AAS...23021317K Altcode:
In recent years, there has been a debate over the abundances of heavy
elements (Z &gt;2) in the solar interior. Recent solar atmosphere models
[Asplund 2009] find a significantly lower abundance for C, N, and O
compared to models used roughly a decade ago. This discrepancy has
led to an investigation of opacities through laboratory experiments
and improved opacity models for many of the larger contributors
to the sun’s opacity, including iron and oxygen. Recent opacity
measurements of iron disagree with opacity model predictions [Bailey
et al, 2015]. Although these results are still controversial, repeated
scrutiny of the experiment and data has not produced a conclusive
reason for the discrepancy. New models have been implemented in the
ATOMIC opacity code for C, O and Fe to address the solar abundance issue
[Colgan, 2013]. Armstrong et al [2014] have also implemented changes in
the ATOMIC code for low-Z elements. However, no data currently exists
to test the low-Z material models in the regime relevant to the solar
convection zone. We present an experimental design using the opacity
platform developed at the National Ignition Facility to study the oxygen
opacity at densities and temperatures near the solar convection zone
conditions.This work is funded by the U.S. DOE, through the NNSA-DS
and SC-OFES Joint Program in HEDPLP, grant No. DE-NA0001840, and the
NLUF Program, grant No. DE-NA0000850, and through LLE, University of
Rochester by the NNSA/OICF under Agreement No. DE-FC52-08NA28302.

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Title: Main results of the PICARD mission
Authors: Meftah, M.; Corbard, T.; Hauchecorne, A.; Irbah, A.; Boumier,
P.; Chevalier, A.; Schmutz, W.; Ikhlef, R.; Morand, F.; Renaud, C.;
Hochedez, J. -F.; Cessateur, G.; Turck-Chièze, S.; Salabert, D.;
Rouzé, M.; van Ruymbeke, M.; Zhu, P.; Kholikov, S.; Koller, S.;
Conscience, C.; Dewitte, S.; Damé, L.; Djafer, D.
2016SPIE.9904E..0ZM Altcode:
PICARD is a mission devoted to solar variability observations through
imagery and radiometric measurements. The main goal is to provide data
for scientific investigation first in the area of solar physics, and
second in the assessment of the influence of the solar variability on
the Earth climate variability. PICARD contains a double program with
in-space and on-ground measurements. The PICARD spacecraft was launched
on June 15, 2010, commissioned in-flight in October of the same year
and was retired in April 2014. The PICARD ground-based observatory is
operational since May 2011. We shall give a short overview of the PICARD
instrumentation. New estimates of the absolute values of the total solar
irradiance, of the solar spectral irradiance at typical wavelengths,
and of the solar oblateness will be given. We will also report about
helioseismic studies. Finally, we will present our current results
about solar radius variations after six years of solar observation.

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Title: On the Current Solar Magnetic Activity using Its Behavior
During the Holocene
Authors: Inceoglu, Fadil; Simoniello, Rosaria; Faurschou Knudsen,
Mads; Karoff, Christoffer; Olsen, Jesper; Turck-Chieze, Sylvaine
2016cosp...41E.862I Altcode:
Solar modulation potential (SMP) reconstructions based on cosmogenic
nuclide records reflect changes in the open solar magnetic field and
can therefore help us obtain information on the behavior of the open
solar magnetic field over the Holocene period. Using the Greenland
Ice Core Project (GRIP) ^{10}Be and IntCal13 ^{14}C records for the
overlapping time period spanning between ∼1650 AD to 6600 BC, we
first reconstructed the solar modulation potentials and subsequently
investigate the statistics of peaks and dips simultaneously occurring in
the two SMP reconstructions. Based on the distribution of these events,
we propose a method to identify grand minima and maxima periods. We then
aim at comparing the Sun's large-scale magnetic field behavior over
the last three solar cycles with variations in the SMP reconstruction
through the Holocene epoch. To achieve these objectives, we use the
IntCal13 ^{14}C data to investigate distinct patterns in the occurrences
of grand minima and maxima during the Holocene period. We then check
whether these patterns might mimic the recent solar magnetic activity
by investigating the evolution of the energy in the Sun's large-scale
dipolar magnetic field using the Wilcox Solar Observatory data. The
cosmogenic radionuclide data analysis shows that ∼71 % of grand
maxima during the period from 6600 BC to 1650 AD were followed by a
grand minimum. The characteristics of the occurrences of grand maxima
and minima are consistent with the scenario in which the dynamical
non-linearity induced by the Lorentz force leads the Sun to act as a
relaxation oscillator. This finding implies that the probability for
these events to occur is non-uniformly distributed in time, as there
is a memory in their driving mechanism, which can be identified via
the back-reaction of the Lorentz force.

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Title: Detailed Opacity Comparison for an Improved Stellar Modeling
of the Envelopes of Massive Stars
Authors: Turck-Chièze, S.; Le Pennec, M.; Ducret, J. E.; Colgan, J.;
Kilcrease, D. P.; Fontes, C. J.; Magee, N.; Gilleron, F.; Pain, J. C.
2016ApJ...823...78T Altcode:
Seismic observations have led to doubts or ambiguities concerning the
opacity calculations used in stellar physics. Here, we concentrate
on the iron-group opacity peak, due to iron, nickel, and chromium,
located around T = 200,000 K for densities from {10}-8
{to} {10}-4 {{g}} {{cm}}-3, which creates some
convective layers in stellar radiative envelopes for masses between 3
and 18 {M}⊙ . These conditions were extensively studied
in the 1980s. More recently, inconsistencies between OP and OPAL
opacity calculations have complicated the interpretation of seismic
observations as the iron-group opacity peak excites acoustic and gravity
modes in SPB, β Cephei, and sdB stars. We investigate the reliability
of the theoretical opacity calculations using the modern opacity codes
ATOMIC and SCO-RCG. We show their temperature and density dependence
for conditions that are achievable in the laboratory and equivalent
to astrophysical conditions. We also compare new theoretical opacity
spectra with OP spectra and quantify how different approximations
impact the Rosseland mean calculations.This detailed study estimates new
ATOMIC and SCO-RCG Rosseland mean values for astrophysical conditions
which we compare to OP values. Some puzzling questions are still under
investigation for iron, but we find a strong increase in the Rosseland
mean nickel opacity of a factor between 2 and 6 compared to OP. This
appears to be due to the use of extrapolated atomic data for the Ni
opacity within the OP calculations. A study on chromium is also shown.

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Title: The Standard Solar Model and beyond
Authors: Turck-Chièze, S.
2016JPhCS.665a2078T Altcode:
The Standard Solar Model (SSM) is an important reference in Astrophysics
as the Sun stays today the most observed star. This model is used to
predict the internal observables like neutrino fluxes and oscillation
frequencies and consequently to validate its assumptions for its
generalization to other stars. The model outputs result from the
resolution of the classical stellar equations and the knowledge of
fundamental physics like nuclear reaction rates, screening, photon
interaction, plasma physics. The plasma conditions remained unmeasurable
in laboratory for long due to the high temperature and high density
conditions of the solar interior. Today, neutrino detections and
helioseismology aboard SoHO have largely revealed the solar interior, in
particular the nuclear solar core so one can estimate the reliability
of SSM and also its coherence with the different indicators and
between them. This has been possible thanks to a Seismic Solar Model
(SeSM) which takes into account in addition the observed sound speed
profile. Seismology quantifies also some internal dynamical processes
that need to be properly introduced in the description of stars. This
review describes the different steps of building of the SSM, its
predictions and the comparisons with observations. It discusses the
accuracy of such model compared to the accuracy of the SeSM. The
noticed differences and observational constraints put some limits on
other possible processes like dark matter, magnetic field or waves
and determine the directions of progress for the near future that
will come from precise emitted neutrino fluxes. High density laser
facilities promise also unprecedented checks of energy transfer by
photons and nuclear reaction rates.

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Title: On the Current Solar Magnetic Activity in the Light of Its
Behaviour During the Holocene
Authors: Inceoglu, F.; Simoniello, R.; Knudsen, M. F.; Karoff, C.;
Olsen, J.; Turck-Chièze, S.
2016SoPh..291..303I Altcode: 2015arXiv150906182I; 2015SoPh..tmp..159I
Solar modulation potential (SMP) reconstructions based on cosmogenic
nuclide records reflect changes in the open solar magnetic field and
can therefore help us obtain information on the behaviour of the open
solar magnetic field over the Holocene period. We aim at comparing the
Sun's large-scale magnetic field behaviour over the last three solar
cycles with variations in the SMP reconstruction through the Holocene
epoch. To achieve these objectives, we use the IntCal13 14C
data to investigate distinct patterns in the occurrences of grand
minima and maxima during the Holocene period. We then check whether
these patterns might mimic the recent solar magnetic activity by
investigating the evolution of the energy in the Sun's large-scale
dipolar magnetic field using the Wilcox Solar Observatory data. The
cosmogenic radionuclide data analysis shows that ≈71 % of grand
maxima during the period from 6600 BC to 1650 AD were followed by a
grand minimum. The characteristics of the occurrences of grand maxima
and minima are consistent with the scenario in which the dynamical
non-linearity induced by the Lorentz force leads the Sun to act as a
relaxation oscillator. This finding implies that the probability for
these events to occur is non-uniformly distributed in time, as there
is a memory in their driving mechanism, which can be identified via
the back-reaction of the Lorentz force.

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Title: Understanding the Internal Chemical Composition and Physical
Processes of the Solar Interior
Authors: Basu, Sarbani; Grevesse, Nicolas; Mathis, Stephane;
Turck-Chièze, Sylvaine
2015SSRv..196...49B Altcode: 2014SSRv..tmp....3B
The Sun, the closest and most well studied of stars, is generally used
as a standard that other stars are compared to. Models of the Sun are
constantly tested with helioseismic data. These data allow us to probe
the internal structure and dynamics of the Sun. Among the main sources
of the data is the SOHO spacecraft that has been continuously observing
the Sun for more than a solar cycle. Current solar models, although
good, do not include all the physical processes that are present in the
Sun. In this chapter we focus on specific inputs to solar models and
discuss generally neglected dynamical physical processes whose inclusion
could result in models that are much better representatives of the Sun.

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Title: New opacity measurement principle for LMJ-PETAL laser facility
Authors: Le Pennec, M.; Ribeyre, X.; Ducret, J. -E.; Turck-Chièze, S.
2015HEDP...17..162L Altcode: 2015arXiv150903563L
Stellar seismology reveals some interior properties of thousands of
solar-type stars but the solar seismic sound speed stays puzzling
since a decade as it disagrees with the Standard Solar Model (SSM)
prediction. One of the explanations of this disagreement may be found
in the treatment of the transport of radiation from the solar core
to the surface. As the same framework is used for other stars, it is
important to check precisely the reliability of the interacting cross
sections of photons with each species in order to ensure the energy
transport for temperature T &gt; 2-106 K and density ρ
&gt; 0.2 g/cm3. In this paper, we propose a new technique to
reach the domain of temperature and density found in the solar radiative
interior. This technique called the Double Ablation Front (DAF) is based
on a high conversion of the laser energy into X-rays thanks to moderated
Z material irradiated by laser intensity between 1.5 × 1015
W/cm2 and 4 × 1015 W/cm2. This high
conversion creates, in addition to the electronic front a second
ablation front in the moderated Z material. Between the two fronts
there is a plateau of density and temperature that we exploit to heat
a sample of iron or of oxide. The first simulations realized with
the hydrodynamic code CHIC show that this technique allows to reach
conditions equivalent to half the radiative zone of the Sun with high
stability both in time and space. We examine the possibility to measure
both iron and oxygen absorption spectra.

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Title: Asteroseismic hare &amp; hound exercises: the case of β
Cephei stars
Authors: Salmon, S. J. A. J.; Montalbán, J.; Miglio, A.; Noels, A.;
Dupret, M. -A.; Eggenberger, P.; Turck-Chièze, S.
2015sf2a.conf..423S Altcode:
The β Cephei pulsating stars present a unique opportunity to test and
probe our knowledge of the interior of massive stars. The information
that we can get depends on the quality and number of observational
constraints, both seismic and classical ones. The asteroseismology
of β Cephei stars proceeds by a forward approach, which can result
in multiple solutions, without clear indication on the level of
confidence. We seek a method to derive confidence intervals on
stellar parameters and investigate how these latter behave depending
on the seismic data accessible to the observer. We realise forward
modelling with the help of a grid of pre-computed models. We also
use Monte-Carlo simulations to build confidence intervals on the
inferred stellar parameters. We apply and test this method in a
series of hare and hound exercises on a subset of theoretical models
simulating observed stars. Results show that a set of 5 frequencies
(with knowledge of their associated angular degree) yields precise
seismic constraints. Significant errors on the determination of the
extent of the central mixed region may result when the theoretical
models do not present the same chemical mixture as the observed star.

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Title: Future Mission Concepts for Helioseismology
Authors: Sekii, Takashi; Appourchaux, Thierry; Fleck, Bernhard;
Turck-Chièze, Sylvaine
2015SSRv..196..285S Altcode: 2015SSRv..tmp...15S
Future space-mission concepts currently discussed in the helioseismology
community are reviewed. One popular idea is to observe the Sun from high
latitudes, to explore the polar regions as well as to probe the deep
interior using stereoscopic techniques, by combining observations from
high latitudes with observations from within the ecliptic plane. Another
idea is to stay within the ecliptic plane but still aim for stereoscopic
helioseismology for deep layers. A new instrument and a novel mission
concept for studying the solar core regions are also discussed.

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Title: First New Solar Models with OPAS Opacity Tables
Authors: Le Pennec, M.; Turck-Chièze, S.; Salmon, S.; Blancard, C.;
Cossé, P.; Faussurier, G.; Mondet, G.
2015ApJ...813L..42L Altcode: 2015arXiv151005600L
Stellar seismology appears more and more as a powerful tool
for a better determination of the fundamental properties of
solar-type stars. However, the particular case of the Sun is still
challenging. For about a decade now, the helioseismic sound-speed
determination has continued to disagree with the standard solar model
(SSM) prediction, questioning the reliability of this model. One of the
sources of uncertainty could be in the treatment of the transport of
radiation from the solar core to the surface. In this Letter, we use
the new OPAS opacity tables, recently available for solar modeling,
to address this issue. We discuss first the peculiarities of these
tables, then we quantify their impact on the solar sound-speed and
density profiles using the reduced OPAS tables taken on the grids of
the OPAL ones. We use the two evolution codes, Modules for Experiments
in Stellar Astrophysics and Code Liégeois d’Evolution Stellaire,
that led to similar conclusions in the solar radiative zone. In
comparison to commonly used OPAL opacity tables, the new solar models
are computed for the most recent photospheric composition with OPAS
tables and present improvements to the location of the base of the
convective zone and to the description of the solar radiative zone in
comparison to the helioseismic observations, even if the differences
in the Rosseland mean opacity do not exceed 6%. We finally carry out
a comparison to a solar model computed with the OP opacity tables.

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Title: Testing stellar opacities with laser facilities
Authors: Le Pennec, Maëlle; TURCK-CHIEZE, Sylvaine; RIBEYRE, Xavier;
DUCRET, Jean-Eric; SALMON, Sébastien; BLANCARD, Christophe; COSSE,
Philippe; MONDET, Guillaume; FAUSSURIER, Gérald; CONSORTIUM, OPAC
2015IAUGA..2255164L Altcode:
Helio and asteroseismology (SoHo, KEPLER...) have produced observed
acoustic oscillations of thousands of stars which characteristics are
deeply linked to the transport of radiation inside the stars. However,
the comparisons of seismic data with model predictions have led to
significant discrepancies, which could be due to a bad knowledge of
production and transport of energy.β-Cephei are pulsating stars,
progenitor of supernovae and thus deeply linked to our understanding
of stellar medium enrichment. Their study has shown some difficulty
to predict the observed oscillation modes, which are directly linked
to an opacity bump of the elements of the iron group (Cr, Fe, Ni)
at log T=5.25 (κ-mechanism). We will show that several parameters
of the stars (mass, age, metallicity) have a great influence on the
amplitude of the bump, which impact their structure. We will then
present the final results of an experiment conducted at LULI 2000 in
2011 on Cr, Fe and Ni compared to several opacity codes. We will show
how to improve the opacity in the range of temperature around log T=
5.3.The Sun is a privilege place to test and validate physics. Since
the recent update of the solar composition, there is a well established
large discrepancy (Turck-Chièze et al. 2001) between solar models and
seismic data, visible on the solar sound speed profile comparison.An
explanation could be that the calculations of energy transport are
not correctly taken into account.Unfortunately, there are very few
experiments to validate these calculations (Bailey et al. 2014). That's
why we are proposing an opacity experiment on a high-energy laser like
LMJ, in the conditions of the radiative zone. We are exploiting in that
purpose an approach called the Double Ablation Front to reach these high
temperatures and densities at LTE and validate or not plasma effects
and line widths. We will show the principle of this technique and
the results of our simulations on several elements.In the mean time,
we are also exploiting new opacity calculations thanks to the OPAS
code (Blancard et al. 2012) at the conditions of the solar radiative
zone. We will show the impact of these calculations on the solar model.

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Title: Validating solar and solar-like star opacities
Authors: Le Pennec, Maëlle; TURCK-CHIEZE, Sylvaine; RIBEYRE, Xavier;
DUCRET, Jean-Eric; BLANCARD, Christophe; COSSE, Philippe; MONDET,
Guillaume; FAUSSURIER, Gérald
2015IAUGA..2255142L Altcode:
The Sun is, as being our closest star, a privilege place to test and
validate physics. However, the solar physics is not yet completely
understood. Indeed, since the recent update of the solar composition,
there are differences between solar models and seismic data,
visible on the solar sound speed profile comparison. This well
established large discrepancy (Turck-Chièze et al. 2001, 2004,
2011, Christensen-Dalsgaard et al. 2009, Basu et al. 2015) could be
linked to radiative transfer issue.Two directions of investigation
are proposed. One possibility to explain this gap could be that the
Sun produces slightly more energy that it liberates on its surface
(around 5%). This energy could be transformed into macroscopic motions
in the radiative zone, which are not taken into account in the solar
standard model. Another explanation could be that the calculations of
energy transport are not correctly taken into account either on the
calculation of the Rosseland mean values or in the treatment of the
radiative acceleration. This could have an impact on the determination
of the internal solar abundances.Unfortunately, there are very few
experiments to validate these calculations (Bailey et al. 2014). That's
why we are proposing an opacity experiment on a high-energy laser like
LMJ, in the conditions of the radiative zone (T=[2 - 15.106
K] and ρ=[0.2 - 150 g/cm3]). The aim is to measure the
opacity of the most important contributors to the global opacity in
this solar area : iron, oxygen and silicon. We are exploiting in that
purpose a technical approach called the Double Ablation Front. During
the laser-plasma interaction, the plasma radiative effects allow to
reach these high temperatures and densities at LTE and validate or not
plasma effects and line widths. We will show the principle of this
technique and the results of our simulations on several elements.In
the mean time, we are also exploiting new opacity calculations thanks
to the OPAS code (Blancard et al. 2012) at the conditions of the solar
radiative zone. We will show the impact of these calculations on the
solar model.

---------------------------------------------------------
Title: Opacities in the massive stellar envelopes
Authors: Le Pennec, Maëlle; TURCK-CHIEZE, Sylvaine; SALMON,
Sébastien; CONSORTIUM, OPAC
2015IAUGA..2255248L Altcode:
Helio and asteroseismology (SoHo, CoRoT, KEPLER...) have produced
observed acoustic oscillations of thousands of stars. The
characteristics of these oscillations are deeply linked to the
transport of radiation inside the stars. However, the comparisons
of seismic data of Sun and stars with model predictions have led to
significant discrepancies, which could be due to a bad knowledge of
production and transport of energy.We will focus here on the case of
β-Cephei.β-Cephei are pulsating stars, progenitor of supernovae
and thus deeply linked to our understanding of stellar medium
enrichment. Their study has shown some difficulty to predict the
observed oscillation modes, which are directly linked to a bump of the
opacity of the elements of the iron group (Cr, Fe, Ni) at log T=5.25
through their pulsating mechanism called the κ-mechanism. We will show
that the different parameters of the stars (mass, age, metallicity)
have a great influence on the amplitude of the bump, and then on the
structure of the considered star.The mastery of the κ-mechanism that
produces the pulsation of these stars supposes a fine determination of
the peak opacity of the iron group in their envelope. We will present
the final results of an experiment conducted at LULI 2000 in 2011 on Cr,
Fe and Ni and compare them to OP and ATOMIC, SCO-RCG codes. We will
show how to improve the opacity in the range of temperature around
log T= 5.3.

---------------------------------------------------------
Title: Seismic sensitivity to sub-surface solar activity from 18 yr
of GOLF/SoHO observations
Authors: Salabert, D.; García, R. A.; Turck-Chièze, S.
2015A&A...578A.137S Altcode: 2015arXiv150207607S
Solar activity has significantly changed over the last two Schwabe
cycles. After a long and deep minimum at the end of Cycle 23, the
weaker activity of Cycle 24 contrasts with the previous cycles. In
this work, the response of the solar acoustic oscillations to solar
activity is used in order to provide insights into the structural
and magnetic changes in the sub-surface layers of the Sun during
this on-going unusual period of low activity. We analyze 18 yr of
continuous observations of the solar acoustic oscillations collected
by the Sun-as-a-star GOLF instrument on board the SoHO spacecraft. From
the fitted mode frequencies, the temporal variability of the frequency
shifts of the radial, dipolar, and quadrupolar modes are studied
for different frequency ranges that are sensitive to different
layers in the solar sub-surface interior. The low-frequency modes
show nearly unchanged frequency shifts between Cycles 23 and 24,
with a time evolving signature of the quasi-biennial oscillation,
which is particularly visible for the quadrupole component revealing
the presence of a complex magnetic structure. The modes at higher
frequencies show frequency shifts that are 30% smaller during Cycle
24, which is in agreement with the decrease observed in the surface
activity between Cycles 23 and 24. The analysis of 18 yr of GOLF
oscillations indicates that the structural and magnetic changes
responsible for the frequency shifts remained comparable between
Cycle 23 and Cycle 24 in the deeper sub-surface layers below
1400 km as revealed by the low-frequency modes. The frequency
shifts of the higher-frequency modes, sensitive to shallower
regions, show that Cycle 24 is magnetically weaker in the upper
layers of Sun. Appendices are available in electronic form at <A
href="http://www.aanda.org/10.1051/0004-6361/201425236/olm">http://www.aanda.org</A>The
following 68 GOLF frequency tables are available and Table
A.1 is 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/578/A137">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/578/A137</A>

---------------------------------------------------------
Title: Grand solar minima and maxima deduced from 10Be and
14C: magnetic dynamo configuration and polarity reversal
Authors: Inceoglu, F.; Simoniello, R.; Knudsen, M. F.; Karoff, C.;
Olsen, J.; Turck-Chiéze, S.; Jacobsen, B. H.
2015A&A...577A..20I Altcode:
 Aims: This study aims to improve our understanding of the
occurrence and origin of grand solar maxima and minima. Methods:
We first investigate the statistics of peaks and dips simultaneously
occurring in the solar modulation potentials reconstructed using
the Greenland Ice Core Project (GRIP) 10Be and IntCal13
14C records for the overlapping time period spanning between
~1650 AD to 6600 BC. Based on the distribution of these events, we
propose a method to identify grand minima and maxima periods. By using
waiting time distribution analysis, we investigate the nature of grand
minima and maxima periods identified based on the criteria as well
as the variance and significance of the Hale cycle during these kinds
of events throughout the Holocene epoch. Results: Analysis of
grand minima and maxima events occurring simultaneously in the solar
modulation potentials, reconstructed based on the 14C and the
10Be records, shows that the majority of events characterized
by periods of moderate activity levels tend to last less than 50 years:
grand maxima periods do not last longer than 100 years, while grand
minima can persist slightly longer. The power and the variance of the
22-year Hale cycle increases during grand maxima and decreases during
grand minima, compared to periods characterized by moderate activity
levels. Conclusions: We present the first reconstruction of
the occurrence of grand solar maxima and minima during the Holocene
based on simultaneous changes in records of past solar variability
derived from tree-ring 14C and ice-core 10Be,
respectively. This robust determination of the occurrence of grand solar
minima and maxima periods will enable systematic investigations of the
influence of grand solar minima and maxima episodes on Earth's climate.

---------------------------------------------------------
Title: On the Determination and Constancy of the Solar Oblateness
Authors: Meftah, M.; Irbah, A.; Hauchecorne, A.; Corbard, T.;
Turck-Chièze, S.; Hochedez, J. -F.; Boumier, P.; Chevalier, A.;
Dewitte, S.; Mekaoui, S.; Salabert, D.
2015SoPh..290..673M Altcode: 2015SoPh..tmp...22M
The equator-to-pole radius difference
(Δr=Req−Rpol) is a fundamental property of
our star, and understanding it will enrich future solar and stellar
dynamical models. The solar oblateness (Δ⊙) corresponds
to the excess ratio of the equatorial solar radius (Req)
to the polar radius (Rpol), which is of great interest for
those working in relativity and different areas of solar physics. Δr
is known to be a rather small quantity, where a positive value of
about 8 milli-arcseconds (mas) is suggested by previous measurements
and predictions. The Picard space mission aimed to measure Δr with a
precision better than 0.5 mas. The Solar Diameter Imager and Surface
Mapper (SODISM) onboard Picard was a Ritchey-Chrétien telescope that
took images of the Sun at several wavelengths. The SODISM measurements
of the solar shape were obtained during special roll maneuvers of the
spacecraft by 30° steps. They have produced precise determinations of
the solar oblateness at 782.2 nm. After correcting measurements for
optical distortion and for instrument temperature trend, we found a
solar equator-to-pole radius difference at 782.2 nm of 7.9±0.3 mas
(5.7±0.2 km) at one σ. This measurement has been repeated several
times during the first year of the space-borne observations, and we
have not observed any correlation between oblateness and total solar
irradiance variations.

---------------------------------------------------------
Title: VizieR Online Data Catalog: Solar acoustic modes in period
1996-2014 (Salabert+, 2015)
Authors: Salabert, D.; Garcia, R. A.; Turck-Chieze, S.
2015yCat..35780137S Altcode:
The central frequencies of the l = 0, 1, 2, and 3 acoustic modes of
oscillations of the Sun between 1500{micro}Hz and 4000{micro}Hz and
their associated formal 1σ uncertainties extracted from 365-day
subseries of 18 years of the space-based, Sun-as-a-star GOLF/SoHO
observations between 1996 April 11, and 2014 March 5 are presented. As
a four-time overlap of 91.25 days was used, a total of 69 frequency
tables are provided. We note that one of every four frequency tables
contains frequencies extracted from independent subseries. Quality
criteria were defined based on the fitted mode parameters and their
associated uncertainties in order to remove outliers. An info file
containing the associated starting date and duty cycle of each 365-day
subseries is also provided. The corresponding mean 10.7cm radio flux
is also given in the info file. (2 data files).

---------------------------------------------------------
Title: Stellar opacity validations
Authors: Le Pennec, M.; Turck-Chièze, S.; Ribeyre, X.; Ducret, J. E.
2014sf2a.conf..487L Altcode:
This paper focuses on the radiative transfer in stars where opacities
seem to raise problems : β-Cephei and solar-type stars. We first
concentrate on the iron bump (log T = 5.25), responsible for β-Cephei
pulsations through the κ-mechanism. To discriminate between the
different opacity calculations used to predict their oscillations, new
well-qualified calculations are used and compared to OP calculations. In
parallel with this theoretical work, an experiment has been conducted at
LULI 2000 in 2011 on iron and nickel. We show that this extended study
pushes for the revision of the tables in the conditions corresponding
to the iron bump region, at least for nickel. We will then deal with
the Sun case for which we are preparing an opacity experiment on
a high-energy laser, in some conditions of the radiative zone (T =
[2 - 15 ×10^{6} K] and ρ = [0.2 - 150 g/cm^{3}]). To reach these
high temperatures and densities at LTE and validate or not plasma
effects and line widths, we are exploring an approach called the Double
Ablation Front, driven by plasma radiative effects. The 1D simulations
performed with the code CHIC show that with this technique, we could
reach conditions equivalent to the conditions of half of the solar
radiative zone.

---------------------------------------------------------
Title: Detecting Gravity Modes in the Solar 8 B Neutrino
Flux
Authors: Lopes, Ilídio; Turck-Chièze, Sylvaine
2014ApJ...792L..35L Altcode: 2014arXiv1408.6671L
The detection of gravity modes produced in the solar radiative zone
has been a challenge in modern astrophysics for more than 30 yr and
their amplitude in the core is not yet determined. In this Letter,
we develop a new strategy to look for standing gravity modes through
solar neutrino fluxes. We note that due to a resonance effect, the
gravity modes of low degree and low order have the largest impact on
the 8 B neutrino flux. The strongest effect is expected
to occur for the dipole mode with radial order 2, corresponding
to periods of about 1.5 hr. These standing gravity waves produce
temperature fluctuations that are amplified by a factor of 170 in the
boron neutrino flux for the corresponding period, in consonance with
the gravity modes. From current neutrino observations, we determine
that the maximum temperature variation due to the gravity modes in
the Sun's core is smaller than 5.8 × 10-4. This study
clearly shows that due to their high sensitivity to the temperature,
the 8 B neutrino flux time series is an excellent tool to
determine the properties of gravity modes in the solar core. Moreover,
if gravity mode footprints are discovered in the 8 B neutrino
flux, this opens a new line of research to probe the physics of the
solar core as non-standing gravity waves of higher periods cannot be
directly detected by helioseismology but could leave their signature
on boron neutrino or on other neutrino fluxes.

---------------------------------------------------------
Title: Picard SODISM, a Space Telescope to Study the Sun from the
Middle Ultraviolet to the Near Infrared
Authors: Meftah, M.; Hochedez, J. -F.; Irbah, A.; Hauchecorne, A.;
Boumier, P.; Corbard, T.; Turck-Chièze, S.; Abbaki, S.; Assus,
P.; Bertran, E.; Bourget, P.; Buisson, F.; Chaigneau, M.; Damé,
L.; Djafer, D.; Dufour, C.; Etcheto, P.; Ferrero, P.; Hersé, M.;
Marcovici, J. -P.; Meissonnier, M.; Morand, F.; Poiet, G.; Prado,
J. -Y.; Renaud, C.; Rouanet, N.; Rouzé, M.; Salabert, D.; Vieau,
A. -J.
2014SoPh..289.1043M Altcode: 2013arXiv1303.0731M
The Solar Diameter Imager and Surface Mapper (SODISM) onboard the
Picard space mission provides wide-field images of the photosphere
and chromosphere of the Sun in five narrow bandpasses centered at
215.0, 393.37, 535.7, 607.1, and 782.2 nm. The Picard spacecraft
was successfully launched on 15 June 2010 into a Sun-synchronous
dawn-dusk orbit. The Picard space mission represents a European asset
in collecting solar observations useful to improve Earth climatic
models. The scientific payload consists of the SODISM imager and
of two radiometers, SOlar VAriability Picard (SOVAP) and PREcision
MOnitor Sensor (PREMOS), which measure the Total Solar Irradiance
(TSI) and part of the Solar Spectral Irradiance (SSI).

---------------------------------------------------------
Title: Iron-group opacities in the envelopes of massive stars
Authors: Le Pennec, Maëlle; Turck-Chièze, Sylvaine
2014IAUS..301..229L Altcode:
β Cephei and SPB stars are pulsating stars for which the excitation of
modes by the κ mechanism, due to the iron-group opacity peak, seems
puzzling. We have first investigated the origins of the differences
noticed between OP and OPAL iron and nickel opacity calculations (up to
a factor 2), a fact which complicates the interpretation. To accomplish
this task, new well-qualified calculations (SCO-RCG, HULLAC and ATOMIC)
have been performed and compared to values of these tables, and most
of the differences are now well understood. Next, we have exploited a
dedicated experiment on chromium, iron and nickel, conducted at the
LULI 2000 facilities. We found that, in the case of iron, detailed
calculations (OP, ATOMIC and HULLAC) show good agreement, contrary to
all of the non-detailed calculations. However, in the case of nickel,
OP calculations show large discrepancies with the experiments but
also with other codes. Thus, the opacity tables need to be revised
in the thermodynamical conditions corresponding to the peak of the
iron group. Consequently we study the evolution of this iron peak
with changes in stellar mass, age, and metallicity to determine the
relevant region where these tables should be revised.

---------------------------------------------------------
Title: Models of solar surface dynamics: impact on eigenfrequencies
and radius
Authors: Piau, L.; Collet, R.; Stein, R. F.; Trampedach, R.; Morel,
P.; Turck-Chièze, S.
2014MNRAS.437..164P Altcode: 2013arXiv1309.7179P; 2013MNRAS.tmp.2547P
We study the effects of different descriptions of the solar surface
convection on the eigenfrequencies of p modes. 1D evolution calculations
of the whole Sun and 3D hydrodynamic and magnetohydrodynamic simulations
of the current surface are performed. These calculations rely on
realistic physics. Averaged stratifications of the 3D simulations are
introduced in the 1D solar evolution or in the structure models. The
eigenfrequencies obtained are compared to those of 1D models relying
on the usual phenomenologies of convection and to observations of the
Michelson Doppler Imager instrument aboard the Solar Heliospheric
Observatory (SoHO). We also investigate how the magnetic activity
could change the eigenfrequencies and the solar radius, assuming that,
3 Mm below the surface, the upgoing plasma advects a 1.2 kG horizontal
field. All models and observed eigenfrequencies are fairly close below 3
mHz. Above 3 mHz the eigenfrequencies of the phenomenological convection
models are above the observed eigenfrequencies. The frequencies
of the models based on the 3D simulations are slightly below the
observed frequencies. Their maximum deviation is ≈3 μHz at 3 mHz
but drops below 1 μHz at 4 mHz. Replacing the hydrodynamic by the
magnetohydrodynamic simulation increases the eigenfrequencies. The shift
is negligible below 2.2 mHz and then increases linearly with frequency
to reach ≈1.7 μHz at 4 mHz. The impact of the simulated activity
is a 14 mas shrinking of the solar layers near the optical depth unity.

---------------------------------------------------------
Title: Are We Entering a Period of Reduced Activity or a Grand
Minima State?
Authors: Simoniello, R.; Jain, K.; Tripathy, S. C.; Baldner, C. S.;
Turck-Chièze, S.; Hill, F.
2013ASPC..478..167S Altcode:
Solar cycle 23 has been characterized by an unpredicted deepest
minimum in nearly a century, and solar cycle 24 has turned out to be
20% less strong than the previous cycle, against expectations. Are
the current solar dynamics indicative that we might enter a period
of reduced activity or even a Grand Minima state? To answer this
question, we investigated the properties of the cyclic behavior
of solar magnetic activity, characterized by the 11- and 2-year
periodicity, the latter also known as the quasi-biennial periodicity
(QBP). Recently it has been shown that the QBP signal might be the
cycle period related to the quadrupolar component of the magnetic
dynamo configuration. Observationally and theoretically, it has been
shown that this component might play a key role over period of reduced
activity by inducing a strong North-South asymmetry. We, therefore,
wonder if the QBP signatures might be used as a precursor of solar
magnetic activity. To this aim we used 17 years of Global Oscillation
Network Group (GONG) observations to investigate the signatures and
properties of the QBP in the dipolar and quadrupolar component of
p-mode frequency shifts and in the even-order splitting coefficients
of spherical degree ℓ = 0 - 120, as the latter are related to the
magnetic field strength and oblateness. The observational findings
seem to indicate that the QBP signal strength has been particularly
strong over the ascending phase of solar cycle 23, but suddenly in
2003 became weaker and has remained weak over the ascending phase of
solar cycle 24. We argue that the QBP, since 2003, suggested a week
solar cycle 24 compared to cycle 23.

---------------------------------------------------------
Title: The Energetic Balance of the Sun and Stars
Authors: Turck-Chièze, S.; Couvidat, S.; Gilles, D.; Le Pennec, M.
2013ASPC..479..485T Altcode:
Helio- and asteroseismology keep delivering unprecedented views on
solar and stellar interiors that were not anticipated twenty years
ago. After five decades of detailed measurements, it is interesting
to question the classical stellar evolution models in the light of
these observations. This report focuses on two important aspects of
stellar evolution: the conservation of energy and the transfer of
energy in radiative zones. We discuss the reliability of the opacity
coefficients provided by Opacity Project (OP) and OPAL tables by
creating a stellar plasma in a laboratory and using new computer
capabilities to perform more complex calculations. We then discuss the
reliability of the energetic balance in solar-like stars in the light
of both helioseismology and neutrino detections. We cannot exclude
the possibility that a more detailed balance might be considered that
takes into account the action of dynamical phenomena like meridional
circulation, a fossil magnetic field generated during the initial
stellar contraction or gravity waves along the Main Sequence phase.

---------------------------------------------------------
Title: Probing the radiative zones of stars: Present status and
developments
Authors: Turck-Chièze, S.
2013EAS....63..339T Altcode:
Seismology of Sun and stars associated to precise solar neutrino
detections reveals microscopic and macroscopic behaviors of radiative
zones that were not anticipated by stellar modeling predictions. These
results allow us to check the hypotheses of the equations used in
stellar evolution for long. In this review, I list some of the problems
which emerge from these confrontations both on the description of
the Sun or solar-like stars and on the envelopes of intermediate-type
stars, then I summarize the cases at least partly solved in using 3D MHD
simulations, new opacity calculations and laboratory experiments. This
review shows also how we hope to progress on the others inside our
OPAC consortium or in using the coming detection of neutrino fluxes.

---------------------------------------------------------
Title: Iron and Nickel spectral opacity calculations in conditions
relevant for pulsating stellar envelopes and experiments
Authors: Gilles, D.; Turck-Chièze, S.; Busquet, M.; Thais, F.; Loisel,
G.; Piau, L.; Ducret, J. E.; Blenski, T.; Blancard, C.; Cossé, P.;
Faussurier, G.; Gilleron, F.; Pain, J. C.; Porcherot, Q.; Guzik,
J. A.; Kilcrease, D. P.; Magee, N. H.; Harris, J.; Bastiani-Ceccotti,
S.; Delahaye, F.; Zeippen, C. J.
2013EPJWC..5914003G Altcode: 2012arXiv1201.4692G
Seismology of stars is strongly developing. To address this question we
have formed an international collaboration, OPAC, to perform specific
experimental measurements, compare opacity calculations, and improve the
opacity calculations in stellar codes [1]. We consider the following
opacity codes: SCO, CASSANDRA, STA, OPAS, LEDCOP, OP, SCO-RCG. Their
comparison has shown large differences for Fe and Ni in equivalent
conditions of envelopes of type II supernova precursors, temperatures
between 15 and 40 eV and densities of a few mg/cm3
[2-4]. LEDCOP, OPAS, SCO-RCG structure codes and STA give similar
results and differ from OP ones for the lower temperatures and for
spectral interval values [3]. In this work we discuss the role of
Configuration Interaction (CI) and the influence of the number of used
configurations. We present and include in the opacity code comparisons
new HULLAC-v9 calculations [5, 6] that include full CI. To illustrate
the importance of this effect we compare different CI approximations
(modes) available in HULLAC-v9 [7]. These results are compared to
previous predictions and to experimental data. Differences with OP
results are discussed.

---------------------------------------------------------
Title: The stellar opacities
Authors: Turck-Chièze, S.; Gilles, D.; Gilleron, F.; Pain, J. C.
2013sf2a.conf..105T Altcode:
Opacities are fundamental ingredients of stellar
physics. Helioseismology and asteroseismology have put in evidence
anomalies that could be attributed to an insufficient knowledge of the
photon-plasma interactions. We work on a revision of this plasma physics
in the conditions where the anomalies have been found: the region of
the iron opacity peak near log T= 5.2 and the inner radiative region of
Sun and solar-like stars. The international OPAC consortium performs
new calculations, compares them and looks for the origin of their
differences. In parallel, experimental campaigns are realized, others
are in preparation to validate some conclusions on the reliability
of the new proposed calculations. New tables for astrophysics will be
performed in the framework of the ANR OPACITY and their influence on
seismic observables will be studied. We explicit here the difficulty
of the computations together with some computation resources.

---------------------------------------------------------
Title: Solar cycle and quasi-biennial variations in helioseismic
frequencies
Authors: Tripathy, Sushanta C.; Jain, Kiran; Simoniello, Rosaria;
Hill, Frank; Turck-Chièze, Sylvaine
2013IAUS..294...73T Altcode:
The prolonged period of solar minimum between cycles 23 and 24 has
invoked a great deal of interest to understand the origin of the
unusually low solar activity. Even though the origin of solar activity
is believed to lie in the shear layer at the base of the convection
zone, the analysis of helioseismic data seem to orientate us toward
the near surface. In this context, we analyze the signature of the
quasi-biennial periodicity seen in the oscillation frequencies which
may provide additional constraints on the solar dynamo models.

---------------------------------------------------------
Title: Helioseismology with PICARD
Authors: Corbard, T.; Salabert, D.; Boumier, P.; Appourchaux, T.;
Hauchecorne, A.; Journoud, P.; Nunge, A.; Gelly, B.; Hochedez, J. F.;
Irbah, A.; Meftah, M.; Renaud, C.; Turck-Chièze, S.
2013JPhCS.440a2025C Altcode: 2013arXiv1301.6940C
PICARD is a CNES micro-satellite launched in June 2010 [17]. Its main
goal is to measure the solar shape, total and spectral irradiance during
the ascending phase of the activity cycle. The SODISM telescope onboard
PICARD also allows us to conduct a program for helioseismology in
intensity at 535.7 nm [5]. One-minute cadence low-resolution full images
are available for a so-called medium-l program, and high-resolution
images of the limb recorded every 2 minutes are used to study mode
amplification near the limb in the perspective of g-mode search. First
analyses and results from these two programs are presented here.

---------------------------------------------------------
Title: The Sun-as-a-star observations: GOLF &amp; VIRGO on SoHO,
and BiSON network
Authors: García, R. A.; Davies, G. R.; Jiménez, A.; Ballot, J.;
Mathur, S.; Salabert, D.; Chaplin, W. J.; Elsworth, Y.; Régulo, C.;
Turck-Chièze, S.
2013JPhCS.440a2040G Altcode: 2013arXiv1301.6934G
Sun-as-a-star observations are very important for the study of the
conditions within the Sun and in particular for the deep interior where
higher degree modes do not penetrate. They are also of significance
in this era of dramatic advances in stellar asteroseismology as they
are comparable to those measured in other stars by asteroseismic
missions such as CoRoT, Kepler, and MOST. More than 17 years of
continuous measurements of SoHO and more than 30 years of BiSON
observations provide very long data sets of uninterrupted helioseismic
observations. In this work, we discuss the present status of all these
facilities that continue to provide state-of-the-art measurements and
invaluable data to improve our knowledge of the deepest layers of the
Sun and its structural changes during the activity cycle.

---------------------------------------------------------
Title: Solar Neutrino Physics Oscillations: Sensitivity to the
Electronic Density in the Sun's Core
Authors: Lopes, Ilídio; Turck-Chièze, Sylvaine
2013ApJ...765...14L Altcode: 2013arXiv1302.2791L
Solar neutrinos coming from different nuclear reactions are now detected
with high statistics. Consequently, an accurate spectroscopic analysis
of the neutrino fluxes arriving on Earth's detectors becomes available,
in the context of neutrino oscillations. In this work, we explore the
possibility of using this information to infer the radial profile of the
electronic density in the solar core. So, we discuss the constraints on
the Sun's density and chemical composition that can be determined from
solar neutrino observations. This approach constitutes an independent
and alternative diagnostic to the helioseismic investigations already
done. The direct inversion method, which we propose to obtain the
radial solar electronic density profile, is almost independent of the
solar model.

---------------------------------------------------------
Title: News from the opacity consortium OPAC
Authors: Turck-Chièze, S.; Gilles, D.
2013EPJWC..4301003T Altcode:
The international OPAC consortium (see list below) was formed three
years ago. It is composed of astrophysicists, plasma physicists
and experimentalists from different laboratories. This consortium
examines specific opacity calculations used in stellar physics. They
contribute to solve the problems suggested by the astrophysical
community in performing new calculations and new experiments with laser
installation. We show here the specific example of the iron opacity peak
that plays an important role in the envelope of intermediate-mass and
massive stars and we present our first conclusions on iron and nickel.

---------------------------------------------------------
Title: The Quasi-biennial Periodicity as a Window on the Solar
Magnetic Dynamo Configuration
Authors: Simoniello, R.; Jain, K.; Tripathy, S. C.; Turck-Chièze,
S.; Baldner, C.; Finsterle, W.; Hill, F.; Roth, M.
2013ApJ...765..100S Altcode: 2012arXiv1210.6796S
Manifestations of the solar magnetic activity through periodicities
of about 11 and 2 years are now clearly seen in all solar activity
indices. In this paper, we add information about the mechanism driving
the 2-year period by studying the time and latitudinal properties of
acoustic modes that are sensitive probes of the subsurface layers. We
use almost 17 years of high-quality resolved data provided by the Global
Oscillation Network Group to investigate the solar cycle changes in
p-mode frequencies for spherical degrees l from 0 to 120 and 1600 μHz
&lt;=ν &lt;= 3500 μHz. For both periodic components of solar activity,
we locate the origin of the frequency shift in the subsurface layers
and find evidence that a sudden enhancement in amplitude occurs in just
the last few hundred kilometers. We also show that, in both cases, the
size of the shift increases toward equatorial latitudes and from minimum
to maximum solar activity, but, in agreement with previous findings,
the quasi-biennial periodicity (QBP) causes a weaker shift in mode
frequencies and a slower enhancement than that caused by the 11-year
cycle. We compare our observational findings with the features predicted
by different models, that try to explain the origin of this QBP and
conclude that the observed properties could result from the beating
between a dipole and quadrupole magnetic configuration of the dynamo.

---------------------------------------------------------
Title: Seismic diagnostics for transport of angular momentum in
stars. I. Rotational splittings from the pre-main sequence to the
red-giant branch
Authors: Marques, J. P.; Goupil, M. J.; Lebreton, Y.; Talon, S.;
Palacios, A.; Belkacem, K.; Ouazzani, R. -M.; Mosser, B.; Moya, A.;
Morel, P.; Pichon, B.; Mathis, S.; Zahn, J. -P.; Turck-Chièze, S.;
Nghiem, P. A. P.
2013A&A...549A..74M Altcode: 2012arXiv1211.1271M
Context. Rotational splittings are currently measured for several
main sequence stars and a large number of red giants with the space
mission Kepler. This will provide stringent constraints on rotation
profiles. Aims: Our aim is to obtain seismic constraints on
the internal transport and surface loss of the angular momentum of
oscillating solar-like stars. To this end, we study the evolution
of rotational splittings from the pre-main sequence to the red-giant
branch for stochastically excited oscillation modes. Methods:
We modified the evolutionary code CESAM2K to take rotationally induced
transport in radiative zones into account. Linear rotational splittings
were computed for a sequence of 1.3 M⊙ models. Rotation
profiles were derived from our evolutionary models and eigenfunctions
from linear adiabatic oscillation calculations. Results: We find
that transport by meridional circulation and shear turbulence yields
far too high a core rotation rate for red-giant models compared with
recent seismic observations. We discuss several uncertainties in the
physical description of stars that could have an impact on the rotation
profiles. For instance, we find that the Goldreich-Schubert-Fricke
instability does not extract enough angular momentum from the core
to account for the discrepancy. In contrast, an increase of the
horizontal turbulent viscosity by 2 orders of magnitude is able to
significantly decrease the central rotation rate on the red-giant
branch. Conclusions: Our results indicate that it is possible
that the prescription for the horizontal turbulent viscosity largely
underestimates its actual value or else a mechanism not included in
current stellar models of low mass stars is needed to slow down the
rotation in the radiative core of red-giant stars.

---------------------------------------------------------
Title: Seismic comparison of the 11- and 2-year cycle signatures in
the Sun
Authors: Simoniello, R.; Jain, K.; Tripathy, S. C.; Turck-Chiéze,
S.; Finsterle, W.; Roth, M.
2012AN....333.1018S Altcode: 2012arXiv1210.6182S
The solar magnetic activity consists of two periodic components: the
main cycle with a period of 11 yr and a shorter cycle with a period
of ≈2 yr. The origin of this second periodicity is still not well
understood. We use almost 15 years of long high-quality resolved data
provided by the Global Oscillation Network Group (GONG) to investigate
the solar cycle changes in p-mode oscillations with spherical degree
ℓ= 0-120 and in the range of 1600 \muHz \le\nu\le 3500 \muHz. For both
periodic components of solar magnetic activity our findings locate the
origin of the frequency shift in the subsurface layers with a sudden
enhancement in the amplitude of the shift in the last few hundred
kilometers. We also show that the size of the shift increases towards
equatorial latitudes and from minimum to maximum of solar activity. On
the other hand, the signatures of the 2-yr cycle differ from the one
of the 11-yr cycle in the magnitude of the shift, as the 2-yr cycle
causes a weaker shift in mode frequencies and a slower enhancement in
the last few hundred kilometers. Based on these findings we speculate
that a possible physical mechanism behind the quasi biennial periodicity
(QBP) could be the beating between different dynamo modes (dipole and
quadrupole mode).

---------------------------------------------------------
Title: The Long-term Dynamics of the Solar Radiative Zone: New
Results from the Solar and Heliospheric Observatory (SoHO) and Young
Solar Analogs
Authors: Turck-Chièze, S.; Couvidat, S.; Eff-Darwich, A.; Duez, V.;
García, R. A.; Mathis, S.; Mathur, S.; Piau, L.; Salabert, D.
2012ASPC..462..366T Altcode:
The Standard Solar Model (SSM) is no longer sufficient to interpret
all the observations of the radiative zone obtained with the SoHO
satellite. We recall our present knowledge of this internal region and
compare recent results with models beyond the SSM assumptions. Then
we discuss the missing processes and quantify some of them in using
observations of young solar analogs to build a more realistic view
of the Sun. This progress will be useful for understanding solar-like
stars observed by CoRoT and Kepler.

---------------------------------------------------------
Title: Solar Global Oscillations of Low-Degree modes (GOLD): The
Status of the Multi-channel Resonance Spectrometer GOLF-NG
Authors: Turck-Chièze, S.; Carton, P. -H.; Barrière, J. -C.; Pallé,
P. L.; Robillot, J. -M.; Ballot, J.; Chenus, A. -C.; Daniel-Thomas,
P.; Delbart, A.; García, R. A.; Granelli, R.; Lahonde-Hamdoun, C.;
Loiseau, D.; Mathur, S.; Piret, Y.; Salabert, D.; Simoniello, R.;
Davies, G. R.
2012ASPC..462..240T Altcode:
Low-degree pulsation modes are the best way to scrutinize stellar
cores. They also provide, due to their intrinsic nature, a way to
follow varying activity in important subsurface layers. Following
difficulties encountered with the Solar and Heliospheric Observatory
(SoHO) in 1998, we study a new design that improves the detection at
low and high frequencies in comparison with the Global Oscillations at
Low Frequency (GOLF) instrument. It is based on a substantial increase
in the counting rates to get better photon statistics, and a reduction
of the solar turbulent noise in measuring simultaneously the Doppler
velocity at 6-7 heights in the strong sodium spectral line. A prototype,
GOLF-NG (GOLF New Generation), has been built with numerous laboratory
checks of the performance and in situ solar measurements at Tenerife
in 2008 and 2010. All the required specifications are now achieved,
and so GOLD can be prepared for space observations with balloons or
satellites. The substantial improvements allow an improved detection
of weak signals at different frequencies and information on activity
indicators, as the Na D lines are sensitive to the magnetic field
between photosphere and chromosphere.

---------------------------------------------------------
Title: Radiative Properties of Stellar Plasma
Authors: Turck-Chièze, S.; Loisel, G.; Gilles, D.; Ducret, J. E.;
Piau, L.; Blenski, T.; Poirier, M.; Thais, F.; Bastiani, S.; Blancard,
C.; Busquet, M.; Caillaud, T.; Cossé, P.; Delahaye, F.; Faussurier,
G.; Gilleron, F.; Guzik, J. A.; Harris, J. W.; Kilcrease, D. P.;
Magee, N. H.; Pain, J. C.; Porcherot, Q.; Reverdin, C.; Silvert, V.;
Villette, B.; Zeippen, C.
2012ASPC..462...95T Altcode:
Opacity cross-section is an important ingredient of the secular
evolution of stars. But calculation of the opacity coefficients
is complex because of the partially ionized medium (Z ≤ 28) ion
contributions to a mixture dominated by H/He. This implies that a very
large number of lines must be considered to describe M or L transitions
and produce the mean Rosseland values. Up to now the astrophysical
community has greatly benefited from the work of the Los Alamos and
Livermore teams and also from the academic Opacity Project tables
producing also the corresponding energy spectra. Despite some opacity
measurements performed at the beginning of the nineties and related
progress, differences in the radiative forces and Rosseland mean values
are still noticed with a real impact on asteroseismic interpretations
or on diffusion in stellar models. So a new effort has been engaged
these last three years to interpret the large number of data presently
available with Solar and Heliospheric Observatory (SoHO), CoRoT and
Kepler. High energy laser and Z-pinch facilities produce plasma in
conditions of temperature and density useful for stellar conditions,
and a new series of measurements have been performed recently. In
parallel several new calculations have been done using OPAS, SCORCG,
HULLAC codes to compare with new measurements and other codes on medium
elements. The present consortium carefully checks the origin of the
discrepancies between codes. We present and mention here some results
and suggest a strategy for the years to come.

---------------------------------------------------------
Title: Solar-stellar astrophysics and dark matter
Authors: Turck-Chièze, Sylvaine; Lopes, Ilídio
2012RAA....12.1107T Altcode:
In this review, we recall how stars contribute to the search for dark
matter and the specific role of the Sun. We describe a more complete
picture of the solar interior that emerges from neutrino detections,
gravity and acoustic mode measurements of the Solar and Heliospheric
Observatory (SOHO) satellite, becoming a reference for the most common
stars in the Universe. The Sun is a unique star in that we can observe
directly the effect of dark matter. The absence of a signature related
to Weakly Interacting Massive Particles (WIMPs) in its core disfavors a
WIMP mass range below 12GeV. We give arguments to continue this search
on the Sun and other promising cases. We also examine another dark
matter candidate, the sterile neutrino, and infer the limitations of
the classical structural equations. Open questions on the young Sun,
when planets formed, and on its present internal dynamics are finally
discussed. Future directions are proposed for the next decade: a better
description of the solar core, a generalization to stars coming from
seismic missions and a better understanding of the dynamics of our
galaxy which are all crucial keys for understanding dark matter.

---------------------------------------------------------
Title: The quasi-biennial periodicity (QBP) in velocity and intensity
helioseismic observations. The seismic QBP over solar cycle 23
Authors: Simoniello, R.; Finsterle, W.; Salabert, D.; García, R. A.;
Turck-Chièze, S.; Jiménez, A.; Roth, M.
2012A&A...539A.135S Altcode: 2012arXiv1201.2773S
 Aims: We looked for signatures of quasi-biennial periodicity
(QBP) over different phases of solar cycle by means of acoustic modes
of oscillation. Low-degree p-mode frequencies are shown to be sensitive
to changes in magnetic activity due to the global dynamo. Recently
there has been reported evidence of two-year variations in p-mode
frequencies. Methods: Long high-quality helioseismic data
are provided by BiSON (Birmingham Solar Oscillation Network), GONG
(Global Oscillation Network Group), GOLF (Global Oscillation at Low
Frequency) and VIRGO (Variability of Solar IRradiance and Gravity
Oscillation) instruments. We determined the solar cycle changes in
p-mode frequencies for spherical degree ℓ = 0, 1, 2 with their
azimuthal components in the frequency range 2.5 mHz ≤ ν ≤ 3.5
mHz. Results: We found signatures of QBP at all levels of solar
activity in the modes more sensitive to higher latitudes. The signal
strength increases with latitude and the equatorial component also
seems to be modulated by the 11-year envelope. Conclusions:
The persistent nature of the seismic QBP is not observed in the
surface activity indices, where mid-term variations are found only
from time to time and mainly in periods of high activity. This feature,
together with the latitudinal dependence, provides more evidence of a
mechanism that is almost independent and different from the one that
brings the active regions up to the surface. Therefore, these findings
can be used to provide more constraints on dynamo models that consider
a further cyclic component on top of the 11-year cycle.

---------------------------------------------------------
Title: Interaction of configuration in spectral opacity calculations
for stellar physics
Authors: Gilles, D.; Turck-Chièze, S.; Busquet, M.; Thais, F.; Loisel,
G.; Piau, L.; Ducret, J. E.; Blenski, T.; Poirier, M.; Blancard, C.;
Cossé, P.; Faussurier, G.; Gilleron, F.; Pain, J. C.; Guzik, J. A.;
Kilcrease, D. P.; Magee, N. H.; Harris, J.; Bastiani-Ceccotti, S.;
Delahaye, F.; Zeippen, C. J.
2012EAS....58...51G Altcode:
We discuss the role of Configuration Interaction (CI) and the influence
of the number of configurations taken into account in the calculations
of nickel and iron spectral opacities provided by the OPAC international
collaboration, including statistical approaches (SCO, CASSANDRA, STA),
detailed accounting (OPAS, LEDCOP, OP, HULLAC-v9) or hybrid method
(SCO-RCG). Opacity calculations are presented for a temperature T of
27.3 eV and a density of 3.4 mg/cm3, conditions relevant
for pulsating stellar envelopes.

---------------------------------------------------------
Title: First Study of Dark Matter Properties with Detected Solar
Gravity Modes and Neutrinos
Authors: Turck-Chièze, S.; García, R. A.; Lopes, I.; Ballot, J.;
Couvidat, S.; Mathur, S.; Salabert, D.; Silk, J.
2012ApJ...746L..12T Altcode:
We derive new limits on the cold dark matter properties for weakly
interacting massive particles (WIMPs), potentially trapped in the
solar core by using for the first time the central temperature
constrained by boron neutrinos and the central density constrained
by the dipolar gravity modes detected with the Global Oscillations
at Low Frequency/Solar Helioseismic Observatory instrument. These
detections disfavor the presence of non-annihilating WIMPs for masses
&lt;=10 GeV and spin dependent cross-sections &gt;5 × 10-36
cm2 in the solar core but cannot constrain WIMP annihilation
models. We suggest that in the coming years helio- and asteroseismology
will provide complementary probes of dark matter.

---------------------------------------------------------
Title: Seismology of Sun and stars and related opacity laboratory
measurements
Authors: Turck-Chièze, S.
2012EAS....58...43T Altcode:
CNES, ESA and NASA have invested in helioseismic and asteroseismic
disciplines for 2 decades with SoHO (1995-2015), COROT (2006-2013),
KEPLER (2009-2014), PICARD (2010-2013) and SDO (2010-2015). These
missions focus on the stellar internal dynamics and their influence
of neighboring planets. Progress along this path requires that the
microscopic physics is well under control, but several seismic probes
indicate some discrepancies which justify new investigations of the
energy transport in radiative zones of the Sun and massive stars,
despite strong efforts dedicated to reaction rates, screening,
equation of state and opacity coefficients between 1990 and 2000. We
describe here how the OPAC consortium tackles the complex problem of
photon absorption by matter both theoretically and experimentally, by
using high energy laser facilities. These studies might be also useful
for other disciplines like fusion for energy and X-ray spectroscopy
astronomy.

---------------------------------------------------------
Title: What we know and do not know about neutrino production in stars
Authors: Turck-Chièze, Sylvaine
2011NuPhS.221..292T Altcode:
This review summarizes the necessary ingredients for determining
the neutrino production rates in stars. Then the case of the Sun is
studying. A detailed comparison between solar neutrino predictions
and each neutrino detection shows the interest of the seismic model
versus standard model. After the determination of θ12,
Δ and the inclusion of electronic neutrino transformation,
the global agreement is a noticeable success with nevertheless some
identified questions. The second part of the review is dedicated to
the important lacks in solar and stellar modelling and to the way
we are presently attacking the different problems. Such situation
encourages to pursue the effort on stellar neutrino detections and
neutrino predictions, astrophysics modelling with evident consequences
for stellar evolution, supernovae explosion and neutrino properties.

---------------------------------------------------------
Title: Comparison of Fe and Ni opacity calculations for a better
understanding of pulsating stellar envelopes
Authors: Gilles, D.; Turck-Chièze, S.; Loisel, G.; Piau, L.; Ducret,
J. -E.; Poirier, M.; Blenski, T.; Thais, F.; Blancard, C.; Cossé,
P.; Faussurier, G.; Gilleron, F.; Pain, J. C.; Porcherot, Q.; Guzik,
J. A.; Kilcrease, D. P.; Magee, N. H.; Harris, J.; Busquet, M.;
Delahaye, F.; Zeippen, C. J.; Bastiani-Ceccotti, S.
2011HEDP....7..312G Altcode: 2011HEDP....7..312.; 2012arXiv1201.6245G
Opacity is an important ingredient of the evolution of stars. The
calculation of opacity coefficients is complicated by the fact that
the plasma contains partially ionized heavy ions that contribute to
opacity dominated by H and He. Up to now, the astrophysical community
has greatly benefited from the work of the contributions of Los Alamos
[1], Livermore [2] and the Opacity Project (OP) [3]. However unexplained
differences of up to 50% in the radiative forces and Rosseland mean
values for Fe have been noticed for conditions corresponding to stellar
envelopes. Such uncertainty has a real impact on the understanding
of pulsating stellar envelopes, on the excitation of modes, and on
the identification of the mode frequencies. Temperature and density
conditions equivalent to those found in stars can now be produced
in laboratory experiments for various atomic species. Recently the
photo-absorption spectra of nickel and iron plasmas have been measured
during the LULI 2010 campaign, for temperatures between 15 and 40 eV and
densities of ∼3 mg/cm3. A large theoretical collaboration,
the "OPAC", has been formed to prepare these experiments. We present
here the set of opacity calculations performed by eight different
groups for conditions relevant to the LULI 2010 experiment and to
astrophysical stellar envelope conditions.

---------------------------------------------------------
Title: Simulations of the solar atmosphere and solar limbs
Authors: Piau, L.; Stein, R. F.; Melo, S.; Turck-Chièze, S.;
Thuillier, G.; Hauchecorne, A.
2011sf2a.conf..407P Altcode:
We perform simulations of the solar atmosphere either using the
1D hydrostatic code Atlas12 or the 3D (magneto)hydrodynamic code
Stagger. The former numerical tool relies on a phenomenology of
convection whereas the later one addresses the surface convection
directly and accounts for its dynamical effects. Once the average
atmosphere stratification is obtained it is used to perform radiative
transfer at speficic wavelengths in order to compute the solar limb
darkening. We report a ≈ 60 mas shift between inflection point
positions of limb profiles computed from 1D and 3D models. This is due
to turbulent support present in 3D simulations but not 1D. We further
report a slight decrease of the turbulent support when a moderate
magnetic field is included in the simulation which suggests that the
solar radius should be anti-correlated with the solar activity cycle.

---------------------------------------------------------
Title: Main lessons from GOLF/SOHO instrument on dynamics of the
radiative zone, fundamental physics and energetics
Authors: Turck-Chièze, S.; García, R. A.; Piau, L.; Couvidat, S.
2011sf2a.conf..257T Altcode:
The GOLF instrument aboard SoHO has reached its main objectives and
reveals its power to constrain fundamental physics, energetics and
dynamics of the radiative zone. The Standard Solar Model (SSM) is no
more sufficient to interpret all the seismic observations of the solar
radiative zone. We confront the main results of GOLF to models beyond
the SSM assumptions. We discuss the missing processes and quantify some
of them to build a more realistic view of our star. Present works on
GOLF instrument are now turned on its capability to follow the solar
activity and on a tentative to detect more gravity modes. All the
results are useful for solar-like stars observed by COROT and KEPLER.

---------------------------------------------------------
Title: Radiative properties of stellar plasmas and open challenges
Authors: Turck-Chièze, S.; Loisel, G.; Gilles, D.; Piau, L.; Blancard,
C.; Blenski, T.; Busquet, M.; Caillaud, T.; Cossé, P.; Delahaye, F.;
Faussurier, G.; Fariaut, J.; Gilleron, F.; Guzik, J. A.; Harris, J.;
Kilcrease, D. P.; Magee, N. H.; Pain, J. C.; Porcherot, Q.; Poirier,
M.; Soullier, G.; Zeippen, C. J.; Bastiani-Ceccotti, S.; Reverdin,
C.; Silvert, V.; Thais, F.; Villette, B.
2011Ap&SS.336..103T Altcode: 2011Ap&SS.tmp..367T; 2011Ap&SS.tmp..247T; 2011arXiv1101.1170T
The lifetime of solar-like stars, the envelope structure of more massive
stars, and stellar acoustic frequencies largely depend on the radiative
properties of the stellar plasma. Up to now, these complex quantities
have been estimated only theoretically. The development of the powerful
tools of helio- and astero- seismology has made it possible to gain
insights on the interiors of stars. Consequently, increased emphasis is
now placed on knowledge of the monochromatic opacity coefficients. Here
we review how these radiative properties play a role, and where they
are most important. We then concentrate specifically on the envelopes of
β Cephei variable stars. We discuss the dispersion of eight different
theoretical estimates of the monochromatic opacity spectrum and the
challenges we need to face to check these calculations experimentally.

---------------------------------------------------------
Title: From Sun to Stars: Macroscopic and Microscopic processes for
solar-like stars
Authors: Turck-Chièze, Sylvaine
2011iasa.confE..15T Altcode:
No abstract at ADS

---------------------------------------------------------
Title: The long term dynamics of the solar radiative zone associated
to new results from SoHO and young solar analogs
Authors: Turck-Chieze, Sylvaine; Couvidat, Sebastien; Eff-Darwich,
Antonio; Duez, Vincent; Garcia, Rafael A.; Mathis, Stephane; Mathur,
Savita; Piau, Laurent; Salabert, David
2011arXiv1109.4125T Altcode:
The Standard Solar Model (SSM) is no more sufficient to interpret
all the observations of the radiative zone obtained with the SoHO
satellite. We recall our present knowledge of this internal region and
compare the recent results to models beyond the SSM assumptions. Then
we discuss the missing processes and quantify some of them in using
young analog observations to build a more realistic view of our
star. This progress will be useful for solar-like stars observed by
COROT and KEPLER.

---------------------------------------------------------
Title: Solar neutrinos, helioseismology and the solar internal
dynamics
Authors: Turck-Chièze, Sylvaine; Couvidat, Sébastien
2011RPPh...74h6901T Altcode: 2010arXiv1009.0852T
Neutrinos are fundamental particles ubiquitous in the Universe and
whose properties remain elusive despite more than 50 years of intense
research activity. This review illustrates the importance of solar
neutrinos in astrophysics, nuclear physics and particle physics. After
a description of the historical context, we remind the reader of the
noticeable properties of these particles and of the stakes of the solar
neutrino puzzle. The standard solar model triggered persistent efforts
in fundamental physics to predict the solar neutrino fluxes, and its
constantly evolving predictions have been regularly compared with the
detected neutrino signals. Anticipating that this standard model could
not reproduce the internal solar dynamics, a seismic solar model was
developed which enriched theoretical neutrino flux predictions with
in situ observation of acoustic and gravity waves propagating in the
Sun. This seismic model contributed to the stabilization of the neutrino
flux predictions. This review recalls the main historical steps, from
the pioneering Homestake mine experiment and the GALLEX-SAGE experiments
capturing the first proton-proton neutrinos. It emphasizes the
importance of the SuperKamiokande and SNO detectors. Both experiments
demonstrated that the solar-emitted electron neutrinos are partially
transformed into other neutrino flavors before reaching the Earth. This
sustained experimental effort opens the door to neutrino astronomy, with
long-base lines and underground detectors. The success of BOREXINO in
detecting the 7Be neutrino signal alone instills confidence
in physicists' ability to detect each neutrino source separately. It
justifies the building of a new generation of detectors to measure the
entire solar neutrino spectrum in greater detail, as well as supernova
neutrinos. A coherent picture has emerged from neutrino physics and
helioseismology. Today, new paradigms take shape in these two fields:
neutrinos are massive particles, but their masses are still unknown,
and the research on the solar interior focuses on the dynamical
aspects and on the signature of dark matter. The magnetic moment of
the neutrino begins to be an actor in stellar evolution. The third part
of the review is dedicated to this prospect. The understanding of the
crucial role of both rotation and magnetism in solar physics benefits
from SoHO, SDO and PICARD space observations, and from a new prototype,
GOLF-NG. The magnetohydrodynamical view of the solar interior is a new
way of understanding the impact of the Sun on the Earth's environment
and climate. For now, the particle and stellar challenges seem
decoupled, but this is only a superficial appearance. The development
of asteroseismology—with the COROT and KEPLER spacecraft—and
of neutrino physics will both contribute to improvements in our
understanding of, for instance, supernova explosions. This shows the
far-reaching impact of neutrino and stellar astronomy.

---------------------------------------------------------
Title: The Solar Energetic Balance Revisited by Young Solar Analogs,
Helioseismology, and Neutrinos
Authors: Turck-Chièze, Sylvaine; Piau, Laurent; Couvidat, Sébastien
2011ApJ...731L..29T Altcode: 2011arXiv1103.2620T
The energetic balance of the standard solar model (SSM) results from
equilibrium between nuclear energy production, energy transfer, and
photospheric emission. In this Letter, we give an order of magnitude
of several percent for the loss of energy in kinetic energy, magnetic
energy, and X-ray or UV radiation during the entire solar lifetime
from the observations of the present Sun. We also estimate the loss of
mass from the observations of young solar analogs, which could reach
up to 30%. We deduce new models of the present Sun, their associated
neutrino fluxes, and internal sound-speed profile. This approach
sheds quantitative lights on the disagreement between the sound speed
obtained by helioseismology and the sound speed derived from the SSM
including the updated photospheric CNO abundances, based on recent
observations. We conclude that about 20% of the present discrepancy
could come from the incorrect description of the early phases of the
Sun, its activity, its initial mass, and mass-loss history. This study
has obvious consequences on the solar system formation and the early
evolution of the closest planets.

---------------------------------------------------------
Title: How the solar dynamics can influence the Sun-Earth medium
term relationship
Authors: Turck-Chièze, Sylvaine; Lefebvre, Sandrine
2011JASTP..73..251T Altcode:
We recall how the Sun is introduced in the present climatic models and
discuss why the solar standard model (SSM) framework is insufficient
to describe the Sun-Earth medium term relationship. We then report
on the different sources of variability. The SoHO mission allows a
comparison between two successive solar minima and puts new constraints
on the internal rotation profile. The coming space missions SDO and
PICARD will add crucial information on internal circulations and on
the superficial asphericity. The interplay between the solar dynamics
and terrestrial atmospheric models is in its infancy, it calls for
medium term uninterrupted solar observations which will take benefit
of a formation flying concept.

---------------------------------------------------------
Title: New insights on the solar core
Authors: García, R. A.; Salabert, D.; Ballot, J.; Eff-Darwich, A.;
Garrido, R.; Jiménez, A.; Mathis, S.; Mathur, S.; Moya, A.; Pallé,
P. L.; Régulo, C.; Sato, K.; Suárez, J. C.; Turck-Chièze, S.
2011JPhCS.271a2046G Altcode: 2010arXiv1012.0506G
Since the detection of the asymptotic properties of the dipole gravity
modes in the Sun, the quest to find individual gravity modes has
continued. An extensive and deeper analysis of 14 years of continuous
GOLF/SoHO observational data, unveils the presence of a pattern of peaks
that could be interpreted as individual dipole gravity modes in the
frequency range between 60 and 140 microHz, with amplitudes compatible
with the latest theoretical predictions. By collapsing the power
spectrum we have obtained a quite constant splitting for these patterns
in comparison to regions where no g modes were expected. Moreover, the
same technique applied to simultaneous VIRGO/SoHO data unveils some
common signals between the power spectra of both instruments. Thus,
we are able to identify and characterize individual g modes with their
central frequencies, amplitudes and splittings allowing to do seismic
inversions of the rotation profile inside the solar core. These results
open a new ligh t on the physics and dynamics of the solar deep core.

---------------------------------------------------------
Title: The dynamics of the radiative zone of the Sun
Authors: Turck-Chièze, S.; Couvidat, S.; Duez, V.; Mathis, S.;
Marques, J.; Palacios, A.; Piau, L.
2011JPhCS.271a2044T Altcode: 2011arXiv1101.1185T
Helioseismology puts strong constraints on the internal sound speed
and on the rotation profile in the radiative zone. Young stars of
solar type are more active and faster rotators than the Sun. So we
begin to build models which include different rotation histories and
compare the results with all the solar observations. The profiles of
the rotation we get have interesting consequence for the introduction
of magnetic field in the radiative zone. We discuss also the impact
of mass loss deduced from measured flux of young stars. We deduce from
these comparisons some quantitative effect of the dynamical processes
(rotation, magnetic field and mass loss) of these early stages on the
present sound speed and density. We show finally how we can improve
our present knowledge of the radiative zone with PICARD and GOLFNG.

---------------------------------------------------------
Title: Theoretical and experimental activities on opacities for a
good interpretation of seismic stellar probes
Authors: Turck-Chièze, S.; Loisel, G.; Gilles, D.; Thais, F.;
Bastiani, S.; Blancard, C.; Busquet, M.; Caillaud, T.; Cosse, P.;
Blenski, T.; Delahaye, F.; Educret, J.; Faussurier, G.; Gilleron,
F.; Guzik, J.; Harris, J. W.; Kilcrease, D. P.; Magee, N. H.; Piau,
L.; Pain, J. C.; Poirier, M.; Porcherot, Q.; Reverdin, C.; Silvert,
V.; Villette, B.; Zeippen, C.
2011JPhCS.271a2035T Altcode: 2011arXiv1101.1182T
Opacity calculations are basic ingredients of stellar modelling. They
play a crucial role in the interpretation of acoustic modes detected
by SoHO, COROT and KEPLER. In this review we present our activities
on both theoretical and experimental sides. We show new calculations
of opacity spectra and comparisons between eight groups who produce
opacity spectra calculations in the domain where experiments are
scheduled. Real differences are noticed with real astrophysical
consequences when one extends helioseismology to cluster studies of
different compositions. Two cases are considered presently: (1) the
solar radiative zone and (2) the beta Cephei envelops. We describe how
our experiments are performed and new preliminary results on nickel
obtained in the campaign 2010 at LULI 2000 at Polytechnique.

---------------------------------------------------------
Title: Towards a detection of individual g modes in the Sun
Authors: Garcia, R. A.; Ballot, J.; Eff-Darwich, A.; Garrido, R.;
Jimenez, A.; Mathis, S.; Mathur, S.; Moya, A.; Palle, P. L.; Regulo,
C.; Salabert, D.; Suarez, J. C.; Turck-Chieze, S.
2010arXiv1007.4445G Altcode:
Since the detection of the asymptotic properties of the dipole gravity
modes in the Sun, the quest to find the individual gravity modes has
continued. A deeper analysis of the GOLF/SoHO data unveils the presence
of a pattern of peaks that could be interpreted as individual dipole
gravity modes. The computed collapsed spectrum -around these candidate
modes- uncovers the presence of a quasi constant frequency splitting,
in contrast with regions where no g modes are expected in which
the collapsogram gives random results. Besides, the same technique
applied to VIRGO/SoHO unveils some common signals between both power
spectra. Thus, we can identify and characterize the modes, for example,
with their central frequency and splittings. This would open the path
towards new investigations to better constrain the solar core.

---------------------------------------------------------
Title: Towards a New Formation Flying Solar Coronagraph
Authors: Lamy, P.; Vives, S.; Curdt, W.; Dame, L.; Davila, J.; Defise,
J. M.; Fineschi, S.; Heinzel, P.; Kuzin, S.; Schmutz, W.; Tsinganos,
K.; Turck-Chieze, S.; Zhukov, A.
2010ASPC..424...15L Altcode:
We briefly describe an investigation aiming at the development of a
giant solar coronagraph instrument onboard of two satellites, separated
by about 150 m in formation flight for the detailed observation of the
solar coronal plasma. The European Space Agency (ESA) has selected this
instrument as the only payload onboard the Proba 3 satellites which
will be launched in 2013. The Greek team is developing the command
control board of the coronagraph.

---------------------------------------------------------
Title: Seismic and Dynamical Solar Models. I. The Impact of the
Solar Rotation History on Neutrinos and Seismic Indicators
Authors: Turck-Chièze, S.; Palacios, A.; Marques, J. P.; Nghiem,
P. A. P.
2010ApJ...715.1539T Altcode: 2010arXiv1004.1657T
Solar activity and helioseismology show the limitation of the standard
solar model and call for the inclusion of dynamical processes in both
convective and radiative zones. In this paper, we concentrate on the
radiative zone. We first recall the sensitivity of boron neutrinos
to the microscopic physics included in solar standard and seismic
models. We confront the neutrino predictions of the seismic model with
all the detected neutrino fluxes. Then, we compute new models of the Sun
including a detailed transport of angular momentum and chemicals due to
internal rotation that includes meridional circulation and shear-induced
turbulence. We use two stellar evolution codes: CESAM and STAREVOL to
estimate the different terms. We follow three temporal evolutions of the
internal rotation which differ by their initial conditions: very slow,
moderate, and fast rotation, with magnetic braking at the arrival on the
main sequence for the last two. We find that the meridional velocities
in the present solar radiative zone are extremely small in comparison
with those of the convective zone (smaller than 10-6 cm
s-1 instead of m s-1). All models lead to a
radial differential rotation profile in the radiative zone but with
a significantly different contrast. We compare these profiles to the
presumed solar internal rotation and show that if meridional circulation
and shear turbulence were the only mechanisms transporting angular
momentum within the Sun, a rather slow rotation in the young Sun is
favored. We confirm the small influence of the transport by rotation
on the sound speed profile but its potential impact on the chemicals
in the transition region between radiation and convective zones. These
models are physically more representative of the real Sun than the
standard or seismic solar models but a high initial rotation, as has
been considered previously, increases the disagreement with neutrinos
and the sound speed in the radiative zone. This present work pushes
us to pursue the inclusion of the other dynamical processes to better
reproduce the observed solar profile in the whole radiative zone and
to better describe the young active Sun. We also need to get a better
knowledge of solar gravity mode splittings to use their constraints.

---------------------------------------------------------
Title: A Multi-Site Campaign to Measure Solar-Like Oscillations in
Procyon. II. Mode Frequencies
Authors: Bedding, Timothy R.; Kjeldsen, Hans; Campante, Tiago L.;
Appourchaux, Thierry; Bonanno, Alfio; Chaplin, William J.; Garcia,
Rafael A.; Martić, Milena; Mosser, Benoit; Butler, R. Paul; Bruntt,
Hans; Kiss, László L.; O'Toole, Simon J.; Kambe, Eiji; Ando,
Hiroyasu; Izumiura, Hideyuki; Sato, Bun'ei; Hartmann, Michael;
Hatzes, Artie; Barban, Caroline; Berthomieu, Gabrielle; Michel,
Eric; Provost, Janine; Turck-Chièze, Sylvaine; Lebrun, Jean-Claude;
Schmitt, Jerome; Bertaux, Jean-Loup; Benatti, Serena; Claudi, Riccardo
U.; Cosentino, Rosario; Leccia, Silvio; Frandsen, Søren; Brogaard,
Karsten; Glowienka, Lars; Grundahl, Frank; Stempels, Eric; Arentoft,
Torben; Bazot, Michaël; Christensen-Dalsgaard, Jørgen; Dall, Thomas
H.; Karoff, Christoffer; Lundgreen-Nielsen, Jens; Carrier, Fabien;
Eggenberger, Patrick; Sosnowska, Danuta; Wittenmyer, Robert A.; Endl,
Michael; Metcalfe, Travis S.; Hekker, Saskia; Reffert, Sabine
2010ApJ...713..935B Altcode: 2010arXiv1003.0052B
We have analyzed data from a multi-site campaign to observe oscillations
in the F5 star Procyon. The data consist of high-precision velocities
that we obtained over more than three weeks with 11 telescopes. A
new method for adjusting the data weights allows us to suppress the
sidelobes in the power spectrum. Stacking the power spectrum in a
so-called échelle diagram reveals two clear ridges, which we identify
with even and odd values of the angular degree (l = 0 and 2, and l =
1 and 3, respectively). We interpret a strong, narrow peak at 446 μHz
that lies close to the l = 1 ridge as a mode with mixed character. We
show that the frequencies of the ridge centroids and their separations
are useful diagnostics for asteroseismology. In particular, variations
in the large separation appear to indicate a glitch in the sound-speed
profile at an acoustic depth of ~1000 s. We list frequencies for 55
modes extracted from the data spanning 20 radial orders, a range
comparable to the best solar data, which will provide valuable
constraints for theoretical models. A preliminary comparison with
published models shows that the offset between observed and calculated
frequencies for the radial modes is very different for Procyon than
for the Sun and other cool stars. We find the mean lifetime of the
modes in Procyon to be 1.29+0.55 -0.49 days,
which is significantly shorter than the 2-4 days seen in the Sun.

---------------------------------------------------------
Title: The Asteroseismic Potential of Kepler: First Results for
Solar-Type Stars
Authors: Chaplin, W. J.; Appourchaux, T.; Elsworth, Y.; García,
R. A.; Houdek, G.; Karoff, C.; Metcalfe, T. S.; Molenda-Żakowicz,
J.; Monteiro, M. J. P. F. G.; Thompson, M. J.; Brown, T. M.;
Christensen-Dalsgaard, J.; Gilliland, R. L.; Kjeldsen, H.; Borucki,
W. J.; Koch, D.; Jenkins, J. M.; Ballot, J.; Basu, S.; Bazot, M.;
Bedding, T. R.; Benomar, O.; Bonanno, A.; Brandão, I. M.; Bruntt,
H.; Campante, T. L.; Creevey, O. L.; Di Mauro, M. P.; Doǧan,
G.; Dreizler, S.; Eggenberger, P.; Esch, L.; Fletcher, S. T.;
Frandsen, S.; Gai, N.; Gaulme, P.; Handberg, R.; Hekker, S.; Howe,
R.; Huber, D.; Korzennik, S. G.; Lebrun, J. C.; Leccia, S.; Martic,
M.; Mathur, S.; Mosser, B.; New, R.; Quirion, P. -O.; Régulo, C.;
Roxburgh, I. W.; Salabert, D.; Schou, J.; Sousa, S. G.; Stello, D.;
Verner, G. A.; Arentoft, T.; Barban, C.; Belkacem, K.; Benatti, S.;
Biazzo, K.; Boumier, P.; Bradley, P. A.; Broomhall, A. -M.; Buzasi,
D. L.; Claudi, R. U.; Cunha, M. S.; D'Antona, F.; Deheuvels, S.;
Derekas, A.; García Hernández, A.; Giampapa, M. S.; Goupil, M. J.;
Gruberbauer, M.; Guzik, J. A.; Hale, S. J.; Ireland, M. J.; Kiss,
L. L.; Kitiashvili, I. N.; Kolenberg, K.; Korhonen, H.; Kosovichev,
A. G.; Kupka, F.; Lebreton, Y.; Leroy, B.; Ludwig, H. -G.; Mathis, S.;
Michel, E.; Miglio, A.; Montalbán, J.; Moya, A.; Noels, A.; Noyes,
R. W.; Pallé, P. L.; Piau, L.; Preston, H. L.; Roca Cortés, T.;
Roth, M.; Sato, K. H.; Schmitt, J.; Serenelli, A. M.; Silva Aguirre,
V.; Stevens, I. R.; Suárez, J. C.; Suran, M. D.; Trampedach, R.;
Turck-Chièze, S.; Uytterhoeven, K.; Ventura, R.; Wilson, P. A.
2010ApJ...713L.169C Altcode: 2010arXiv1001.0506C
We present preliminary asteroseismic results from Kepler on three G-type
stars. The observations, made at one-minute cadence during the first
33.5 days of science operations, reveal high signal-to-noise solar-like
oscillation spectra in all three stars: about 20 modes of oscillation
may be clearly distinguished in each star. We discuss the appearance of
the oscillation spectra, use the frequencies and frequency separations
to provide first results on the radii, masses, and ages of the stars,
and comment in the light of these results on prospects for inference
on other solar-type stars that Kepler will observe.

---------------------------------------------------------
Title: Concluding remarks on solar and stellar activities and
related planets
Authors: Turck-Chièze, Sylvaine
2010IAUS..264..507T Altcode: 2009arXiv0911.4740T
The symposium has shown the dynamism of this rapidly evolving
discipline. I shall concentrate here on some highlights and some
complementary informations. I conclude on open questions with some
perspectives on solar &amp; stellar activity and related planets.

---------------------------------------------------------
Title: Effect of a fossil magnetic field on the structure of a
young Sun
Authors: Duez, V.; Mathis, S.; Turck-Chièze, S.
2010MNRAS.402..271D Altcode: 2009MNRAS.tmp.1928D; 2009arXiv0911.0788D
We study the impact of a fossil magnetic field on the physical
quantities which describe the structure of a young Sun of 500
Myr. We consider for the first time a non-force-free field composed
of a mixture of poloidal and toroidal magnetic fields and propose a
specific configuration to illustrate our purpose. In this paper, we
estimate the relative role of the different terms which appear in the
modified stellar structure equations. We note that the Lorentz tension
plays a non-negligible role in addition to the magnetic pressure. This
is interesting because most of the previous stellar evolution codes
ignored that term and the geometry of the field. The solar structure
perturbations are, as already known, small and consequently we have
been able to estimate each term semi-analytically. We develop a general
treatment to calculate the global modification of the structure and of
the energetic balance. We also estimate the gravitational multipolar
moments associated with the presence of a fossil large-scale magnetic
field in radiative zone. The values given for the young Sun help the
future implementation in stellar evolution codes. This work can be
repeated for any other field configuration and prepares the achievement
of a solar magnetohydrodynamic model where we will follow the transport
of such field on secular time-scales and the associated transport of
momentum and chemicals. The described method will be applied at the
present Sun and the results will be compared with the coming balloon
or space measurements.

---------------------------------------------------------
Title: The quest for the solar g modes
Authors: Appourchaux, T.; Belkacem, K.; Broomhall, A. -M.; Chaplin,
W. J.; Gough, D. O.; Houdek, G.; Provost, J.; Baudin, F.; Boumier,
P.; Elsworth, Y.; García, R. A.; Andersen, B. N.; Finsterle, W.;
Fröhlich, C.; Gabriel, A.; Grec, G.; Jiménez, A.; Kosovichev, A.;
Sekii, T.; Toutain, T.; Turck-Chièze, S.
2010A&ARv..18..197A Altcode: 2010A&ARv.tmp....1A; 2009arXiv0910.0848A
Solar gravity modes (or g modes)—oscillations of the solar interior
on which buoyancy acts as the restoring force—have the potential
to provide unprecedented inference on the structure and dynamics of
the solar core, inference that is not possible with the well-observed
acoustic modes (or p modes). The relative high amplitude of the g-mode
eigenfunctions in the core and the evanesence of the modes in the
convection zone make the modes particularly sensitive to the physical
and dynamical conditions in the core. Owing to the existence of the
convection zone, the g modes have very low amplitudes at photospheric
levels, which makes the modes extremely hard to detect. In this article,
we review the current state of play regarding attempts to detect g
modes. We review the theory of g modes, including theoretical estimation
of the g-mode frequencies, amplitudes and damping rates. Then we go
on to discuss the techniques that have been used to try to detect g
modes. We review results in the literature, and finish by looking to
the future, and the potential advances that can be made—from both
data and data-analysis perspectives—to give unambiguous detections
of individual g modes. The review ends by concluding that, at the time
of writing, there is indeed a consensus amongst the authors that there
is currently no undisputed detection of solar g modes.

---------------------------------------------------------
Title: Interior and Exterior Clues of Solar Activity
Authors: Turck-Chièze, S.; Brun, A. S.; Duez, V.; García, R. A.;
Mathis, S.; Piau, L.; Salabert, D.; Pallé, P. L.; Jiménez-Reyes,
S. J.; Mathur, S.; Simoniello, R.; Robillot, J. M.
2010ASSP...19..368T Altcode: 2010mcia.conf..368T
Two research paths are described to obtain better understanding
of the origin of global solar activity. First, observations with
a multichannel resonant spectrometer may reveal the dynamics of the
solar core, the tachocline, and the temporal evolution of activity
between the photosphere and chromosphere. Such new observations will
deliver constraints for 3D simulations of solar activity. Second, we
examine the ab-initio introduction of a non-force-free field expressed
in spherical harmonics into the solar structure equations and estimate
its impact on the inner and subsurface layers, its time evolution,
and its role in angular momentum transport.

---------------------------------------------------------
Title: ASPIICS / PROBA-3: a formation flying externally-occulted
giant coronagraph mission
Authors: Lamy, Philippe; Damé, Luc; Curdt, W.; Davila, J.; Defise,
J. M.; Fineschi, S.; Heinzel, P.; Howard, R.; Kuzin, S.; Schmutz,
W.; Tsinganos, K.; Turck-Chièze, S.; Zhukov, A.
2010cosp...38.2858L Altcode: 2010cosp.meet.2858L
Classical externally-occulted coronagraphs are presently limited in
their performances by the distance between the external occulter and
the front objective. The diffraction fringe from the occulter and
the vignetted pupil which degrades the spatial resolution prevent
useful observa-tions of the white light corona inside typically 2-2.5
Rsun. Formation flying offers an elegant solution to these limitations
and allows conceiving giant, externally-occulted coronagraphs
us-ing a two-component space system with the external occulter on
one spacecraft and the optical instrument on the other spacecraft
at distances of hundred meters. Such an instrument has just been
selected by ESA to fly (by the end of 2013) on its PROBA-3 mission,
presently in phase B, to demonstrate formation flying. It will perform
both high spatial resolution imaging of the solar corona as well as
2-dimensional spectroscopy of several emission lines (in partic-ular
the forbidden line of FeXIV at 530.285 nm) from the coronal base out
to 3 Rsun using a Fabry-Perot interferometer. The classical design of
an externally-occulted coronagraph is adapted to the formation flying
configuration allowing the detection of the very inner corona as close
as 0.05 Rsun from the solar limb. By tuning the position of the occulter
spacecraft, it may even be possible to try reaching the chromosphere
and the upper part of the spicules. ASPIICS/PROBA-3 mission, payload
and scientific objectives are detailed.

---------------------------------------------------------
Title: Multi-spacecraft observation of a magnetic cloud
Authors: de Lucas, Aline; Dal Lago, Alisson; Schwenn, Rainer; Clúa de
Gonzalez, Alicia L.; Marsch, Eckart; Lamy, Philippe; Damé, Luc; Curdt,
W.; Davila, J.; Defise, J. M.; Fineschi, S.; Heinzel, P.; Howard, R.;
Kuzin, S.; Schmutz, W.; Tsinganos, K.; Turck-Chièze, S.; Zhukov, A.
2010cosp...38.1921D Altcode: 2010cosp.meet.1921D
Classical externally-occulted coronagraphs are presently limited in
their performances by the distance between the external occulter and
the front objective. The diffraction fringe from the occulter and
the vignetted pupil which degrades the spatial resolution prevent
useful observa-tions of the white light corona inside typically 2-2.5
Rsun. Formation flying offers an elegant solution to these limitations
and allows conceiving giant, externally-occulted coronagraphs
us-ing a two-component space system with the external occulter on
one spacecraft and the optical instrument on the other spacecraft
at distances of hundred meters. Such an instrument has just been
selected by ESA to fly (by the end of 2013) on its PROBA-3 mission,
presently in phase B, to demonstrate formation flying. It will perform
both high spatial resolution imaging of the solar corona as well as
2-dimensional spectroscopy of several emission lines (in partic-ular
the forbidden line of FeXIV at 530.285 nm) from the coronal base out
to 3 Rsun using a Fabry-Perot interferometer. The classical design of
an externally-occulted coronagraph is adapted to the formation flying
configuration allowing the detection of the very inner corona as close
as 0.05 Rsun from the solar limb. By tuning the position of the occulter
spacecraft, it may even be possible to try reaching the chromosphere
and the upper part of the spicules. ASPIICS/PROBA-3 mission, payload
and scientific objectives are presented.

---------------------------------------------------------
Title: First Performance of the GOLF-NG Instrumental Prototype
Observing the Sun in Tenerife
Authors: Salabert, D.; Turck-Chièze, S.; Barrière, J. C.; Carton,
P. H.; Daniel-Thomas, P.; Delbart, A.; García, R. A.; Granelli, R.;
Jiménez-Reyes, S. J.; Lahonde-Hamdoun, C.; Loiseau, D.; Mathur, S.;
Nunio, F.; Pallé, P. L.; Piret, Y.; Robillot, J. M.; Simoniello, R.
2009ASPC..416..341S Altcode: 2008arXiv0810.3393S
The primary challenge of Global Oscillations at Low Frequency New
Generation (GOLF-NG) is the detection of the low-frequency solar
gravity and acoustic modes, as well as the possibility to measure
the high-frequency chromospheric modes. On June 8th 2008, the
first sunlight observations with the multichannel resonant GOLF-NG
prototype spectrometer were obtained at the Observatorio del Teide
(Tenerife). The instrument performs integrated (Sun-as-a-star),
Doppler velocity measurements, simultaneously at eight different
heights in the D1 sodium line profile, corresponding to photospheric
and chromospheric layers of the solar atmosphere. In order to study
its performance, to validate the conceived strategy, and to estimate
the necessary improvements, this prototype has been running on a
daily basis over the whole summer of 2008 at the Observatorio del
Teide. We present here the results of the first GOLF-NG observations,
clearly showing the characteristics of the 5-minute oscillatory signal
at different heights in the solar atmosphere. We compare these signals
with simultaneous observations from Global Oscillations at Low Frequency
(GOLF)/SoHO and from the Mark-I instrument—a node of the Birmingham
Solar Oscillations Network (BiSON) network, operating at the same site.

---------------------------------------------------------
Title: What Can We Learn on the Structure and the Dynamics of the
Solar Core with g Modes?
Authors: Mathur, S.; Ballot, J.; Eff-Darwich, A.; García, R. A.;
Jiménez-Reyes, S. J.; Korzennik, S. G.; Turck-Chièze, S.
2009ASPC..416..215M Altcode: 2008arXiv0810.2031M
The detection of the signature of dipole gravity modes has opened the
path to study the solar inner radiative zone. Indeed, g modes should
be the best probes to infer the properties of the solar nuclear core
that represents more than half of the total mass of the Sun. Concerning
the dynamics of the solar core, we can study how future observations
of individual g modes could enhance our knowledge of the rotation
profile of the deep radiative zone. Applying inversions on a set of
real p-mode splittings coupled with either one or several g modes,
we have checked the improvement of the inferred rotation profile when
different error bars are considered for the g modes. Moreover, using a
new methodology based on the analysis of the almost constant separation
of the dipole gravity modes, we can introduce new constraints on solar
models. For that purpose, we can compare g-mode predictions computed
from several models including different physical inputs with the g-mode
asymptotic signature detected in Global Oscillations at Low Frequencies
(GOLF) data and calculate the correlation. This work shows the great
consistency between the signature of dipole gravity modes and our
knowledge of p-modes: incompatibility of data with a present standard
model including the Asplund composition.

---------------------------------------------------------
Title: Detecting individual gravity modes in the Sun
Authors: Garcia, R. A.; Ballot, J.; Eff-Darwich, A.; Garrido, R.;
Jimenez, A.; Mathis, S.; Moya, A.; Palle, P. L.; Regulo, C.; Salabert,
D.; Suarez, J. C.; Turck-Chieze, S.
2009arXiv0911.5442G Altcode:
Many questions are still open regarding the structure and the dynamics
of the solar core. By constraining more this region in the solar
evolution models, we can reduce the incertitudes on some physical
processes and on momentum transport mechanisms. A first big step was
made with the detection of the signature of the dipole-gravity modes
in the Sun, giving a hint of a faster rotation rate inside the core. A
deeper analysis of the GOLF/SoHO data unveils the presence of a pattern
of peaks that could be interpreted as dipole gravity modes. In that
case, those modes can be characterized, thus bringing better constraints
on the rotation of the core as well as some structural parameters such
as the density at these very deep layers of the Sun interior.

---------------------------------------------------------
Title: Impact of the physical processes in the modeling of HD 49933
Authors: Piau, L.; Turck-Chièze, S.; Duez, V.; Stein, R. F.
2009A&A...506..175P Altcode: 2009arXiv0907.4336P
Context: On its asteroseismic side, the initial run of CoRoT was
partly devoted to the solar like star HD 49933. The eigenmodes of this
F dwarf have been observed with unprecedented accuracy. Aims:
We investigate quantitatively the impact of changes in the modeling
parameters like mass and composition. More importantly we investigate
how a sophisticated physics affects the seismological picture of
HD 49933. We consider the effects of diffusion, rotation and the
changes in convection efficiency. Methods: We use the CESAM
stellar evolution code coupled to the ADIPLS adiabatic pulsation
package to build secular models and their associated oscillation
frequencies. We also exploited the hydrodynamical code STAGGER to
perform surface convection calculations. The seismic variables used in
this work are: the large frequency separation, the derivative of the
surface phase shift, and the eigenfrequencies νℓ=0,n=14
and νℓ=0,n=27. Results: Mass and uncertainties on
the composition have much larger impacts on the seismic variables we
consider than the rotation. The derivative of the surface phase shift is
a promising variable for the determination of the helium content. The
seismological variables of HD 49933 are sensitive to the assumed solar
composition and also to the presence of diffusion in the models.

---------------------------------------------------------
Title: On plasma radiative properties in stellar conditions
Authors: Turck-Chièze, S.; Delahaye, F.; Gilles, D.; Loisel, G.;
Piau, L.
2009HEDP....5..132T Altcode: 2012arXiv1201.4693T
The knowledge of stellar evolution is evolving quickly thanks to
an increased number of opportunities to scrutinize the stellar
internal plasma properties by stellar seismology and by 1D and
3D simulations. These new tools help us to introduce the internal
dynamical phenomena in stellar modeling. A proper inclusion of these
processes supposes a real confidence in the microscopic physics used,
partly checked by solar or stellar acoustic modes. In the present paper
we first recall which fundamental physics has been recently verified by
helioseismology. Then we recall that opacity is an important ingredient
of the secular evolution of stars and we point out why it is necessary
to measure absorption coefficients and degrees of ionization in the
laboratory for some well identified astrophysical conditions. We
examine two specific experimental conditions which are accessible
to large laser facilities and are suitable to solve some interesting
questions of the stellar community: are the solar internal radiative
interactions properly estimated and what is the proper role of the
opacity in the excitation of the non-radial modes in the envelop of
the β Cepheids and the Be stars? At the end of the paper we point out
the difficulties of the experimental approach that we need to overcome.

---------------------------------------------------------
Title: Impact of large-scale magnetic fields on stellar structure
and evolution
Authors: Duez, Vincent; Mathis, S.; Brun, A. S.; Turck-Chièze, S.
2009IAUS..259..177D Altcode:
We study the impact on the stellar structure of a large-scale magnetic
field in stellar radiation zones. The field is in magneto-hydrostatic
(MHS) equilibrium and has a non force-free character, which allows
us to study its influence both on the mechanical and and on the
energetic balances. This approach is illustrated in the case
of an Ap star where the magnetic field matches at the
surface with an external potential one. Perturbations of the stellar
structure are semi-analytically computed. The relative importance of
the magnetic physical quantities is discussed and a hierarchy, aiming
at distinguishing various refinement degrees in the implementation
of a large-scale magnetic field in a stellar evolution code, is
established. This treatment also allows us to deduce the gravitational
multipolar moments and the change in effective temperature associated
with the presence of a magnetic field.

---------------------------------------------------------
Title: DynaMICCS: The Sun as an Integrated Magnetic System
Authors: Turck-Chièze, S.; Mathis, S.
2009EM&P..104...11T Altcode: 2008EM&P..tmp...36T
After the observations of SoHO, there is a real need to pursue
global solar observations from the core to the corona and to put new
constraints on the dynamical processes which act inside and outside
the Sun. The DynaMICCS mission proposed to ESA in the framework of
COSMIC VISION 2015-2025 has this objective. We concentrate here on
the motivations to look for the magnetism of the solar radiative zone.

---------------------------------------------------------
Title: Impact of a Large-Scale Magnetic Field on Stellar Structure
Authors: Duez, V.; Mathis, S.; Brun, A. S.; Turck-Chièze, S.
2009AIPC.1121...55D Altcode:
We present the derivation of non force-free magneto-hydrostatic (MHS)
equilibria in spherical geometry, supposing any prescription for the
toroidal current. This allows us to study the influence on the stellar
structure of a large-scale magnetic field, both on the mechanical
and on the energetical balances. Two cases illustrate this approach:
(i) the field is buried below a given radius, in order to model
deep fossil magnetic fields in solar-like stars; (ii) the internal
field matches at the surface with an external potential magnetic
field that corresponds to fossil fields in more massive stars. The
stellar structure perturbations are semi-analytically computed in both
cases. This allows us to establish a hierarchy between the orders of
magnitude of the different terms. Finally, the limit of validity of
the linear perturbation is discussed.

---------------------------------------------------------
Title: The DynaMICCS perspective. A mission for a complete and
continuous view of the Sun dedicated to magnetism, space weather
and space climate
Authors: Turck-Chièze, S.; Lamy, P.; Carr, C.; Carton, P. H.;
Chevalier, A.; Dandouras, I.; Defise, J. M.; Dewitte, S.; Dudok de Wit,
T.; Halain, J. P.; Hasan, S.; Hochedez, J. F.; Horbury, T.; Levacher,
P.; Meissonier, M.; Murphy, N.; Rochus, P.; Ruzmaikin, A.; Schmutz,
W.; Thuillier, G.; Vivès, S.
2009ExA....23.1017T Altcode: 2008ExA...tmp...42T
The DynaMICCS mission is designed to probe and understand the dynamics
of crucial regions of the Sun that determine solar variability,
including the previously unexplored inner core, the radiative/convective
zone interface layers, the photosphere/chromosphere layers and the
low corona. The mission delivers data and knowledge that no other
known mission provides for understanding space weather and space
climate and for advancing stellar physics (internal dynamics)
and fundamental physics (neutrino properties, atomic physics,
gravitational moments...). The science objectives are achieved
using Doppler and magnetic measurements of the solar surface,
helioseismic and coronographic measurements, solar irradiance at
different wavelengths and in-situ measurements of plasma/energetic
particles/magnetic fields. The DynaMICCS payload uses an original
concept studied by Thalès Alenia Space in the framework of the
CNES call for formation flying missions: an external occultation of
the solar light is obtained by putting an occulter spacecraft 150 m
(or more) in front of a second spacecraft. The occulter spacecraft,
a LEO platform of the mini sat class, e.g. PROTEUS, type carries
the helioseismic and irradiance instruments and the formation flying
technologies. The latter spacecraft of the same type carries a visible
and infrared coronagraph for a unique observation of the solar corona
and instrumentation for the study of the solar wind and imagers. This
mission must guarantee long (one 11-year solar cycle) and continuous
observations (duty cycle &gt; 94%) of signals that can be very weak
(the gravity mode detection supposes the measurement of velocity
smaller than 1 mm/s). This assumes no interruption in observation
and very stable thermal conditions. The preferred orbit therefore is
the L1 orbit, which fits these requirements very well and is also an
attractive environment for the spacecraft due to its low radiation and
low perturbation (solar pressure) environment. This mission is secured
by instrumental R and D activities during the present and coming
years. Some prototypes of different instruments are already built
(GOLFNG, SDM) and the performances will be checked before launch on
the ground or in space through planned missions of CNES and PROBA ESA
missions (PICARD, LYRA, maybe ASPIICS).

---------------------------------------------------------
Title: The Dynamics perspective including the observation of the
deep solar magnetism
Authors: Turck-Chièze, S.
2009EAS....39...69T Altcode:
The stellar internal magnetism is presently poorly known, even we
have now some evidence that it plays a crucial role in different
stages of stellar evolution. I first recall the helioseismic results
coming from the SOHO mission on the deep interior. Then I show how
we hope to observe directly or indirectly the deep solar magnetism
by the simultaneous detection of gravity modes, acoustic modes and
other phenomena. The two following sections compare the different
techniques of observation and show the interest of a multichannel
resonant spectrometer both for studying the deep dynamics of the core
and for putting some constraints on the stellar atmospheric models. The
last section describes the DynaMICCS mission submitted to ESA in the
framework of Cosmic Vision 2015-2025 and the observations of the coming
decade with the GOLF-NG instrument dedicated to the magnetism of the
core and to the region located between photosphere and chromosphere.

---------------------------------------------------------
Title: Impact of a Radius and Composition Variation on Stratification
of the Solar Subsurface Layers
Authors: Lefebvre, S.; Nghiem, P. A. P.; Turck-Chièze, S.
2009ApJ...690.1272L Altcode: 2008arXiv0809.1726L
Several works have reported changes of the Sun's subsurface
stratification inferred from f-mode or p-mode observations. Recently,
a nonhomologous variation of the subsurface layers with depth and time
has been deduced from f-modes. Progress on this important transition
zone between the solar interior and the external part supposes a good
understanding of the interplay between the different processes which
contribute to this variation. This paper is the first of a series where
we aim to study these layers from the theoretical point of view. For
this first paper, we use solar models obtained with the CESAM code,
in its classical form, and analyze the properties of the computed
theoretical f-modes. We examine how a pure variation in the calibrated
radius influences the subsurface structure and we also show the impact
of an additional change of composition on the same layers. Then we use
an inversion procedure to quantify the corresponding f-mode variation
and its capacity to infer the radius variation. We deduce an estimate
of the amplitude of the 11 year cyclic photospheric radius variation.

---------------------------------------------------------
Title: The Rotation of the Solar Core
Authors: Turck-Chièze, S.
2009LNP...765..123T Altcode:
In order to get a unified representation of stars, one needs to
introduce the internal dynamical processes in the stellar structure
equations. The validation of these complex equations supposes a proper
reproduction of the helioseismic observations. Indeed the helioseismic
discipline can provide today a crucial insight into the solar internal
rotation profile, thanks to acoustic modes and to the first gravity mode
detections. This information largely improves the previous situation
where only external stellar rotation rates or abundance anomalies were
accessible. In this review, I summarize first the theoretical studies
and our recent results; then I present the respective role of acoustic
and gravity modes and I show the solar rotation profile deduced from
the instruments onboard SoHO with its uncertainties. The confrontation
of these results with the recent theoretical developments exhibits
important differences which demonstrate that some complementary work
is necessary on both observational and theoretical sides.

---------------------------------------------------------
Title: First asteroseismic results from CoRoT
Authors: Michel, E.; Baglin, A.; Weiss, W. W.; Auvergne, M.; Catala,
C.; Aerts, C.; Appourchaux, T.; Barban, C.; Baudin, F.; Briquet, M.;
Carrier, F.; Degroote, P.; De Ridder, J.; Garcia, R. A.; Garrido,
R.; Gutiérrez-Soto, J.; Kallinger, T.; Lefevre, L.; Neiner,
C.; Poretti, E.; Samadi, R.; Sarro, L.; Alecian, G.; Andrade, L.;
Ballot, J.; Benomar, O.; Berthomieu, G.; Boumier, P.; Charpinet, S.;
de Batz, B.; Deheuvels, S.; Dupret, M. -A.; Emilio, M.; Fabregat,
J.; Facanha, W.; Floquet, M.; Frémat, Y.; Fridlund, M.; Goupil,
M. -J.; Grotsch-Noels, A.; Handler, G.; Huat, A. -L.; Hubert, A. -M.;
Janot-Pacheco, E.; Kjeldsen, H.; Lebreton, Y.; Leroy, B.; Martayan,
C.; Mathias, P.; Miglio, A.; Montalban, J.; Monteiro, M. J. P. F. G.;
Mosser, B.; Provost, J; Regulo, C.; Renan de Medeiros, J.; Ribas,
I.; Roca Cortés, T.; Roxburgh, I.; Suso, J.; Thoul, A.; Toutain, T.;
Tiphene, D.; Turck-Chieze, S.; Vauclair, S.; Vauclair, G.; Zwintz, K.
2008CoAst.156...73M Altcode:
About one year after the end of the first observational run and
six months after the first CoRoT data delivery, we comment the data
exploitation progress for different types of stars. We consider first
results to illustrate how these data of unprecedented quality shed a
new light on the field of stellar seismology.

---------------------------------------------------------
Title: Impact of Large-Scale Magnetic Fields on Stellar Structure
and Prospectives on Stellar Evolution
Authors: Duez, V.; Mathis, S.; Brun, A. -S.; Turck-Chièze, S.
2008sf2a.conf..459D Altcode:
The influence of large-scale magnetic fields on stellar structure
and stellar evolution is semi-analytically considered. The magnetic
field is derived for a given axisymmetric azimuthal current, and is non
force-free, acting thus directly on the stellar structure by modifying
the hydrostatic balance. We discuss the relative importance of the
various terms associated with the magnetic field in the mechanical
and thermal balances before implementing its effects in a 1D stellar
evolution code in a way that preserves its geometrical properties. Our
purpose is illustrated by the case of an internal magnetic field
matching at the surface of an Ap star with an external potential and
multipolar magnetic field.

---------------------------------------------------------
Title: A Multisite Campaign to Measure Solar-like Oscillations in
Procyon. I. Observations, Data Reduction, and Slow Variations
Authors: Arentoft, Torben; Kjeldsen, Hans; Bedding, Timothy R.;
Bazot, Michaël; Christensen-Dalsgaard, Jørgen; Dall, Thomas H.;
Karoff, Christoffer; Carrier, Fabien; Eggenberger, Patrick; Sosnowska,
Danuta; Wittenmyer, Robert A.; Endl, Michael; Metcalfe, Travis S.;
Hekker, Saskia; Reffert, Sabine; Butler, R. Paul; Bruntt, Hans;
Kiss, László L.; O'Toole, Simon J.; Kambe, Eiji; Ando, Hiroyasu;
Izumiura, Hideyuki; Sato, Bun'ei; Hartmann, Michael; Hatzes, Artie;
Bouchy, Francois; Mosser, Benoit; Appourchaux, Thierry; Barban,
Caroline; Berthomieu, Gabrielle; Garcia, Rafael A.; Michel, Eric;
Provost, Janine; Turck-Chièze, Sylvaine; Martić, Milena; Lebrun,
Jean-Claude; Schmitt, Jerome; Bertaux, Jean-Loup; Bonanno, Alfio;
Benatti, Serena; Claudi, Riccardo U.; Cosentino, Rosario; Leccia,
Silvio; Frandsen, Søren; Brogaard, Karsten; Glowienka, Lars; Grundahl,
Frank; Stempels, Eric
2008ApJ...687.1180A Altcode: 2008arXiv0807.3794A
We have carried out a multisite campaign to measure oscillations in
the F5 star Procyon A. We obtained high-precision velocity observations
over more than three weeks with 11 telescopes, with almost continuous
coverage for the central 10 days. This represents the most extensive
campaign so far organized on any solar-type oscillator. We describe in
detail the methods we used for processing and combining the data. These
involved calculating weights for the velocity time series from the
measurement uncertainties and adjusting them in order to minimize the
noise level of the combined data. The time series of velocities for
Procyon shows the clear signature of oscillations, with a plateau of
excess power that is centered at 0.9 mHz and is broader than has been
seen for other stars. The mean amplitude of the radial modes is 38.1
+/- 1.3 cm s-1 (2.0 times solar), which is consistent with
previous detections from the ground and by the WIRE spacecraft, and
also with the upper limit set by the MOST spacecraft. The variation
of the amplitude during the observing campaign allows us to estimate
the mode lifetime to be 1.5+ 1.9-0.8 days. We
also find a slow variation in the radial velocity of Procyon, with good
agreement between different telescopes. These variations are remarkably
similar to those seen in the Sun, and we interpret them as being due to
rotational modulation from active regions on the stellar surface. The
variations appear to have a period of about 10 days, which presumably
equals the stellar rotation period or, perhaps, half of it. The amount
of power in these slow variations indicates that the fractional area of
Procyon covered by active regions is slightly higher than for the Sun.

---------------------------------------------------------
Title: Variations of the solar granulation motions with height using
the GOLF/SoHO experiment
Authors: Lefebvre, S.; García, R. A.; Jiménez-Reyes, S. J.;
Turck-Chièze, S.; Mathur, S.
2008A&A...490.1143L Altcode: 2008arXiv0808.0422L
Context: Below 1 mHz, the power spectrum of helioseismic velocity
measurements is dominated by the spectrum of convective motions
(granulation and supergranulation) and it is difficult to detect the
low-order acoustic modes and gravity modes. Aims: We attempt
to understand more clearly the behavior of solar granulation as a
function of observing height in the solar atmosphere and with magnetic
activity during solar cycle 23. Methods: We analyze the Power
Spectral Density (PSD) of eleven years of GOLF/SOHO velocity time
series data using a Harvey-type model to characterize the properties
of the convective motions in the solar oscillation power spectrum. We
study the evolution of the granulation with both altitude in the solar
atmosphere and solar activity. Results: We first demonstrate that
the traditional use of a Lorentzian profile to describe the envelope
of the p modes is unsuitable for GOLF data. To model properly the solar
spectrum, we must instead adopt a second Lorentzian profile. Secondly,
we show that the granulation clearly evolves with height in the
photosphere but does not present any significant variation with the
activity cycle.

---------------------------------------------------------
Title: Impact of Large-Scale Magnetic Fields on Solar Structure
Authors: Duez, V.; Mathis, S.; Brun, A. -S.; Turck-Chièze, S.;
Le Poncin-Lafitte, C.
2008sf2a.conf..463D Altcode:
We here focus on the impact of large-scale magnetic fields on the solar
structure from its core up to its surface by treating semi-analytically
the Magneto-HydroStatic (MHS) equilibria of a self-gravitating spherical
shell. Then, the modifications of the internal structure of the Sun
introduced by such a field are deduced, and the resulting multipolar
gravitational moments are obtained.

---------------------------------------------------------
Title: Solar structure models
Authors: Turck-Chièze, Sylvaine; Phi Nghiem, Phu Anh; Mathis,
Stéphane
2008JPhCS.118a2030T Altcode:
The Sun is a unique object in stellar evolution due to our unprecedent
insight on its internal processes. We will illustrate in this review
how the transition between a static vision to a more dynamical vision
modifies the addressing questions on the solar radiative zone. Neutrinos
and acoustic modes have first scrutinized the microscopic properties of
the solar radiative plasma. Today, stimulated by the internal rotation
profile determination, new questions emerge on the angular momentum
transport by rotation, internal waves and on the role of magnetic fields
to get access to the dynamical motions of this important region of the
Sun. We will give some examples which demonstrate that the Sun is not
yet under control.

---------------------------------------------------------
Title: Oscillations in Procyon A: First results from a multi-site
campaign
Authors: Hekker, S.; Arentoft, T.; Kjeldsen, H.; Bedding, T. R.;
Christensen-Dalsgaard, J.; Reffert, S.; Bruntt, H.; Butler, R. P.;
Kiss, L. L.; O'Toole, S. J.; Kambe, E.; Ando, H.; Izumiura, H.;
Sato, B.; Hartmann, M.; Hatzes, A. P.; Appourchaux, T.; Barban, C.;
Berthomieu, G.; Bouchy, F.; García, R. A.; Lebrun, J. -C.; Martić,
M.; Michel, E.; Mosser, B.; Nghiem, P. A. P.; Provost, J.; Samadi,
R.; Thévenin, F.; Turck-Chièze, S.; Bonanno, S. A.; Benatti, S.;
Claudi, R. U.; Cosentino, R.; Leccia, S.; Frandsen, S.; Brogaard,
K.; Grundahl, F.; Stempels, H. C.; Bazot, M.; Dall, T. H.; Karoff,
C.; Carrier, F.; Eggenberger, P.; Sosnowska, D.; Wittenmyer, R. A.;
Endl, M.; Metcalfe, T. S.
2008JPhCS.118a2059H Altcode: 2007arXiv0710.3772H
Procyon A is a bright F5IV star in a binary system. Although the
distance, mass and angular diameter of this star are all known with high
precision, the exact evolutionary state is still unclear. Evolutionary
tracks with different ages and different mass fractions of hydrogen
in the core pass, within the errors, through the observed position of
Procyon A in the Hertzsprung-Russell diagram. For more than15 years
several different groups have studied the solar-like oscillations in
Procyon A to determine its evolutionary state. Although several studies
independently detected power excess in the periodogram, there is no
agreement on the actual oscillation frequencies yet. This is probably
due to either insufficient high-quality data (i.e., aliasing) or due
to intrinsic properties of the star (i.e., short mode lifetimes). Now
a spectroscopic multi-site campaign using 10 telescopes world-wide
(minimizing aliasing effects) with a total time span of nearly 4
weeks (increase the frequency resolution) is performed to identify
frequencies in this star and finally determine its properties and
evolutionary state.

---------------------------------------------------------
Title: CoRoT Measures Solar-Like Oscillations and Granulation in
Stars Hotter Than the Sun
Authors: Michel, Eric; Baglin, Annie; Auvergne, Michel; Catala,
Claude; Samadi, Reza; Baudin, Frédéric; Appourchaux, Thierry; Barban,
Caroline; Weiss, Werner W.; Berthomieu, Gabrielle; Boumier, Patrick;
Dupret, Marc-Antoine; Garcia, Rafael A.; Fridlund, Malcolm; Garrido,
Rafael; Goupil, Marie-Jo; Kjeldsen, Hans; Lebreton, Yveline; Mosser,
Benoît; Grotsch-Noels, Arlette; Janot-Pacheco, Eduardo; Provost,
Janine; Roxburgh, Ian W.; Thoul, Anne; Toutain, Thierry; Tiphène,
Didier; Turck-Chieze, Sylvaine; Vauclair, Sylvie D.; Vauclair,
Gérard P.; Aerts, Conny; Alecian, Georges; Ballot, Jérôme;
Charpinet, Stéphane; Hubert, Anne-Marie; Lignières, François;
Mathias, Philippe; Monteiro, Mario J. P. F. G.; Neiner, Coralie;
Poretti, Ennio; Renan de Medeiros, José; Ribas, Ignasi; Rieutord,
Michel L.; Roca Cortés, Teodoro; Zwintz, Konstanze
2008Sci...322..558M Altcode: 2008arXiv0812.1267M
Oscillations of the Sun have been used to understand its interior
structure. The extension of similar studies to more distant stars
has raised many difficulties despite the strong efforts of the
international community over the past decades. The CoRoT (Convection
Rotation and Planetary Transits) satellite, launched in December 2006,
has now measured oscillations and the stellar granulation signature
in three main sequence stars that are noticeably hotter than the
sun. The oscillation amplitudes are about 1.5 times as large as
those in the Sun; the stellar granulation is up to three times as
high. The stellar amplitudes are about 25% below the theoretic values,
providing a measurement of the nonadiabaticity of the process ruling
the oscillations in the outer layers of the stars.

---------------------------------------------------------
Title: The GOLF-NG prototype and the solar European perspective for
cosmic vision 2015-2025
Authors: Turck-Chièze, Sylvaine; Mathur, Savita; Ballot, Jérome;
García, Rafael A.; Carton, Pierre-Henri; Barrière, Jean-Christophe;
Daniel-Thomas, Philippe; Delbart, Alain; Desforges, Daniel; Granelli,
Rémi; Nunio, Francois; Piret, Yves; Pallé, Pere L.; Jiménez, Antonio
J.; Jiménez-Reyes, Sébastian J.; Simoniello, Rosaria; Dyna MICCS Team
2008JPhCS.118a2044T Altcode:
The progress on the dynamics of the radiative zone by global Doppler
velocity measurements aboard SoHO (GOLF+ MDI) and with ground networks
(BiSON and GONG) opens a new perspective for solar and stellar
physics. It is why we prepare a new generation of solar resonant
spectrometer. The objectives of the GOLF-NG instrument and its present
status are described. We have demonstrated this year that most of the
technical challenges have been successfully faced and the next steps
are mentioned. We then recall the scientific questions that might
be solved with the next generation of instruments in construction
in different european laboratories to reach a complete 3D vision of
our star from the core to the corona. Two formation flying missions
DynaMICCS and HIRISE have been proposed to ESA in the framework of
the 2015-2025 Cosmic Vision perspective to contribute to solve these
questions. A strategy of measurements must be found for the next decade.

---------------------------------------------------------
Title: AsteroFLAG — from the Sun to the stars
Authors: Chaplin, W. J.; Appourchaux, T.; Arentoft, T.; Ballot, J.;
Baudin, F.; Bazot, M.; Bedding, T. R.; Christensen-Dalsgaard, J.;
Creevey, O. L.; Duez, V.; Elsworth, Y.; Fletcher, S. T.; García,
R. A.; Gough, D. O.; Jiménez, A.; Jiménez-Reyes, S. J.; Houdek, G.;
Kjeldsen, H.; Lazrek, M.; Leibacher, J. W.; Monteiro, M. J. P. F. G.;
Neiner, C.; New, R.; Régulo, C.; Salabert, D.; Samadi, R.; Sekii,
T.; Sousa, S. G.; Toutain, T.; Turck-Chièze, S.
2008JPhCS.118a2048C Altcode:
We stand on the threshold of a critical expansion of asteroseismology
of Sun-like stars, the study of stellar interiors by observation
and analysis of their global acoustic modes of oscillation. The
Sun-like oscillations give a very rich spectrum allowing the internal
structure and dynamics to be probed down into the stellar cores to
very high precision. Asteroseismic observations of many stars will
allow multiple-point tests of crucial aspects of stellar evolution
and dynamo theory. The aims of the asteroFLAG collaboration are to
help the community to refine existing, and to develop new, methods
for analysis of the asteroseismic data on the Sun-like oscillators.

---------------------------------------------------------
Title: The Rotation of the Solar Radiative zone
Authors: Turck-Chieze, S.
2008IAUS..252..257T Altcode:
Dynamical processes are progressively introduced in stellar
evolution. In this framework, the Sun is a very specific case where
both models and observations have been developed in parallel during the
last decade in order to progress on our present insight of solar like
stars. In this poster I show the recent progress done on both sides for
the rotation of the radiative zone. The present knowledge of the solar
rotation profile comes from the detection of acoustic and gravity modes
with the instruments GOLF and MDI aboard SoHO. In parallel we study
the sensitivity of the theoretical rotation profiles obtained with
the CESAM code using different rotation history in the premainsequence.

---------------------------------------------------------
Title: Update on g-mode research
Authors: García, R. A.; Jiménez, A.; Mathur, S.; Ballot, J.;
Eff-Darwich, A.; Jiménez-Reyes, S. J.; Pallé, P. L.; Provost, J.;
Turck-Chièze, S.
2008AN....329..476G Altcode: 2008arXiv0802.4296G
Since the beginning of this century we have attended a blooming
of the gravity-mode research thanks to the unprecedented quality
of the data available, either from space with SoHO, or from the
ground-based networks as BiSON or GONG. From the first upper limit
of the gravity-mode amplitudes fixed at 10 mm/s at 200 μHz given
by Appourchaux et al. (2000), on one hand, a peak was supposed
to be a component of the ℓ = 1, n = 1 mixed mode (García et
al. 2001a, 2001b; Gabriel et al. 2002) and, on the other hand, a
couple of patterns - multiplets - were attributed to gravity modes
(Turck-Chièze et al. 2004; Mathur et al. 2007). One of these patterns,
found around 220 μHz, could be labeled as the ℓ = 2, n =-3 g mode,
which is expected to be the one with the highest surface amplitude
(Cox &amp; Guzik 2004). Finally, in 2007, García et al. were able to
measure the fingertips of the dipole gravity modes looking for their
asymptotic properties. In the present paper we present an update of the
recent developments on this subject with special attention to the 220
μHz region, the dipole asymptotic properties and the impact of the
incoming g-mode observations on the knowledge of the solar structure
and rotation profile.

---------------------------------------------------------
Title: Sensitivity of helioseismic gravity modes to the dynamics of
the solar core
Authors: Mathur, S.; Eff-Darwich, A.; García, R. A.; Turck-Chièze, S.
2008A&A...484..517M Altcode: 2008arXiv0803.3966M
Context: The dynamics of the solar core cannot be properly constrained
through the analysis of acoustic oscillation modes. Gravity modes
(g modes) are necessary to understand the structure and dynamics
of the deepest layers of the Sun. Through recent progress on the
observation of these modes - both individually and collectively -
new information is available to contribute to inferring the rotation
profile inside the nuclear burning core. Aims: We aim to see the
sensitivity of gravity modes to the rotation of the solar core. We
analyze the influence of adding the splitting of one and several g
modes to the data sets used in helioseismic numerical inversions. We
look for constraints on the uncertainties required in the observations
to improve the derived core rotation profile. Methods: We compute
three artificial sets of splittings derived for three rotation profiles:
a rigid profile taken as a reference; a step-like profile and a smoother
profile with higher rates in the core. We compute inversions based
on regularized least-squares methodology (RLS) for both artificial
data with real error bars and real data. Several sets of data are
used: first, we invert only acoustic modes (p modes), then we add
one and several g modes to which different values of observational
uncertainties (75 and 7.5 nHz) are attributed. For the real data,
we include g-mode candidate, ℓ=2, n=-3 with several splittings and
associated uncertainties. Results: We show that the introduction
of one g mode in artificial data improves the rate in the solar core and
gives an idea of the tendency of the rotation profile. The addition of
more g modes lends greater accuracy to the inversions and stabilizes
them. The inversion of real data with the g-mode candidate gives a
rotation profile that remains unchanged down to 0.2 R⊙,
whatever value of splitting we attribute to the g mode.

---------------------------------------------------------
Title: Laboratory performances of the solar multichannel resonant
scattering spectrometer prototype of the GOLF-New Generation
instrument
Authors: Turck-Chièze, S.; Carton, P. H.; Mathur, S.; Barrière,
J. -C.; Daniel-Thomas, P.; Lahonde-Hamdoun, C.; Granelli, R.; Loiseau,
D.; Nunio, F.; Piret, Y.; Robillot, J. M.
2008AN....329..521T Altcode: 2008arXiv0806.3521T
This article quickly summarizes the performances and results of
the GOLF/SoHO resonant spectrometer, thus justifying to go a step
further. We then recall the characteristics of the multichannel resonant
GOLF-NG spectrometer and present the first successful performances of
the laboratory tests on the prototype and also the limitations of this
first technological instrument. Scientific questions and an observation
strategy are discussed.

---------------------------------------------------------
Title: Asteroseismology of Procyon with SOPHIE
Authors: Mosser, B.; Bouchy, F.; Martić, M.; Appourchaux, T.; Barban,
C.; Berthomieu, G.; Garcia, R. A.; Lebrun, J. C.; Michel, E.; Provost,
J.; Thévenin, F.; Turck-Chièze, S.
2008A&A...478..197M Altcode: 2007arXiv0712.1368M
Context: This paper reports a 9-night asteroseismic observation
program conducted in January 2007 with the new spectrometer sophie
at the OHP 193-cm telescope, on the F5 IV-V target Procyon A. Aims: This first asteroseismic program with sophie was intended
to test the performance of the instrument with a bright but demanding
asteroseismic target and was part of a multisite network. Methods:
The sophie spectra have been reduced with the data reduction software
provided by OHP. The Procyon asteroseismic data were then analyzed
with statistical tools. The asymptotic analysis has been conducted
considering possible curvature in the échelle diagram analysis. Results: These observations have proven the efficient performance of
sophie used as an asteroseismometer, and succeed in a clear detection
of the large spacing. An échelle diagram based on the 54-μHz
spacing shows clear ridges. Identification of the peaks exhibits
large spacings varying from about 52 μHz to 56 μHz. Outside
the frequency range [0.9, 1.0 mHz] where the identification is
confused, the large spacing increases at a rate of about dΔν/dn
≃ 0.2 μHz. This may explain some of the different values of
the large spacing obtained by previous observations. Based on
observations collected with the sophie échelle spectrometer mounted
on the 1.93-m telescope at OHP, France (program 06B.PNPS.BOU);
http://www.obs-hp.fr/www/guide/ sophie/sophie-eng.html Table of
radial velocity measurements 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/478/197

---------------------------------------------------------
Title: Influence of a global magnetic field on stellar structure
Authors: Duez, V.; Brun, A. S.; Mathis, S.; Nghiem, P. A. P.;
Turck-Chièze, S.
2008MmSAI..79..716D Altcode:
The theoretical framework we have developed to take into account
the influence of a global axisymmetric magnetic field on stellar
structure and evolution is described. The prescribed field, possibly
time-dependent, is expanded in the vectorial spherical harmonics
basis. Hydrostatic equilibrium and energetic balance are consequently
modified. Convection's efficiency and onset are also revised. Finally,
our numerical strategy and the results one can expect from the
implementation of those theoretical results are discussed.

---------------------------------------------------------
Title: The dynamics of the solar radiative zone
Authors: Turck-Chièze, Sylvaine; Talon, Suzanne
2008AdSpR..41..855T Altcode:
The picture of the solar radiative zone is evolving quickly. This
review is separated in two parts. We first recall how the two powerful
probes of the solar interior, namely the neutrinos and helioseismology
have scrutinized the microscopic properties of the solar radiative
plasma. Recent observations stimulate today complementary activities
beyond the standard stellar model through theoretical modeling of
angular momentum transport by rotation, internal waves or (and)
by magnetic fields to get access to the dynamical motions of this
important region of the Sun. So in the second part, we summarize the
first impact of such processes on the radiative zone.

---------------------------------------------------------
Title: Meridional circulation in the radiation zones of rotating
stars: Origins, behaviors and consequences on stellar evolution
Authors: Mathis, S.; Decressin, T.; Palacios, A.; Eggenberger, P.;
Siess, L.; Talon, S.; Charbonnel, C.; Turck-Chièze, S.; Zahn, J. -P.
2007AN....328.1062M Altcode:
Stellar radiation zones are the seat of meridional currents. This
circulation has a strong impact on the transport of angular momentum
and the mixing of chemicals that modify the evolution of stars. First,
we recall in details the dynamical processes that are taking place in
differentially rotating stellar radiation zones and the assumptions
which are adopted for their modelling in stellar evolution. Then, we
present our new results of numerical simulations which allow us to
follow in 2D the secular hydrodynamics of rotating stars, assuming
that anisotropic turbulence enforces a shellular rotation law and
taking into account the transport of angular momentum by internal
gravity waves. The different behaviors of the meridional circulation
in function of the type of stars which is studied are discussed with
their physical origin and their consequences on the transport of
angular momentum and of chemicals. Finally, we show how this work is
leading to a dynamical vision of the evolution of rotating stars from
their birth to their death.

---------------------------------------------------------
Title: Division XI / Wg: Particle Astrophysics
Authors: Schlickeiser, Reinhard; Blandford, Roger D.; Brillet, Alain;
Fujimoto, Masa-Katsu; Madau, Piero; Olinto, Angela V.; Salvati, Marco;
Schutz, Bernard F.; Smith, Peter F.; Spiro, Michel; Stepanyan, Arnold
A.; Totsuka, Yoji; Turck-Chieze, Sylvaine; Voelk, Heinrich J.
2007IAUTB..26..207S Altcode:
The business meeting of the Division XI Working Group on Particle
Astrophysics took place in the morning of 25 August 2006, and was
attended by 14 participants.

---------------------------------------------------------
Title: Simulations of Turbulent Convection in Rotating Young Solarlike
Stars: Differential Rotation and Meridional Circulation
Authors: Ballot, Jérôme; Brun, Allan Sacha; Turck-Chièze, Sylvaine
2007ApJ...669.1190B Altcode: 2007arXiv0707.3943B
We present the results of three-dimensional simulations of the deep
convective envelope of a young (10 Myr) 1 Msolar star,
obtained with the anelastic spherical harmonic code. Since young stars
are known to be faster rotators than their main-sequence counterparts,
we have systematically studied the impact of the stellar rotation
speed, by considering stars spinning up to 5 times as fast as the
Sun. The aim of these nonlinear models is to understand the complex
interactions between convection and rotation. We discuss the influence
of the turbulence level and of the rotation rate on the intensity
and the topology of the mean flows. For all of the computed models,
we find a solar-type superficial differential rotation, with an
equatorial acceleration, and meridional circulation that exhibits a
multicellular structure. Even if the differential rotation contrast
ΔΩ decreases only marginally for high rotation rates, the meridional
circulation intensity clearly weakens according to our simulations. We
have also shown that, for Taylor numbers above a certain threshold
(Ta&gt;~109), the convection can develop a vacillating
behavior. Since simulations with high turbulence levels and rotation
rates exhibit strongly cylindrical internal rotation profiles, we
have considered the influence of baroclinic effects at the base of the
convective envelope of these young Suns to see whether such effects can
modify the otherwise near-cylindrical profiles to produce more conical,
solarlike profiles.

---------------------------------------------------------
Title: VizieR Online Data Catalog: Procyon (alpha CMi) radial
velocities (Mosser+, 2008)
Authors: Mosser, B.; Bouchy, F.; Martic, M.; Appourchaux, T.; Barban,
C.; Berthomieu, G.; Garcia, R. A.; Lebrun, J. C.; Michel, E.; Provost,
J.; Thevenin, F.; Turck-Chieze, S.
2007yCat..34780197M Altcode:
Time series of the radial velocities of Procyon recorder with the
echelle spectrometer SOPHIE at Observatoire de Haute Provence in
January 2007. (1 data file).

---------------------------------------------------------
Title: On the Characteristics of the Solar Gravity Mode Frequencies
Authors: Mathur, S.; Turck-Chièze, S.; Couvidat, S.; García, R. A.
2007ApJ...668..594M Altcode:
Gravity modes are the best probes for studying the dynamics of the solar
radiative zone, and especially the nuclear core. This paper shows how
specific physical processes influence the theoretical g-mode frequencies
for the l=1 and l=2 modes over a large range of radial orders n from
-46 to -1, corresponding to potential SOHO observations. To this end,
we compute different solar models, and we calculate the corresponding
theoretical g-mode frequencies. These frequencies are sensitive to
the physical inputs of our solar models in the high-frequency range
of the oscillation power spectrum. At low frequency, we demonstrate
that the periodic spacing (ΔPl) between two g-modes
with consecutive orders n and with the same angular degree l does
not vary significantly from one model to the other. For all the
models considered, including models based on recent solar chemical
abundances, the value of the characteristic quantity P0,
the fundamental period of the g-modes, is constant within a 1 minute
range (between 34 and 35 minutes). This result is in sharp contrast
to the situation before the launch of the SOHO spacecraft, when the
dispersion for P0 was large (with values ranging from 29
to 60 minutes). Then, we estimate the sensitivity of the oscillation
frequency splittings to the solar core rotation. Finally, we review some
features of the g-mode observations obtained with the GOLF instrument
and based on an almost complete solar cycle. Some of these help us
constrain the excitation mechanisms of g-modes.

---------------------------------------------------------
Title: Dynamical processes in the subsurface layers of the Sun
Authors: Lefebvre, S.; Nghiem, P.; Turck-Chièze, S.
2007sf2a.conf..586L Altcode:
Recent results obtained by Lefebvre and Kosovichev (2005) using f-modes
frequencies from SOHO/MDI, indicate a change in the stratification of
the subsurface layers, more precisely a non-homogeneous variation of
these layers with depth and time. To progress on this transition zone
between the solar interior and the external part, we begin to analyse
the problem from a theoretical point of view. Using the CESAM code,
we show how a small variation in the radius implies a variation in the
subsurface structure. We use the theoretical f-modes frequencies to
examine the corresponding changes in the stratification. Furthermore,
we discuss the related physics, very complex in this zone, and show
the variations of the temperature gradients, the density and pressure
scale heights caused by the change in radius.

---------------------------------------------------------
Title: Review of the GOLF/SOHO helioseismic results and Perspectives
Authors: Turck-Chièze, S.; GOLF Team; GOLF-Ng Team; Dynamics Teams
2007sf2a.conf..623T Altcode:
Helioseismic measurements aboard SoHO deliver new facts useful to
improve our understanding of Sun and stars. After more than a decade
of measurements aboard SoHO, we present the helioseismic results
obtained with the GOLF instrument. If the first published papers
of this community have mainly contrained the internal microphysics,
these last 5 years have revealed an unprecedent insight on the impact
of the solar cycle on the outer layers thanks to acoustic modes and
on the radiative zone dynamics thanks to gravity mode studies. We will
show why GOLF appears as an excellent instrument for this purpose and
what we have learned from 10 years of observation aboard SoHO with this
french-spanish resonant spectrometer. The progress done today by Doppler
velocity measurements aboard SoHO (GOLF+ MDI) and by ground networks
(BiSON and GONG) opens a totally new perspective for solar and stellar
physics. So we then mention the questions that might be solved with the
next generation of instruments already in construction in different
european laboratories including GOLF-NG. They lead to two formation
flying missions DynaMICCS and HIRISE proposed in the framework of the
ESA Cosmic Vision perspective. An european strategy of measurements
is suggested to maintain this discipline in the best conditions for
the two next decades in order to get quantitative estimate of the
effective role of the solar variabilities along time.

---------------------------------------------------------
Title: Tracking Solar Gravity Modes: The Dynamics of the Solar Core
Authors: García, Rafael A.; Turck-Chièze, Sylvaine; Jiménez-Reyes,
Sebastian J.; Ballot, Jérôme; Pallé, Pere L.; Eff-Darwich, Antonio;
Mathur, Savita; Provost, Janine
2007Sci...316.1591G Altcode:
Solar gravity modes have been actively sought because they directly
probe the solar core (below 0.2 solar radius), but they have not
been conclusively detected in the Sun because of their small surface
amplitudes. Using data from the Global Oscillation at Low Frequency
instrument, we detected a periodic structure in agreement with the
period separation predicted by the theory for gravity dipole modes. When
studied in relation to simulations including the best physics of the
Sun determined through the acoustic modes, such a structure favors a
faster rotation rate in the core than in the rest of the radiative zone.

---------------------------------------------------------
Title: Probing the internal solar magnetic field through g modes
Authors: Rashba, T. I.; Semikoz, V. B.; Turck-Chièze, S.; Valle,
J. W. F.
2007MNRAS.377..453R Altcode: 2006astro.ph.11728R; 2007MNRAS.tmp..249R
The observation of g-mode candidates by the Solar and Heliospheric
Observatory (SOHO) mission opens the possibility of probing the
internal structure of the solar radiative zone (RZ) and the solar core
more directly than possible via the use of the p-mode helioseismology
data. We study the effect of rotation and RZ magnetic fields on g-mode
frequencies. Using a self-consistent static magnetohydrodynamics
magnetic field model, we show that a 1 per cent g-mode frequency shift
with respect to the Solar Seismic Model (SSEM) prediction, currently
hinted in the Global Oscillation at Low Frequencies (GOLF) data, can
be obtained for magnetic fields as low as 300 kG, for current measured
modes of radial order n = -20. On the other hand, we also argue that
a similar shift for the case of the low-order g-mode candidate (l =
2, n = -3) frequencies cannot result from rotation effects nor from
central magnetic fields, unless these exceed 8 MG.

---------------------------------------------------------
Title: Understanding the origin of the solar cyclic activity for an
improved earth climate prediction
Authors: Turck-Chièze, Sylvaine; Lambert, Pascal
2007AdSpR..40..907T Altcode:
This review is dedicated to the processes which could explain the origin
of the great extrema of the solar activity. We would like to reach a
more suitable estimate and prediction of the temporal solar variability
and its real impact on the Earth climatic models. The development of
this new field is stimulated by the SoHO helioseismic measurements
and by some recent solar modelling improvement which aims to describe
the dynamical processes from the core to the surface. We first recall
assumptions on the potential different solar variabilities. Then, we
introduce stellar seismology and summarize the main SOHO results which
are relevant for this field. Finally we mention the dynamical processes
which are presently introduced in new solar models. We believe that the
knowledge of two important elements: (1) the magnetic field interplay
between the radiative zone and the convective zone and (2) the role of
the gravity waves, would allow to understand the origin of the grand
minima and maxima observed during the last millennium. Complementary
observables like acoustic and gravity modes, radius and spectral
irradiance from far UV to visible in parallel to the development of
1D-2D-3D simulations will improve this field. PICARD, SDO, DynaMICCS
are key projects for a prediction of the next century variability. Some
helioseismic indicators constitute the first necessary information to
properly describe the Sun-Earth climatic connection.

---------------------------------------------------------
Title: Advances in Secular Magnetohydrodynamics of Stellar Interiors
Dedicated to Asteroseismic Spatial Missions
Authors: Mathis, S.; Eggenberger, P.; Decressin, T.; Palacios, A.;
Siess, L.; Charbonnel, C.; Turck-Chièze, S.; Zahn, J. -P.
2007EAS....26...65M Altcode: 2007astro.ph..3117M
With the first light of COROT, the preparation of KEPLER and the future
helioseismology spatial projects such as GOLF-NG, a coherent picture
of the evolution of rotating stars from their birth to their death is
needed. We describe here the modelling of the macroscopic transport of
angular momentum and matter in stellar interiors that we have undertaken
to reach this goal. First, we recall in detail the dynamical processes
that are driving these mechanisms in rotating stars and the theoretical
advances we have achieved. Then, we present our new results of numerical
simulations which allow us to follow in 2D the secular hydrodynamics
of rotating stars, assuming that anisotropic turbulence enforces a
shellular rotation law. Finally, we show how this work is leading to
a dynamical vision of the Hertzsprung-Russel diagram with the support
of asteroseismology and helioseismology, seismic observables giving
constraints on the modelling of the internal transport and mixing
processes. In conclusion, we present the different processes that
should be studied in the near future to improve our description of
stellar radiation zones.

---------------------------------------------------------
Title: The Seismology Programme of CoRoT
Authors: Michel, E.; Baglin, A.; Auvergne, M.; Catala, C.; Aerts,
C.; Alecian, G.; Amado, P.; Appourchaux, T.; Ausseloos, M.; Ballot,
J.; Barban, C.; Baudin, F.; Berthomieu, G.; Boumier, P.; Bohm, T.;
Briquet, M.; Charpinet, S.; Cunha, M. S.; De Cat, P.; Dupret, M. A.;
Fabregat, J.; Floquet, M.; Fremat, Y.; Garrido, R.; Garcia, R. A.;
Goupil, M. -J.; Handler, G.; Hubert, A. -M.; Janot-Pacheco, E.;
Lambert, P.; Lebreton, Y.; Lignieres, F.; Lochard, J.; Martin-Ruiz,
S.; Mathias, P.; Mazumdar, A.; Mittermayer, P.; Montalban, J.;
Monteiro, M. J. P. F. G.; Morel, P.; Mosser, B.; Moya, A.; Neiner,
C.; Nghiem, P.; Noels, A.; Oehlinger, J.; Poretti, E.; Provost, J.;
Renan de Medeiros, J.; De Ridder, J.; Rieutord, M.; Roca-Cortes, T.;
Roxburgh, I.; Samadi, R.; Scuflaire, R.; Suarez, J. C.; Theado, S.;
Thoul, A.; Toutain, T.; Turck-Chieze, S.; Uytterhoeven, K.; Vauclair,
G.; Vauclair, S.; Weiss, W. W.; Zwintz, K.
2006ESASP1306...39M Altcode: 2008arXiv0811.1080M
We introduce the main lines and specificities of the CoRoT Seismology
Core Programme. The development and consolidation of this programme has
been made in the framework of the CoRoT Seismology Working Group. With a
few illustrative examples, we show how CoRoT data will help to address
various problems associated with present open questions of stellar
structure and evolution.

---------------------------------------------------------
Title: The DynaMICS perspective
Authors: Turck-Chièze, S.; Schmutz, W.; Thuillier, G.; Jefferies,
S.; Pallé; Dewitt, S.; Ballot, J.; Berthomieu, G.; Bonanno, A.;
Brun, A. S.; Christensen-Dalsgaard, J.; Corbard, T.; Couvidat, S.;
Darwich, A. M.; Dintrans, B.; Domingo, V.; Finsterle, W.; Fossat,
E.; Garcia, R. A.; Gelly, B.; Gough, D.; Guzik, J.; Jiménez, A. J.;
Jiménez-Reyes, S.; Kosovichev, A.; Lambert, P.; Lefebvre, S.; Lopes,
I.; Martic, M.; Mathis, S.; Mathur, S.; Nghiem, P. A. P.; Piau, L.;
Provost, J.; Rieutord, M.; Robillot, J. M.; Rogers, T.; Roudier, T.;
Roxburgh, I.; Rozelot, J. P.; Straka, C.; Talon, S.; Théado, S.;
Thompson, M.; Vauclair, S.; Zahn, J. P.
2006ESASP.624E..24T Altcode: 2006soho...18E..24T
No abstract at ADS

---------------------------------------------------------
Title: Sensitivity of the predicted frequencies of l = 1 gravity
modes to known physical processes
Authors: Mathur, S.; Turck-Chièze, S.; Couvidat, S.; Garcia, R. A.
2006ESASP.624E..95M Altcode: 2006soho...18E..95M
No abstract at ADS

---------------------------------------------------------
Title: Comparison of the solar velocity spectrum from MDI and GOLF
during cycle 23
Authors: Lefebvre, S.; García, R. A.; Jiménez-Reyes, S. J.;
Turck-Chièze, S.
2006ESASP.624E..94L Altcode: 2006soho...18E..94L
No abstract at ADS

---------------------------------------------------------
Title: Dynamical processes in the solar radiative interior
Authors: Palacios, A.; Talon, S.; Turck-Chièze, S.; Charbonnel, C.
2006ESASP.624E..38P Altcode: 2006soho...18E..38P; 2006astro.ph..9381P
Recent seismic observations coming from acoustic and gravity modes
clearly show that the solar standard model has reached its limits
and can no longer be used to interpret satisfactorily seismic
observations. In this paper, we present a review of the non-standard
processes that may be added to the solar models in order to improve
our understanding of the helioseismic data. We also present some
results obtained when applying “non-standard” stellar evolution to
the modelling of the Sun.

---------------------------------------------------------
Title: Procyon-A and Bootis: observational frequencies analyzed by
the local-wave formalism
Authors: Nghiem, P. A. P.; Ballot, J.; García, R. A.; Lambert, P.;
Turck-Chièze, S.
2006ESASP.624E.116N Altcode: 2006astro.ph..8652N; 2006soho...18E.116N
In the present analysis of Procyon-A and Eta-Bootis, we use the
local-wave formalism which, despite its lack of precision inherent to
any semi-analytical method, uses directly the model profile without any
modification when calculating the acoustic mode eigenfrequencies. These
two solar-like stars present steep variations toward the center due
to the convective core stratification, and toward the surface due to
the very thin convective zone. Based on different boundary conditions,
the frequencies obtained with this formalism are different from that
of the classical numerical calculation. We point out that (1) the
frequencies calculated with the local-wave formalism seem to agree
better with observational ones. All the frequencies detected with a
good confident level including those classified as 'noise' find an
identification, (2) some frequencies can be clearly identified here
as indications of the core limit.

---------------------------------------------------------
Title: Cyclic variability of the seismic solar radius from SOHO/MDI
and related physics
Authors: Lefebvre, S.; Kosovichev, A. G.; Nghiem, P.; Turck-Chièze,
S.; Rozelot, J. P.
2006ESASP.624E...9L Altcode: 2006soho...18E...9L
No abstract at ADS

---------------------------------------------------------
Title: Detection of periodic signatures in the solar power spectrum
On the track of l=1 gravity modes
Authors: García, R. A.; Turck-Chièze, S.; Jiménez-Reyes, S. J.;
Ballot, J.; Pallé, P. L.; Eff-Darwich, A.; Mathur, S.; Provost, J.
2006ESASP.624E..23G Altcode: 2006astro.ph.11806G; 2006soho...18E..23G
In the present work we show robust indications of the existence
of g modes in the Sun using 10 years of GOLF data. The present
analysis is based on the exploitation of the collective properties
of the predicted low-frequency (25 to 140 microHz) g modes: their
asymptotic nature, which implies a quasi equidistant separation of
their periods for a given angular degree (l). The Power Spectrum (PS)
of the Power Spectrum Density (PSD), reveals a significant structure
indicating the presence of features (peaks) in the PSD with near
equidistant periods corresponding to l=1 modes in the range n=-4 to
n=-26. The study of its statistical significance of this feature was
fully undertaken and complemented with Monte Carlo simulations. This
structure has a confidence level better than 99.86% not to be due to
pure noise. Furthermore, a detailed study of this structure suggests
that the gravity modes have a much more complex structure than the one
initially expected (line-widths, magnetic splittings...). Compared to
the latest solar models, the obtained results tend to favor a solar
core rotating significantly faster than the rest of the radiative
zone. In the framework of the Phoebus group, we have also applied the
same methodology to other helioseismology instruments on board SoHO
and ground based networks.

---------------------------------------------------------
Title: The internal structure of the Sun inferred from g modes and
low-frequency p modes
Authors: Elsworth, Y. P.; Baudin, F.; Chaplin, W; Andersen, B;
Appourchaux, T.; Boumier, P.; Broomhall, A. -M.; Corbard, T.;
Finsterle, W.; Fröhlich, C.; Gabriel, A.; García, R. A.; Gough,
D. O.; Grec, G.; Jiménez, A.; Kosovichev, A.; Provost, J.; Sekii,
T.; Toutain, T.; Turck-Chièze, S.
2006ESASP.624E..22E Altcode: 2006soho...18E..22E
The Phoebus group is an international collaboration of
helioseismologists, its aim being to detect low-frequency solar g
modes. Here, we report on recent work, including the development and
application of new techniques based on the detection of coincidences
in contemporaneous datasets and the asymptotic properties of the g-mode
frequencies. The length of the time series available to the community is
now more than ten years, and this has reduced significantly the upper
detection limits on the g-mode amplitudes. Furthermore, low-degree p
modes can now be detected clearly at frequencies below 1000 μHz.

---------------------------------------------------------
Title: On the possible existence of localised vacillating convection
state in rapidly rotating young solar-like stars
Authors: Ballot, J.; Brun, A. S.; Turck-Chièze, S.
2006ESASP.624E.108B Altcode: 2006soho...18E.108B
No abstract at ADS

---------------------------------------------------------
Title: Dynamical processes in stellar radiation zones
Authors: Mathis, S.; Decressin, T.; Palacios, A.; Siess, L.;
Charbonnel, C.; Turck-Chièze, S.; Zahn, J. -P.
2006IAUJD..17E..18M Altcode:
With the progress of asteroseismology, we need a coherent picture of
the evolution of rotating stars from their birth to their death. We
describe here the modelling of the macroscopic transport of matter
and angular momentum in stellar interiors that we have undertaken to
achieve this goal. First, we briefly recall the dynamical processes
that are driving these mechanisms in rotating stars. Then, we present
our new results of numerical simulations which allow us to follow in 2D
the secular hydrodynamics of rotating stars, assuming that anisotropic
turbulence enforces a cellular rotation law. We discuss the different
processes such as MHD instabilities that should be studied in the next
future to improve our description of dynamical processes in stellar
radiation zones. Finally, we show how our new results are leading
us to a dynamical vision of Hertzsprung-Russell diagram, in support
of asteroseismology.

---------------------------------------------------------
Title: Knowledge of the solar core dynamics through g modes
Authors: Garcia, R. A.; Turck-Chièze, S.; Jimenez-Reyes, S. J.;
Ballot, J.; Pallé, P. L.; Eff-Darwich, A.; Mathur, S.; Provost, J.
2006IAUJD..17E...8G Altcode:
Helioseismology is able to study the solar interior through the
observation of the solar oscillation modes propagating inside the
Sun. Pressure-driven modes (p modes) provide a very detailed picture
of the external convective zone above 0.7 R[⊙]and the radiative zone
down to ~0.2 R[⊙] where only a few of such modes penetrate so far. To
study deeper layers, still containing more than 40% of the totals mass,
another type of oscillations are needed: the gravity-driven modes
(g modes). Since the early 19 80s, this type of mode has been looked
for. Only very recently have we have found some structures that are
compatible with some global properties of these modes in the GOLF/ SOHO
data. In this contribution we will show these signals. By explaining
them as the signature of the asymptotic properties of the ℓ = 1 g
modes, we could start constraining the solar core dynamics.

---------------------------------------------------------
Title: The DynaMICS project
Authors: Garcia, R.; Turck-Chièze, S.
2006IAUJD..17E..33G Altcode:
The DynaMICS (Dynamics and Magnetism from the Internal core to
the Chromosphere of the Sun) space project is devoted to the long
term (decades or centuries) global properties of the Sun. Its main
scientific objectives are the following: (1) to get a complete 3D
rotating and magnetic picture of the Sun from the central core up to the
chromosphere, (2) to deduce from it the different sources of dynamos
and their interplay, (3) to build models and predictions of the great
maxima and minima solar activities, (4) to produce outputs useful to
quantify the different aspects of the solar contribution to the Earth's
climate. We outline here the instruments: GOLFNG, SODISM, PREMOS, MOF
that we are developing to reach this goal. They will detect from space
solar acoustic and gravity modes together with radius and irradiance
variations and will improve our knowledge on the transition region
between photosphere and chromosphere. Understanding the magnetic field
of the radiative zone is a new and crucial objective, as this ingredient
must play a role in the long-term Sun-Earth relationship and also in
the knowledge of stellar interiors. These instruments will observe
the Sun from an orbit around the Lagrangian L[1] point for a decade
to ensure continuity, stability and measurements of tiny variations.

---------------------------------------------------------
Title: Curvelet analysis of asteroseismic data. I. Method description
and application to simulated sun-like stars
Authors: Lambert, P.; Pires, S.; Ballot, J.; García, R. A.; Starck,
J. -L.; Turck-Chièze, S.
2006A&A...454.1021L Altcode: 2006astro.ph..4092L
Context: .The detection and identification of oscillation modes (in
terms of their ℓ, m, and successive n) is a great challenge for
present and future asteroseismic space missions. "Peak tagging" is an
important step in the analysis of these data to provide estimations of
stellar oscillation mode parameters, i.e., frequencies, rotation rates,
and further studies on the stellar structure. Aims: .Our goal
is to increase the signal-to-noise ratio of the asteroseismic spectra
computed from the time series that are representative of MOST and CoRoT
observations (30- and 150-day observations). Methods: .We apply
the curvelet transform - a recent image processing technique that looks
for curved patterns - to echelle diagrams built using asteroseismic
power spectra. In the resulting diagram, the eigenfrequencies appear
as smooth continuous ridges. To test the method, we use Monte-Carlo
simulations of several sun-like stars with different combinations
of rotation rates, rotation-axis inclination, and signal-to-noise
ratios. Results: .The filtered diagrams enhance the contrast
between the ridges of the modes and the background, allowing a
better tagging of the modes and a better extraction of some stellar
parameters. Monte-Carlo simulations have also shown that the region
where modes can be detected is enlarged at lower and higher frequencies
compared to the raw spectra. In addition, the extraction of the mean
rotational splitting from modes at low frequency can be done more
easily using the filtered spectra rather than the raw spectra.

---------------------------------------------------------
Title: Scientific Objectives of the Novel Formation Flying Mission
Aspiics
Authors: Turck-Chièze, S.; Schmutz, W.; Thuillier, G.; Jefferies,
S.; Pallé; Dewitt, S.; Ballot, J.; Berthomieu, G.; Bonanno, A.;
Brun, A. S.; Christensen-Dalsgaard, J.; Corbard, T.; Couvidat, S.;
Darwich, A. M.; Dintrans, B.; Domingo, V.; Finsterle, W.; Fossat,
E.; Garcia, R. A.; Gelly, B.; Gough, D.; Guzik, J.; Jiménez, A. J.;
Jiménez-Reyes, S.; Kosovichev, A.; Lambert, P.; Lefebvre, S.; Lopes,
I.; Martic, M.; Mathis, S.; Mathur, S.; Nghiem, P. A. P.; Piau, L.;
Provost, J.; Rieutord, M.; Robillot, J. M.; Rogers, T.; Roudier, T.;
Roxburgh, I.; Rozelot, J. P.; Straka, C.; Talon, S.; Théado, S.;
Thompson, M.; Vauclair, S.; Zahn, J. P.
2006ESASP.617E.164L Altcode: 2006soho...17E.164L
No abstract at ADS

---------------------------------------------------------
Title: The EUV Variability Experiment (EVE) on the Solar Dynamics
Observatory (SDO): Science Plan and Instrument Overview
Authors: Turck-Chièze, S.; Schmutz, W.; Thuillier, G.; Jefferies,
S.; Pallé; Dewitt, S.; Ballot, J.; Berthomieu, G.; Bonanno, A.;
Brun, A. S.; Christensen-Dalsgaard, J.; Corbard, T.; Couvidat, S.;
Darwich, A. M.; Dintrans, B.; Domingo, V.; Finsterle, W.; Fossat,
E.; Garcia, R. A.; Gelly, B.; Gough, D.; Guzik, J.; Jiménez, A. J.;
Jiménez-Reyes, S.; Kosovichev, A.; Lambert, P.; Lefebvre, S.; Lopes,
I.; Martic, M.; Mathis, S.; Mathur, S.; Nghiem, P. A. P.; Piau, L.;
Provost, J.; Rieutord, M.; Robillot, J. M.; Rogers, T.; Roudier, T.;
Roxburgh, I.; Rozelot, J. P.; Straka, C.; Talon, S.; Théado, S.;
Thompson, M.; Vauclair, S.; Zahn, J. P.
2006ESASP.617E.165W Altcode: 2006soho...17E.165W
No abstract at ADS

---------------------------------------------------------
Title: Detection of the Periodic Signatures of l=1 Solar g Modes
with 10 Years of GOLF/SOHO Data
Authors: Garcia, Rafael A.; Turck-Chiéze, Sylvaine; Jiménez-Reyes,
Sebastián J.; Ballot, Jerome; Palle, Pere L.; Eff-Darwich, Antonio;
Mathur, Savita; Provost, Janine
2006ESASP.617E...3G Altcode: 2006soho...17E...3G
No abstract at ADS

---------------------------------------------------------
Title: Recent Progresses on g-Mode Search
Authors: Appourchaux, T.; Andersen, B.; Baudin, F.; Boumier, P.;
Broomhall, A. -M.; Chaplin, W.; Corbard, T.; Elsworth, Y.; Finsterle,
W.; Fröhlich, C.; Gabriel, A.; Garcia, R.; Gough, D. O.; Grec, G.;
Jiménez, A.; Kosovichev, A.; Provost, J.; Sekii, T.; Toutain, T.;
Turck-Chièze, S.
2006ESASP.617E...2A Altcode: 2006soho...17E...2A
No abstract at ADS

---------------------------------------------------------
Title: Dynamics of the Solar Radiative Zone: Present and Future
Authors: Turck-Chièze, S.
2006ESASP.617E..39T Altcode: 2006soho...17E..39T
No abstract at ADS

---------------------------------------------------------
Title: The Dynamics Project
Authors: Turck-Chièze, S.; Schmutz, W.; Thuillier, G.; Jefferies,
S.; Pallé; Dewitt, S.; Ballot, J.; Berthomieu, G.; Bonanno, A.;
Brun, A. S.; Christensen-Dalsgaard, J.; Corbard, T.; Couvidat, S.;
Darwich, A. M.; Dintrans, B.; Domingo, V.; Finsterle, W.; Fossat,
E.; Garcia, R. A.; Gelly, B.; Gough, D.; Guzik, J.; Jiménez, A. J.;
Jiménez-Reyes, S.; Kosovichev, A.; Lambert, P.; Lefebvre, S.; Lopes,
I.; Martic, M.; Mathis, S.; Mathur, S.; Nghiem, P. A. P.; Piau, L.;
Provost, J.; Rieutord, M.; Robillot, J. M.; Rogers, T.; Roudier, T.;
Roxburgh, I.; Rozelot, J. P.; Straka, C.; Talon, S.; Théado, S.;
Thompson, M.; Vauclair, S.; Zahn, J. P.
2006ESASP.617E.162T Altcode: 2006soho...17E.162T
No abstract at ADS

---------------------------------------------------------
Title: Dynamical processes in stellar radiation zones: secular
magnetohydrodynamics of rotating stars
Authors: Mathis, S.; Decressin, T.; Palacios, A.; Siess, L.;
Charbonnel, C.; Turck-Chièze, S.; Zahn, J. -P.
2006sf2a.conf..491M Altcode:
With the imminent launch of COROT and the preparation of new
helioseismology instruments such as GOLF-NG (cf. DynaMICS project), we
need a coherent picture of the evolution of rotating stars from their
birth to their death. We describe here the modeling of the macroscopic
transport of angular momentum and matter in stellar interiors that we
have undertaken to achieve this goal. First, we recall the dynamical
processes that are driving this transport in rotating stars and the
theoretical advances we have accomplished. Then, we present our new
results of numerical simulations which allow us to follow in 2D the
secular hydrodynamics of rotating stars, assuming that anisotropic
turbulence enforces a shellular rotation law. Finally, we show how
this work is leading to a dynamical vision of the Hertzsprung-Russel
diagram in support of asteroseismology and helioseismology.

---------------------------------------------------------
Title: Solar gravity modes: Present and future
Authors: Turck-Chièze, Sylvaine
2006AdSpR..37.1569T Altcode: 2005astro.ph.11126T
Gravity modes are the best probes to study the solar radiative zone
dynamics, especially in the nuclear core. These modes remain difficult
to observe, but they are essential ingredients for progressing
on the evolution of the Sun-Earth relationship at the level of
centuries. Today, the knowledge of the internal dynamics comes from
acoustic modes and concerns mainly the external 2% of the solar
mass. Nevertheless, the flat rotation profile of the radiative zone
compels physics beyond the standard framework. I summarize different
attempts to look for gravity modes and the results obtained after
8 years of observation with the GOLF/SoHO instrument. Some gravity
mode candidates (at 1 mm/s level) have appeared with more than 98%
confidence level as quadruplets or quintuplets. These patterns, if
confirmed as gravity modes, may reveal very exciting physics of the
solar core. Getting information on rotation and magnetic field in
the solar core are real keys to simulate a complete dynamical solar
picture. The understanding of the solar dynamics, the precise energetic
balance and its temporal evolution necessitate more observations
of the radiative zone which constitutes 98% of the Sun by mass. Our
expertise in Doppler velocity measurements allows a step further and
a new instrumental concept to reach velocities as low as 0.1 mm/s. A
prototype will join the Tenerife site in 2006 and a space version is
proposed to CNES and ESA as a microsatellite or part of a payload at
the L1 Lagrange point.

---------------------------------------------------------
Title: GOLF-NG spectrometer, a space prototype for studying the
dynamics of the deep solar interior
Authors: Turck-Chièze, Sylvaine; Carton, Pierre-Henri; Ballot,
Jérome; Barrière, Jean-Christophe; Daniel-Thomas, Philippe; Delbart,
Alain; Desforges, Daniel; Garcia, Rafaël A.; Granelli, Rémi; Mathur,
Savita; Nunio, François; Piret, Yves; Pallé, Pere L.; Jiménez,
Antonio J.; Jiménez-Reyes, Sebastian J.; Robillot, Jean Maurice;
Fossat, Eric; Eff-Darwich, Antonio. M.; Gelly, Bernard
2006AdSpR..38.1812T Altcode: 2005astro.ph.10753T
The GOLF-NG (Global Oscillations at Low Frequency New Generation)
instrument is devoted to the search for solar gravity and acoustic
modes, and also chromospheric modes from space. This instrument which
is a successor to GOLF/SOHO will contribute to improve our knowledge
of the dynamics of the solar radiative zone. It is a 15 points resonant
scattering spectrometer, working on the D1 sodium line. A ground-based
prototype is under construction to validate the difficult issues. It
will be installed at the Teide Observatory, on Tenerife in 2006 to
analyse the separation of the effects of the magnetic turbulence of
the line from the solar oscillations. We are prepared to put a space
version of this instrument including a capability of identification of
the modes, in orbit during the next decade. This instrument should be
included in the ILWS program as it offers a key to the improvement of
our knowledge of the solar core in combination with observations from
SDO and PICARD. We hope to determine the core rotation and magnetic
field, through precise measurements of oscillation mode frequency
splittings. Understanding the magnetic field of the radiative zone
is important for progress in the study of solar activity sources,
an important player for the long-term Sun-Earth relationship.

---------------------------------------------------------
Title: The origin of the solar cyclic activities: the DynaMICS project
Authors: Turck-Chieze, S.; Brun, A. S.; Garcia, R. A.; Jiménez-Reyes,
S. J.; Palle, P.; Dynamics Team
2006cosp...36.2001T Altcode: 2006cosp.meet.2001T
In order to better estimate the earth climatic variations at scales
corresponding to decennia or centuries it appears more and more
important to understand the internal origin of the solar magnetic
cyclic activities together with the evolution of the internal solar
rotation profile It is the only way to be able to predict how they
will evolve in the future The seismic techniques are totally adapted
to this knowledge and an enriched information will allow to interpret
the solar global variations as irradiance luminosity at different
wavelengths and will measure temporal global mode characteristics which
must be linked to the total magnetic fluxes ldots Our main objectives
are to predict the characteristics of the coming solar cycles and to
determine if there is different origins for the longer solar cycles or
if it is only a temporal evolution of the eleven cycle 22 years which
produces grand minima or maxima SDO is well adapted to progress on the
convective zone with increased resolution in comparison with the SoHO
mission it will allow to improve the 11 year solar cycle predictions In
complementarity we consider very important to get a general description
of the dynamics of the solar radiative zone which contains the main
part of the solar mass and to understand the interconnection between
magnetic fields of the radiative zone and of the convective zones Such
information stays today poorly known even SoHO results on the solar
radiative zone through acoustic and gravity modes are very promising
to pursue this investigation In this

---------------------------------------------------------
Title: GOLF New Generation: a spectrophotometer for the quest of
solar gravity modes
Authors: Turck-Chièze, S.; Mathur, S.; Carton, P. H.; García, R. A.;
Palle, P.; Ballot, J.
2005sf2a.conf..167T Altcode:
The Global Oscillations at Low Frequency: New Generation instrument
(GOLF-NG), the successor of GOLF aboard SoHO, is devoted to the study
the dynamics of the solar radiative zone thanks to the detection of
solar gravity modes and low-frequency acoustic modes. This instrument
built under a French-Spanish collaboration, is based on the Doppler
velocity method using a 15 points resonant scattering spectrometer
working on the D1 sodium line and will be placed in Tenerife. The
observations of the space version called DynaMICS (for Dynamics and
Magnetism of the Innner Core of the Sun) will enable us to improve
our knowledge of the radiative zone, especially the solar core and the
influence of the Sun on our planet by the determination of the origin
of the magnetic activities. The investigation of the sodium line will
also provide interesting information on the atmosphere of the Sun,
between the photosphere and the chromosphere.

---------------------------------------------------------
Title: The magnetism of the solar interior for a complete MHD
solar vision
Authors: Turck-Chièze, S.; Appourchaux, T.; Ballot, J.; et al.
2005ESASP.588..193T Altcode: 2005astro.ph.10854T; 2005tssc.conf..193T
The solar magnetism is no more considered as a purely superficial
phenomenon. The SoHO community has shown that the length of the
solar cycle depends on the transition region between radiation and
convection. Nevertheless, the internal solar (stellar) magnetism
stays poorly known. Starting in 2008, the American instrument HMI/SDO
and the European microsatellite PICARD will enrich our view of the
Sun-Earth relationship. Thus obtaining a complete MHD solar picture is
a clear objective for the next decades and it requires complementary
observations of the dynamics of the radiative zone. For that ambitious
goal, space prototypes are being developed to improve gravity mode
detection. The Sun is unique to progress on the topology of deep
internal magnetic fields and to understand the complex mechanisms which
provoke photospheric and coronal magnetic changes and possible longer
cycles important for human life. We propose the following roadmap in
Europe to contribute to this "impressive" revolution in Astronomy and
in our Sun-Earth relationship: SoHO (1995-2007), PICARD (2008-2010),
DynaMICS (2009-2017) in parallel to SDO (2008-2017) then a world-class
mission located at the L1 orbit or above the solar poles.

---------------------------------------------------------
Title: The life of stars and their planets
Authors: Catala, C.; Aerts, C.; Aigrain, S.; Antonello, E.;
Appourchaux, T.; Auvergne, M.; Baglin, A.; Barge, P.; Barstow, M. A.;
Baudin, F.; Boumier, P.; Collier Cameron, A.; Christensen-Dalsgaard,
J.; Cutispoto, G.; Deeg, H.; Deleuil, M.; Desidera, S.; Donati, J. -F.;
Favata, F.; Foing, B. H.; Gameiro, J. F.; Garcia, R.; Garrido, F.;
Horne, K.; Lanza, A. F.; Lanzafame, A. C.; Lecavelier Des Etangs,
A.; Léger, A.; Mas-Hesse, M.; Messina, S.; Micela, G.; Michel, E.;
Monteiro, M. J. P. F. G.; Mosser, B.; Noels, A.; Pagano, I.; Piotto,
G.; Poretti, E.; Rauer, H.; Roca-Cortes, T.; Rodono, M.; Rouan, D.;
Roxburgh, I.; Schneider, J.; Strassmeier, K.; Turck-Chièze, S.;
Vauclair, S.; Vidal-Madjar, A.; Weiss, W. W.; Wheatley, P.
2005ESASP.588...99C Altcode: 2005tssc.conf...99C
We lack a reliable scenario for the formation and evolution of stars
and their planetary systems, involving key factors such as magnetic
fields and turbulence. We present the case for a mission concept that
will clarify these problems and give us a global view of the evolution
of combined star and planetary systems. This will be achieved by
simultaneously addressing the search for planetary transits in front
of a large number of stars, including many nearby stars, the study of
their internal structure and evolution via asteroseismology, and that
of their magnetic activity, via UV monitoring.

---------------------------------------------------------
Title: Global solar Doppler velocity determination with the GOLF/SoHO
instrument
Authors: García, R. A.; Turck-Chièze, S.; Boumier, P.; Robillot,
J. M.; Bertello, L.; Charra, J.; Dzitko, H.; Gabriel, A. H.;
Jiménez-Reyes, S. J.; Pallé, P. L.; Renaud, C.; Roca Cortés, T.;
Ulrich, R. K.
2005A&A...442..385G Altcode:
The Global Oscillation at Low Frequencies (GOLF) experiment is
a resonant scattering spectrophotometer on board the Solar and
Heliospheric Observatory (SoHO) mission, originally designed to measure
the disk-integrated solar oscillations of the Sun. This instrument was
designed in a relative photometric mode involving both wings of the
neutral sodium doublet (D1 at λ 5896 and D2 at
λ 5890 Å). However, a "one-wing" photometric mode has been selected
to ensure 100% continuity in the measurements after a problem in the
polarization mechanisms. Thus the velocity is obtained from only two
points on the same wing of the lines. This operating configuration
imposes tighter constraints on the stability of the instrument with a
higher sensitivity to instrumental variations. In this paper we discuss
the evolution of the instrument during the last 8 years in space and
the corrections applied to the measured counting rates due to known
instrumental effects. We also describe a scaling procedure to obtain
the variation of the Doppler velocity based on our knowledge of the
sodium profile slope and we compare it to previous velocity estimations.

---------------------------------------------------------
Title: Solar models and solar neutrinos
Authors: Turck-Chièze, S.
2005NuPhS.145...17T Altcode:
I present the orientations of these last years to build a more complete
picture of the Sun. This direction leads us to compare results from
solar models (standard and not standard) to recent observations of the
solar interior. We use the seismic results to build seismic models and
deduce new neutrino predictions, including recent updated composition
and nuclear reaction rates. Today, we get a coherent view of the Sun
through the two totally independent approaches: helioseismology and
neutrino detected fluxes. This is extremely promising for preparing
the second step: to go beyond the standard framework of stellar
evolution. So, I discuss also the perspectives for the next 5 years
which will be crucial years and must lead to the discovery of new
neutrino properties.

---------------------------------------------------------
Title: How does helioseismology constrain solar neutrino properties?
Authors: Turck-Chièze, S.
2005NuPhS.143...35T Altcode:
This review summarizes the advances in solar modelling due to
helioseismic measurements. One objective is the correct determination
of the different neutrino fluxes and the establishment of the first
neutrino properties. The two solar probes (acoustic modes and detected
neutrinos) are today in excellent agreement after introduction of
the LMA solution for the neutrino oscillations. This consistency is
impressive and confirms the interest to look to neutrinos of the
Universe. We note that the introduction of recent improvements on
essential ingredients of solar modelling put in evidence the limitation
of the “Solar Standard Model”. Discrepancies between its results
and solar observations are rich of physics beyond this framework,
with evident perspectives to look for other neutrino properties,
in pursuing the investigation of different objects of the Universe
including the Sun.

---------------------------------------------------------
Title: Seismic constraints on open clusters
Authors: Piau, L.; Ballot, J.; Turck-Chièze, S.
2005A&A...430..571P Altcode: 2005astro.ph..3157P
The aim of this theoretical and modelling paper is to derive knowledge
on the global and structural parameters of low-mass stars using
asteroseismology and taking advantage of the stellar collective
behavior within open clusters. We build stellar models and compute
the seismic signal expected from main sequence objects in the 0.8-1.6
M⊙ range. We first evaluate apparent magnitudes and
oscillations-induced luminosity fluctuations expected in the Hyades,
the Pleiades and the α Persei clusters. The closest cluster presents
a feasible challenge to observational asteroseismology in the present
and near future. The remainder of the work therefore focuses on the
Hyades. We combine seismological and classical computations to address
three questions: what can be inferred about 1) mass; 2) composition;
and 3) extension of outer convection zones of solar analogs in the
Hyades. The first issue relies on the strong sensitivity of the large
separation to mass. We show that seismic constraints provide masses to
a precision level (0.05 M⊙) that is competitive with the
actual mass estimations from binary systems. Then large separations (Δ
ν) and second differences (δ2 ν) are used to respectively
constrain metal and helium fractions in the Hyades. When plotted for
several masses, the relation of effective temperature (Teff)
vs. large separation (Δ ν) is found to be strongly dependent on the
metal content. Besides this the second difference main modulation is
related to the second ionization of helium. An accuracy in the helium
mass fraction of 0.02 to 0.01 can be achieved provided mass and age are
accurately known, which is the case for a few Hyades binary systems. The
second difference modulations are also partly due to the discontinuity
in stellar stratification at the convective envelope/radiative core
transition. They permit direct insight in the stellar structure. We
compute acoustic radii of the convective bases for different values
of the mixing length theory parameter αMLT in convection
modelling, i.e. different convective efficiency in the superadiabatic
layers. For a given effective temperature we show that the acoustic
radius changes with convection efficiency. This suggests that seismology
can provide constraints on the extension of outer convection and also
more generally on the direct approaches of convection and dynamical
phenomena being currently developed.

---------------------------------------------------------
Title: MeV Neutrino Sources: The Sun and the Supernovae
Authors: Turck-Chièze, Sylvaine
2005HiA....13....9T Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Quiet or Active Sun and the Neutrino Properties
Authors: Turck-Chieze, S.
2005ppls.conf...45T Altcode:
The Sun and the Supernovae are very interesting MeV neutrino sources
and remarkable examples of symbiosis between astrophysics and particle
physics researches. Thanks to helioseismology, we have now reached a
clear characterization of the solar central plasma and consequently,
we put strong constraints on the solar core temperature. We deduce a
prediction of the most energetic neutrino fluxes with a high degree of
confidence. Neutrino detections have also solved challenging questions,
as the detection of the different flavors of neutrinos. The present
impressive agreement between prediction of the seismic solar model
and SNO detection leads to an unambiguous evidence for a solution of
the neutrino puzzle and a clear demonstration of the presence of solar
neutrino oscillations. It is now worth to notice that the main role of
seismology is to build a dynamical view of the stellar interiors. The
description of the magneto-hydrodynamical processes is nowadays the
present objective for a renewal of the stellar discipline. This year,
important results on the Sun constitute a real breakthrough towards
a dynamical vision of the Sun from which we may hope to extract
complementary solar neutrino properties. I comment here on the real
interest to look for other neutrino properties with the solar source
of neutrinos and give preliminary results.

---------------------------------------------------------
Title: Challenges in Stellar Models from Helioseismology to
Asteroseismology
Authors: Turck-Chièze, Sylvaine; Phi Nghiem, Phu Anh; Piau, Laurent
2005HiA....13..403T Altcode:
Stellar evolution is improving very quickly thanks to precise
observations and the introduction of hydrodynamical processes. These
phenomena improve our vision of stars in the phases where they have
a dominant role. I shall present some challenging problems choosen
in young clusters high mass stars or final stages of evolution. Helio and asteroseismology will largely contribute to validate
our understanding of the dynamical aspects which are not totally
undercontrolled with present computer performances. The Sun is the
crucial guide for developping tools useful for future space missions. I
shall introduce the difficulties and highlights of this unique case when
we look to the Sun as a star. This experience is extremely rich for
the future asteroseismic observations. Some strategies of observation
will be introduced to disentangle the validation of physical processes
from the waiting asteroseismic observation difficulties.

---------------------------------------------------------
Title: Helioseismology, Neutrinos and Radiative Zones
Authors: Turck-Chièze, S.; Couvidat, S.; Piau, L.
2005EAS....17..149T Altcode: 2005astro.ph.11008T
The solar interior has been scrutinized by two different and independent
probes during the last twenty years with important revisions of the
solar model, including a recent heavy element abundance revision. Today,
we get a quantitatively coherent picture (even incomplete) of the solar
(stellar) radiative zones. In this review, we recall the clues for
solar gravitational settling definitively established by the seismic
determination of the photospheric helium content. We comment also
on the need for mixing in the transition region between radiation and
convection in the case of the Sun and of population II stars. We finally
list the open questions and the importance to continue more precise
investigations of the solar (stellar) radiative zone in detecting
gravity modes with the project DynaMICS.

---------------------------------------------------------
Title: The solar radiative interior: gravity modes and future
instrumentation
Authors: Garcia, R. A.; Turck-Chieze, S.; Ballot, J.; Couvidat, S.;
Eff-Darwich, A.; Jiménez-Reyes, S. J.; Mathur, S.; Pallé, P. L.;
GOLF-Ng Team
2004sf2a.conf...99G Altcode: 2004sf2a.confE.281G
Today, the knowledge of the solar radiative interior is obtained by the
solar acoustic modes. Thanks to the latest modes detected by SoHO the
sound speed has been determined down to 0.06 Ro with a resolution of
3%. This profile is used to improve the solar model and its deviations
from a static vision. The rotation profile is now clearly established
down to the limit of the core (Garcia et al. 2004). In order to progress
toward the core and reduce the uncertainties in the radiative region,
gravity modes should be measured. Recently, Turck-Chieze et al. (2004)
have identified some patterns using GOLF data during the last solar
minimum, that can be interpreted in terms of gravity modes. These
candidates, with an amplitude of ~2 mm/s, are at the limit of the
signal-to-noise ratio and are difficult to follow when the activity
increases. Their research will continue until the end of the SoHO
lifetime in 2008 during the next solar minimum. In the best case,
only a few mixed and gravity modes will be detected with SoHO. This
is the reason why a French-Spanish collaboration is now building a
prototype of a new spatial instrument, GOLF-NG, that will be tested
during the Summer 2005 in the Observatorio del Teide. GOLF-NG will
directly address the problem of the solar convective background noise
to improve the g-mode detection.

---------------------------------------------------------
Title: Astroseismology in open clusters
Authors: Piau, Laurent; Ballot, Jerome; Turck-Chieze, Sylvaine
2004sf2a.conf..319P Altcode: 2004sf2a.confE.299P
The surface oscillations of solar-like stars provide precious
informations on their global characteristics (mass, composition) and
structure. The open-clusters reveal particularly interesting in this
respect. We have built stellar models of Hyades stars for different
masses and plausible ages and compositions of this cluster. Several
seismic quantities were subsequently evaluated. I will address
the question of performances necessary to complete precise seismic
observations for solar-like Hyades. Then I will present our prospective
work in asteroseismology and I will show how the analysis of the
collective seismic effects can improve our knowledge on these stars. For
instance the relation between the acoustic radius of the inner radiative
core and the effective temperature reveals extremely sensitive to
the convective efficiency in the superadiabatic layers. This relation
should allow to set constraints on convective efficiency and therefore
on the hydrodynamical simulations of convection.

---------------------------------------------------------
Title: Turbulent Convection in Young Solar-like Stars: Influence
of rotation
Authors: Ballot, J.; Brun, A. S.; Turck-Chièze, S.
2004sf2a.conf..197B Altcode: 2004sf2a.confE.266B
The study of the relationship between X-ray emission and rotation in
young stars (Feigelson et al. 2003) and observations of magnetic-field
topology of such stars with Zeeman-Doppler Imaging (Donati et al. 2003)
indicate that the dynamo processes differ from those operating in main
sequence stars. In this context, 3-D numerical simulations have been
started. The first step is to study the purely hydrodynamic case. We
have simulated the convective shell of a young sun (10 Myr) with the
Anelastic Spherical Harmonic (ASH) code. We have studied the angular
momentum transfer, the meridional circulation and the differential
rotation in this shell. We have also studied the effects of different
rotation rates (1, 2 and 5 solar rate).

---------------------------------------------------------
Title: Surprising Sun: A New Step Towards a Complete Picture?
Authors: Turck-Chièze, S.; Couvidat, S.; Piau, L.; Ferguson, J.;
Lambert, P.; Ballot, J.; García, R. A.; Nghiem, P.
2004PhRvL..93u1102T Altcode: 2004astro.ph..7176T
Important revisions of the solar model ingredients have appeared
recently. We first show that the updated CNO composition suppresses the
anomalous position of the Sun in the known galactic enrichment. The
following law, He/H=0.075+44.6 O/H in number fraction, is now
compatible with all the indicators. We then suggest some directions
of investigation to solve the discrepancies between the standard
model and solar seismic observations. We finally update our
predicted neutrino fluxes using a seismic model and all the recent
progress. We get 5.31±0.6×106/cm2/s for the
total 8B neutrinos, 66.5±4.4 SNU and 2.76±0.4 SNU for the
gallium and chlorine detectors, all in remarkable agreement with the
detected values including neutrino oscillations for the last two. So,
the acoustic modes and detected neutrinos see the same Sun, but the
standard model fails to reproduce them.

---------------------------------------------------------
Title: Global Magnetic Field Strength at Solar Surface: Mean Value
and Variations with the Activity Cycle
Authors: Nghiem, P. A. P.; García, R. A.; Turck-Chièze, S.;
Jiménez-Reyes, S. J.
2004ESASP.559..577N Altcode: 2004soho...14..577N
No abstract at ADS

---------------------------------------------------------
Title: Gravity Modes with a Resonant Scattering Spectrophotometer
Authors: Turck-Chièze, S.; Garcia, R. A.; Couvidat, S.; Ballot, J.;
Jiménez-Reyes, S. J.; Fossat, E.; Gelly, B.; Mathur, S.; Nghiem,
P. A. P.; Pallé, P.; Robillot, Jm.; GOLF-Ng Technical Team
2004ESASP.559...85T Altcode: 2004soho...14...85T
No abstract at ADS

---------------------------------------------------------
Title: Solar Low-Degree P-Mode Parameters after 8 Years of Velocity
Measurements with SOHO
Authors: García, R. A.; Jiménez-Reyes, S. J.; Turck-Chièze, S.;
Ballot, J.; Henney, C. J.
2004ESASP.559..436G Altcode: 2004soho...14..436G
No abstract at ADS

---------------------------------------------------------
Title: Helioseismology from the Blue and Red Wings of the NA Profile
as Seen by GOLF
Authors: García, R. A.; Jiménez-Reyes, S. J.; Turck-Chièze, S.;
Mathur, S.
2004ESASP.559..432G Altcode: 2004soho...14..432G
No abstract at ADS

---------------------------------------------------------
Title: Seismic extraction of the convective extent in solar-like
stars. The observational point of view
Authors: Ballot, J.; Turck-Chièze, S.; García, R. A.
2004A&A...423.1051B Altcode:
Convection is the first manifestation of macroscopic motions in
stars. In the next decade, the extent of the external convective zone
of solar-like stars will have to be derived from the eigenfrequencies
of their low-degree (ℓ=0,1 and 2) acoustic modes. In this paper,
we compare different tracers of the base of the convective zone
(BCZ) and show that the second difference δ2ν stays
simple and well suited for analyzing real data. We suggest the
use of \tilde{t}BCZ=(2&lt;Δν&gt;)-1 -
\tilde{τ}BCZ as a quasi-non-biased indicator of the BCZ
acoustic radius. The method is first checked on a long-time solar
observation with GOLF, then on shorter real observations by VIRGO and
10 000 simulated observations of solar-like stars. We present results
for different observational duration and stellar masses. The intrinsic
error due to the method on the convective extent is smaller than 1.5%
(in units of stellar acoustic radius) for stars with masses between
0.9 and 1.3 M⊙. The limited observational interval
adds a supplementary uncertainty of about 1.6% for a 150-day long
simulated observation. In this study, we have also analyzed the
effects of stochastic excitation and of non-continuous runs of
shorter lengths. We discuss how to take into account the variations
in activity. Appendix B is only available in electronic form at
http://www.edpsciences.org

---------------------------------------------------------
Title: Erratum: “Looking for Gravity-Mode Multiplets with the GOLF
Experiment aboard SOHO” (<A href="/abs/2004ApJ...604..455T">ApJ,
604, 455 [2004]</A>)
Authors: Turck-Chièze, S.; García, R. A.; Couvidat, S.; Ulrich,
R. K.; Bertello, L.; Varadi, F.; Kosovichev, A. G.; Gabriel, A. H.;
Berthomieu, G.; Brun, A. S.; Lopes, I.; Pallé, P.; Provost, J.;
Robillot, J. M.; Roca Cortés, T.
2004ApJ...608..610T Altcode:
As a result of an error at the Press, the second panel of Figure 9
was repeated twice in the top row of the printed, black-and-white
version of this figure, and the first panel was omitted. This error
appears in the print edition and the PDF and postscript (PS) versions
available with the electronic edition of the journal, although the
panels of the color figure displayed in the electronic article itself
are correct. Please see below for the corrected print version of Figure
9. The Press sincerely regrets the error.

---------------------------------------------------------
Title: Dynamical Processes Induced by the Internal Solar Rotation
Authors: Turck-Chièze, S.
2004IAUS..215..317T Altcode:
No abstract at ADS

---------------------------------------------------------
Title: About the rotation of the solar radiative interior
Authors: García, R. A.; Corbard, T.; Chaplin, W. J.; Couvidat, S.;
Eff-Darwich, A.; Jiménez-Reyes, S. J.; Korzennik, S. G.; Ballot,
J.; Boumier, P.; Fossat, E.; Henney, C. J.; Howe, R.; Lazrek, M.;
Lochard, J.; Pallé, P. L.; Turck-Chièze, S.
2004SoPh..220..269G Altcode:
In the modern era of helioseismology we have a wealth of high-quality
data available, e.g., more than 6 years of data collected by the various
instruments on board the SOHO mission, and an even more extensive
ground-based set of observations covering a full solar cycle. Thanks
to this effort a detailed picture of the internal rotation of the Sun
has been constructed. In this paper we present some of the actions
that should be done to improve our knowledge of the inner rotation
profile discussed during the workshop organized at Saclay on June 2003
on this topic. In particular we will concentrate on the extraction of
the rotational frequency splittings of low- and medium-degree modes
and their influence on the rotation of deeper layers. Furthermore,
for the first time a full set of individual |m|-component rotational
splittings is computed for modes ℓ≤4 and 1&lt;ν&lt;2 mHz, opening
new studies on the latitudinal dependence of the rotation rate in the
radiative interior. It will also be shown that these splittings have
the footprints of the differential rotation of the convective zone
which can be extremely useful to study the differential rotation of
other stars where only these low-degree modes will be available.

---------------------------------------------------------
Title: Looking for Gravity-Mode Multiplets with the GOLF Experiment
aboard SOHO
Authors: Turck-Chièze, S.; García, R. A.; Couvidat, S.; Ulrich,
R. K.; Bertello, L.; Varadi, F.; Kosovichev, A. G.; Gabriel, A. H.;
Berthomieu, G.; Brun, A. S.; Lopes, I.; Pallé, P.; Provost, J.;
Robillot, J. M.; Roca Cortés, T.
2004ApJ...604..455T Altcode:
This paper is focused on the search for low-amplitude solar gravity
modes between 150 and 400 μHz, corresponding to low-degree, low-order
modes. It presents results based on an original strategy that looks
for multiplets instead of single peaks, taking into consideration
our knowledge of the solar interior from acoustic modes. Five years
of quasi-continuous measurements collected with the helioseismic GOLF
experiment aboard the SOHO spacecraft are analyzed. We use different
power spectrum estimators and calculate confidence levels for the
most significant peaks. This approach allows us to look for signals
with velocities down to 2 mm s-1, not far from the limit
of existing instruments aboard SOHO, amplitudes that have never been
investigated up to now. We apply the method to series of 1290 days,
beginning in 1996 April, near the solar cycle minimum. An automatic
detection algorithm lists those peaks and multiplets that have a
probability of more than 90% of not being pure noise. The detected
patterns are then followed in time, considering also series of 1768 and
2034 days, partly covering the solar cycle maximum. In the analyzed
frequency range, the probability of detection of the multiplets
does not increase with time as for very long lifetime modes. This is
partly due to the observational conditions after 1998 October and the
degradation of these observational conditions near the solar maximum,
since these modes have a “mixed” character and probably behave as
acoustic modes. Several structures retain our attention because of
the presence of persistent peaks along the whole time span. These
features may support the idea of an increase of the rotation in the
inner core. There are good arguments for thinking that complementary
observations up to the solar activity minimum in 2007 will be decisive
for drawing conclusions on the presence or absence of gravity modes
detected aboard the SOHO satellite.

---------------------------------------------------------
Title: Solar gravity modes: the present and future
Authors: Turck-Chièze, S.; Garcià, R.; Fossat, E.; Gelly, B.; Palle,
P.; Robillot, Jm; Golf-Ng
2004cosp...35.3949T Altcode: 2004cosp.meet.3949T
Gravity modes are the best probes to study the solar radiative zone,
in particular the nuclear core and to follow its potential variability
with time and latitude. Nevertheless, their amplitude is small and
the solar noise particularly high in the range of frequency where
they stand (below 500 μ Hz). It is why they are looked for more than
20 years and actively serached with GOLF and MDI instruments aboard
SoHO which offers the best conditions of observation. Some candidates
(Turck-Chièze et al. 2004) have been identified in the GOLF instrument,
during the period of low solar activity thanks to an original research
of multiplets corresponding to surface amplitudes of about 2mm/s. The
examination of the interesting frequency range (100 to 400 μ Hz) will
be pursued up to the end of the SoHO mission scheduled for 2007. Today
our knowledge of the radiative zone is due to acoustic modes. Recent
clear progress is due to the detection of modes less influenced by
the sun activity, in the range 400-1600 μ Hz. The sound speed is
determined down to 0.06 Ro with a resolution of 3%. This profile
is used to improve the solar model and its deviations from a static
vision. The rotation profile is now clearly established down to the
limit of the core and its rigidity can only be explained by invoking
a magnetic field effect. We present here GOLF-NG (Turck-Chièze et
al., 2000) built by a French Spanish collaboration to improve g-mode
detection. Based on the Doppler velocity method using a resonant
spectrometer with a 16 channels on the sodium line, the main objective
of GOLF-NG is to contribute to get an MHD picture of the Sun to better
understand the influence of the Sun on earth climate, in improving
the detection by a factor 10 in decreasing the solar noise thanks
to a variable magnet. Consequently, the physical information will be
extracted at different heights in the atmosphere. A prototype will be
installed in 2005 in Tenerife. Then a spatial version will be available
for taking place in one project of the ILWS mission. Turck-Chièze,
S., Robillot, J.M., Dzitko, H ., Boumier, P., Decaudin, M., Gabriel,
A.H., Garcia, R.A., Grec, G., Pallé, P.L., Renaud, C., Schmidt, D.,
2000, ESA SP-464, 331; Turck-Chieze, S., Garcia, R.A., Couvidat, S.,
et al., 2004, ApJ, vol 604,

---------------------------------------------------------
Title: The Sun as a reference for Eddington
Authors: Turck-Chièze, S.
2004ESASP.538...95T Altcode: 2004sshp.conf...95T
In this review, I point out the major achievements of the helioseismic
community on the physical description of the solar interior and the
related efforts which must be performed to reach a corresponding
scientific return in asteroseismology with the Eddington mission. I
comment on the characteristics of the low degree modes which are the
only modes accessible to this mission. Using solar data obtained with
the resonant spectrometer GOLF and with the photometric instrument
VIRGO onboard SoHO, I recall the importance of the duration of the
observations and of the mode characteristics for the determination
of internal indicators. This work takes into account the role of
stochastic excitation and of solar activity. From all these remarks,
I deduce some points which should be discussed during the Eddington
preparation phase, in order to guarantee good observations and to
prepare for rapid interpretations after launch.

---------------------------------------------------------
Title: A possible method for detecting a convective core
Authors: Nghiem, P. A. P.; Ballot, J.; Piau, L.; Turck-Chièze, S.
2004ESASP.538..377N Altcode: 2004sshp.conf..377N
Intermediate mass stars feature a convective core which is
often confined in less than 10% of their radius. That implies a
sound speed discontinuity at the core edge, which is seen in the
eigenfrequencies. But, because of the very deep location, the classical
use of the second difference fails to detect it. We propose here to look
directly at the large separation, for the modes whose internal turning
points are around the discontinuity. This method is first tested with
the Sun to detect the discontinuity. This method is first tested with
the Sun to detect the discontinuity at the base of the convection zone,
with degrees l = 20 to 50. Then it is applied to intermediate mass
stars using low-degree modes l &lt; 3 to explore the signature of a
convective core. The example of α Centauri A is given. The evolution
of the radiative core of young stars is also studied.

---------------------------------------------------------
Title: The solar neutrino puzzle
Authors: Couvidat, S.; Turck-Chieze, S.
2004frun.conf..191C Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Solar gravity modes: the present and future
Authors: Turck-Chièze, S.; Garcià, R.; Fossat, E.; Gelly, B.; Palle,
P.; Robillot, Jm
2004cosp...35.3946T Altcode: 2004cosp.meet.3946T
Gravity modes are the best probes to study the solar radiative zone,
in particular the nuclear core and to follow its potential variability
with time and latitude. Nevertheless, their amplitude is small and
the solar noise particularly high in the range of frequency where
they stand (below 500 μ Hz). It is why they are looked for more than
20 years and actively serached with GOLF and MDI instruments aboard
SoHO which offers the best conditions of observation. Some candidates
(Turck-Chièze et al. 2004) have been identified in the GOLF instrument,
during the period of low solar activity thanks to an original research
of multiplets corresponding to surface amplitudes of about 2mm/s. The
examination of the interesting frequency range (100 to 400 μ Hz) will
be pursued up to the end of the SoHO mission scheduled for 2007. Today
our knowledge of the radiative zone is due to acoustic modes. Recent
clear progress is due to the detection of modes less influenced by the
sun activity, in the range 400-1600 μ Hz. The sound speed is determined
down to 0.06 Ro with a resolution of 3%. This profile is used to improve
the solar model and its deviations from a static vision. The rotation
profile is now clearly established down to the limit of the core and its
rigidity can only be explained by invoking a magnetic field effect. We
present here GOLF-NG (Turck-Chièze et al., 2000) built by a French
Spanish collaboration to improve g-mode detection. Based on the Doppler
velocity method using a resonant spectrometer with a 16 channels on
the sodium line, the main objective of GOLF-NG is to contribute to
get an MHD picture of the Sun to better understand the influence of
the Sun on earth climate, in improving the detection by a factor 10 in
decreasing the solar noise thanks to a variable magnet. Consequently,
the physical information will be extracted at different heights in the
atmosphere. A prototype will be installed in 2005 in Tenerife. Then a
spatial version will be available for taking place in one project of the
ILWS mission. Turck-Chièze, S., Robillot, J.M., Dzitko, H ., Boumier,
P., Decaudin, M., Gabriel, A.H., Garcia, R.A., Grec, G., Pallé, P.L.,
Renaud, C., Schmidt, D., 2000, ESA SP-464, 331; Turck-Chièze, S.,
Garcia, R.A., Couvidat, S., et al., 2004, ApJ, vol 604,

---------------------------------------------------------
Title: Extraction of the convective zone extension from solar-like
stars
Authors: Ballot, J.; García, R. A.; Turck-Chièze, S.
2004ESASP.538..265B Altcode: 2004sshp.conf..265B
The aim of this study is to estimate the quality of the asteroseismic
observations for 150 days of photometric measurements. We have
used simulated data and VIRGO time series as a good example of a
one-solar-mass Eddington target. From the extracted-mode frequencies we
have tried to measure the position of the base of the convective zone
(BCZ). We have studied the two following cases: in the first one, the
observation is done during five consecutive months; in the second,
we use five non-consecutive one-month observations. The effects of
the stochastic excitation and the stellar activity on the frequency
determination are studied and discussed. In this framework we are also
developing a new semi-automatic algorithm to extract low-degree mode
parameters without any a priori.

---------------------------------------------------------
Title: Solar Seismic Models and the Neutrino Predictions
Authors: Couvidat, S.; Turck-Chièze, S.; Kosovichev, A. G.
2003ApJ...599.1434C Altcode: 2002astro.ph..3107C
This paper focuses on the solar neutrino fluxes, the g-mode predictions,
and the possible impact of the magnetic fields on the neutrino emission
and transport. The Solar and Heliospheric Observatory (SOHO) spacecraft
has allowed astrophysicists to achieve a major breakthrough in the
knowledge of the solar core. Both GOLF and MDI instruments on SOHO
have significantly improved the accuracy of the sound speed profile,
mainly by the detection of low-degree low-order p-modes. Our study
(Turck-Chièze and coworkers) has lead to precise neutrino predictions
through constructing a seismic solar model that is in good agreement
with the sound speed profile inferred by helioseismology in the
radiative interior of the Sun. In this paper we present the details
of this study and investigate new solar models validated by the
acoustic modes. These new models are primarily used to derive the
emitted neutrino fluxes. We show that these fluxes do not depend
strongly on the modified physics as far as the model is consistent
with the helioseismic observations in the core. We also show that an
internal large-scale magnetic field cannot exceed a maximum strength
of ~=3×107 G in the radiative zone and may increase the
emitted 8B neutrino flux only by ~=2%. All the neutrino
predictions here are compatible with the Sudbury Neutrino Observatory
results, assuming three neutrino flavors. We deduce the electron and
neutron radial densities that are needed to calculate the neutrino
oscillation properties. Finally, we discuss how the magnetic fields
may influence the neutrino transport through the RSFP process, for
different values of Δm2.

---------------------------------------------------------
Title: The Rotation of the Deep Solar Layers
Authors: Couvidat, S.; García, R. A.; Turck-Chièze, S.; Corbard,
T.; Henney, C. J.; Jiménez-Reyes, S.
2003ApJ...597L..77C Altcode: 2003astro.ph..9806C
From the analysis of low-order GOLF+MDI sectoral modes (l&lt;=3,
6&lt;=n&lt;=15, |m|=l) and LOWL data (l&gt;3), we derive the radial
rotation profile by assuming no latitudinal dependence in the solar
core. These low-order acoustic modes contain the most statistically
significant information about the rotation of the deepest solar layers
and should be least influenced by internal variability associated with
the solar dynamo. After the correction of the sectoral splittings for
their contamination by the rotation of the higher latitudes, we obtain
a flat rotation profile down to 0.2 Rsolar.

---------------------------------------------------------
Title: Analysis of rotational frequency splittings sensitive to the
rotation rate of the solar core
Authors: García, R. A.; Eff-Darwich, A.; Korzennik, S. G.; Couvidat,
S.; Henney, C. J.; Turck-Chièze, S.
2003ESASP.517..271G Altcode: 2003soho...12..271G
Updated solar frequency splitting measurements suggest a slight
decrease of the rotation rate below 0.25 Rsolar and,
albeit preliminary, rule out a core rotating faster than the upper
radiative zone. The estimates of the rotation rate of the deep solar
layers are based on new rotational frequency splittings computed using
data from the GOLF and MDI instruments on board SoHO. Such results,
provided they are confirmed after further analysis, give additional
insight into the dynamics of the solar core.

---------------------------------------------------------
Title: Solar Neutrino Predictions and Variability
Authors: Turck-Chieze, Sylvaine
2003IAUJD...1E..23T Altcode:
More and more precise measurements of solar neutrinos are now available
which have pointed out the presence of oscillations between different
flavours of neutrinos. Nowadays thanks to helioseismology we get
a better description of the solar interior which helps to describe the
region of emission (central core) and the regions where the neutrino
pass through. In this presentation I shall recall how we get now some
predicted values on the neutrino emission in a classical framework. Then
I shall comment on some constraints coming from the central dynamical
effects which become available from recent seismic data. Finally I
shall comment on the possible variability of the solar neutrino data
and discuss the presence or absence of correlations between neutrino
data and some solar signals.

---------------------------------------------------------
Title: The Search for the Solar Core Dynamics with SoHO/GOLF
Authors: Couvidat, S.; Turck-Chieze, S.; Gracia, R. A.; Corbard, T.
2003ASPC..293..276C Altcode: 2003tdse.conf..276C
We present the rotation profile we derive from the GOLF (plus LOWL)
data. This profile shows the onset of a decrease in the rotation
rate of the solar core. If confirmed, it will be useful to constrain
some dynamic effects in the radiative interior and demonstrate the
efficiency of angular momentum transport by gravity waves. We also
present the search for gravity modes on the GOLF data. Detection of
such oscillation modes will be a great breakthrough for the knowledge
of the structure of the core, and the dynamic processes that occur in
the deep layers. The search for both the rotation profile and gravity
modes is strongly related to the dynamics of the core.

---------------------------------------------------------
Title: Challenging Problems in Helio and Asteroseismology
Authors: Turck-Chieze, Sylvaine
2003IAUJD..12E..49T Altcode:
Stellar evolution is improving very quickly thanks to precise
observations and the introduction of hydrodynamical processes. These
phenomena improve our vision of stars in the phases where they have
a dominant role. I shall present some challenging problems choosen
in young clusters high mass stars or final stages of evolution. Helio and asteroseismology will largely contribute to validate
our understanding of the dynamical aspects which are not totally
undercontrolled with present computer performances. The Sun is the
crucial guide for developping tools useful for future space missions. I
shall introduce the difficulties and highlights of this unique case when
we look to the Sun as a star. This experience is extremely rich for
the future asteroseismic observations. Some strategies of observation
will be introduced to disentangle the validation of physical processes
from the waiting asteroseismic observation difficulties.

---------------------------------------------------------
Title: Challenges in Stellar Models: from Helio to Asteroseismology
Authors: Turck-Chieze, Sylvaine
2003IAUJD..12E..50T Altcode:
Stellar evolution modelling is improving very quickly thanks to precise
observations and the introduction of hydrodynamical processes. These
phenomena improve our vision of stars in the phases in which they have
a dominant role. I shall present some challenging problems chosen
in young clusters high-mass stars or final stages of evolution. Helio and asteroseismology will largely contribute to validate our
understanding of the dynamical aspects which are not totally under
control with present computer performances. The Sun is the crucial
guide for developing tools useful for future space missions. I shall
introduce the difficulties and highlights of this unique case when we
look to the Sun as a star. This experience is extremely rich for the
future asteroseismic observations. Some strategies of observation will
be introduced to disentangle the validation of physical processes from
the expected asteroseismic observational difficulties.

---------------------------------------------------------
Title: What Can We Learn from Global Acoustic Modes about the
Structure of the Sun and Centauri A?
Authors: Ballot, J.; Turck-Chièze, S.; García, R. A.; Nghiem,
P. A. P.
2003aahd.conf..497B Altcode:
No abstract at ADS

---------------------------------------------------------
Title: A search for solar g modes in the GOLF data
Authors: Gabriel, A. H.; Baudin, F.; Boumier, P.; García, R. A.;
Turck-Chièze, S.; Appourchaux, T.; Bertello, L.; Berthomieu, G.;
Charra, J.; Gough, D. O.; Pallé, P. L.; Provost, J.; Renaud, C.;
Robillot, J. -M.; Roca Cortés, T.; Thiery, S.; Ulrich, R. K.
2002A&A...390.1119G Altcode:
With over 5 years of GOLF data having some 90% continuity, a new
attempt has been made to search for possible solar g modes. Statistical
methods are used, based on the minimum of assumptions regarding the
solar physics; namely that mode line-widths are small compared with
the inverse of the observing time, and that modes are sought in the
frequency interval 150 to 400 mu Hz. A number of simulations are carried
out in order to understand the expected behaviour of a system consisting
principally of a solar noise continuum overlaid with some weak sharp
resonances. The method adopted is based on the FFT analysis of a time
series with zero-padding by a factor of 5. One prominent resonance at
284.666 mu Hz coincides with a previous tentative assignment as one
member of an n=1, l=1, p-mode multiplet. Components of two multiplets,
previously tentatively identified as possible g-mode candidates from
the GOLF data in 1998, continue to be found, although their statistical
significance is shown to be insufficient, within the present assumption
regarding the nature of the signal. An upper limit to the amplitude
of any g mode present is calculated using two different statistical
approaches, according to either the assumed absence (H0 hypothesis)
or the assumed presence (H1 hypothesis) of a signal. The former yields
a slightly lower limit of around 6 mm/s.

---------------------------------------------------------
Title: Global low frequency acoustic modes after half a solar cycle
aboard SOHO: an improved view of the nuclear core
Authors: Turck-Chièze, S.; Garcí, R. A.; Couvidat, S.; Kosovichev,
A. G.; Bertello, L.; Corbad, T.; Berthomieu, G.; Provost, J.;
Eff-Darwich, A.
2002ESASP.508..593T Altcode: 2002soho...11..593T
Solar global oscillations have now been measured for more than 20
years. The study of these modes has contributed to improve, along
time, the description of the solar core. We have now a proper access
to this part of the Sun, with ground networks observing for more than
10 years and the three instruments aboard SOHO in a quasi continuous
mode for now half a cycle. In this talk, we show the advantages of
the global acoustic modes measured at low frequency. They are due to
their longer lifetime and the reduced influence of the turbulent and
variable surface effects. As a consequence, we have converged last
year, after 30 years of unsuccess, to a boron-8 emitted neutrino flux
in perfect agreement with the better understood detection of these
neutrinos on earth. The splitting at low frequency is also now properly
determined but the extracted rotation information is still limited in
the core. It contains nevertheless the first dynamical vision of this
part of the radiative zone. We will focus on it up to the end of the
SOHO mission, together with the gravity mode region and the possible
internal signature of the magnetic field. Some limits are given on
these observables. Further improvements of their detectability are
under study and will be mentioned.

---------------------------------------------------------
Title: The dynamics of the solar core with SoHO/GOLF
Authors: Couvidat, S.; Turck-Chieze, S.; Garcia, R. A.; Corbard, T.
2002sf2a.conf..441C Altcode:
We will present the latest results of the search for solar gravity modes
and the solar core rotation with the GOLF instrument (aboard SoHO). The
gravity modes are a primary target of the GOLF instrument. They are of
great interest for the knowledge of the solar core and the physical
phenomena that occur inside (pressure and density stratification,
rotation profile, magnetic field, screening effect of the nuclear
reactions...) We will describe the strategy developed at Saclay to
detect them and the results we obtain. We find some candidates and put
some constraints on their amplitude. Such amplitudes are important
to better know the g-mode excitation mechanisms. We will also show
the solar rotation profile for the solar interior (as deep as 0.2 R)
derived with the latest SoHO data. The knowledge of this profile is
needed to put some constraints on the angular momentum distribution and
the related mechanisms. It is also needed to explain the oblateness
of the Sun and have some information about a possible magnetic field
in the core. The rotation rate derived favors a rigidly rotating
radiative zone with a rate close to the one of the outer radiative
zone, although we might have found some hints for a decrease of the
rotation rate near the very center of the Sun.

---------------------------------------------------------
Title: Models of Metal-poor Stars with Gravitational Settling and
Radiative Accelerations. I. Evolution and Abundance Anomalies
Authors: Richard, O.; Michaud, G.; Richer, J.; Turcotte, S.;
Turck-Chièze, S.; VandenBerg, Don A.
2002ApJ...568..979R Altcode:
Evolutionary models have been calculated for Population II stars of
0.5-1.0 Msolar from the pre-main sequence to the lower part
of the giant branch. Rosseland opacities and radiative accelerations
were calculated taking into account the concentration variations of
28 chemical species, including all species contributing to Rosseland
opacities in the OPAL tables. The effects of radiative accelerations,
thermal diffusion, and gravitational settling are included. While
models were calculated for both Z=0.00017 and 0.0017, we concentrate
on models with Z=0.00017 in this paper. These are the first Population
II models calculated taking radiative acceleration into account. It is
shown that, at least in a 0.8 Msolar star, it is a better
approximation not to let Fe diffuse than to calculate its gravitational
settling without including the effects of grad(Fe). In the
absence of any turbulence outside of convection zones, the effects
of atomic diffusion are large mainly for stars more massive than 0.7
Msolar. Overabundances are expected in some stars with
Teff&gt;=6000 K. Most chemical species heavier than CNO are
affected. At 12 Gyr, overabundance factors may reach 10 in some cases
(e.g., for Al or Ni), while others are limited to 3 (e.g., for Fe). The
calculated surface abundances are compared to recent observations of
abundances in globular clusters as well as to observations of Li in
halo stars. It is shown that, as in the case of Population I stars,
additional turbulence appears to be present. Series of models with
different assumptions about the strength of turbulence were then
calculated. One series minimizes the spread on the Li plateau, while
another was chosen with turbulence similar to that present in AmFm
stars of Population I. Even when turbulence is adjusted to minimize
the reduction of Li abundance, there remains a reduction by a factor
of at least 1.6 from the original Li abundance. Independent of the
degree of turbulence in the outer regions, gravitational settling of
He in the central region reduces the lifetime of Population II stars
by 4%-7% depending on the criterion used. The effect on the age of the
oldest clusters is discussed in a forthcoming paper (Paper II). Just
as in Population I stars where only a fraction of stars, such as AmFm
stars, have abundance anomalies, one should look for the possibility of
abundance anomalies of metals in some Population II turnoff stars but
not necessarily in all. Expected abundance anomalies are calculated
for 28 species and compared to observations of M92 as well as to Li
observations in halo field stars.

---------------------------------------------------------
Title: Lithium Depletion in Pre-Main-Sequence Solar-like Stars
Authors: Piau, L.; Turck-Chièze, S.
2002ApJ...566..419P Altcode: 2001astro.ph.11223P
We examine the internal structure of solar-like stars in detail between
0.8 and 1.4 Msolar and during pre-main-sequence phase. Recent
opacity computations of OPAL along with a new hydrodynamical mixing
process have been considered. We also introduce up-to-date nuclear
reaction rates and explore the impact of accretion, mixing length
parameter, nonsolar distributions among metals, and realistic rotation
history. Models predict lithium depletion that we compare to the
7Li content observations of the Sun and four young clusters
of different metallicities and age. We show that we can distinguish two
phases in lithium depletion: (1) a rapid nuclear destruction in the T
Tauri phase before 20 Myr whatever the mass in our range and largely
dependent on the extension and temperature of the convective zone,
and (2) a second phase where the destruction is slow and moderate and
which is largely dependent on the (magneto)hydrodynamic instability
located at the base of the convective zone. Regarding composition
we show the interest that takes on helium and above all the mixture
of heavy elements: carbon, oxygen, silicium, and iron. We outline
the importance of the O/Fe ratio. We note a reasonable agreement on
lithium depletion for the two best-known cases, the Sun and the Hyades,
for solar-like stars. Other clusters suggest that processes which
may partly inhibit the predicted pre-main-sequence depletion cannot
be excluded, in particular for stars below ~0.9 Msolar. We
finally propose different research areas such as initial stellar models
and more realistic atmospheres which could contribute to understanding
better this early phase of evolution and which will be the object of
subsequent works.

---------------------------------------------------------
Title: L-band x-ray absorption of radiatively heated nickel
Authors: Chenais-Popovics, C.; Fajardo, M.; Gilleron, F.; Teubner,
U.; Gauthier, J. -C.; Bauche-Arnoult, C.; Bachelier, A.; Bauche, J.;
Blenski, T.; Thais, F.; Perrot, F.; Benuzzi, A.; Turck-Chièze, S.;
Chièze, J. -P.; Dorchies, F.; Andiel, U.; Foelsner, W.; Eidmann, K.
2001PhRvE..65a6413C Altcode: 2002PhRvE..65a6413C
Absorption of L-M and L-N transitions of nickel has been measured using
point projection spectroscopy. The x-ray radiation from laser-irradiated
gold cavities was used to heat volumetrically nickel foils “tamped
with carbon” up to 20 eV. Experimental spectra have been analyzed
with calculations based on the spin-orbit split arrays statistical
approach and performed for each ionic species Ni5+ to
Ni11+. Using a least-squares fit, this method provides an
ion distribution broader than at local thermodynamic equilibrium, which
is explained by spatial and temporal temperature gradients. A major
improvement in the simulation of the absolute value of transmission
is obtained with a resolved transition array statistical calculation
that reproduces the experimental spectrum with the nominal areal mass
density by taking into account the saturation of narrow lines.

---------------------------------------------------------
Title: Solar Neutrino Emission Deduced from a Seismic Model
Authors: Turck-Chièze, S.; Couvidat, S.; Kosovichev, A. G.; Gabriel,
A. H.; Berthomieu, G.; Brun, A. S.; Christensen-Dalsgaard, J.; García,
R. A.; Gough, D. O.; Provost, J.; Roca-Cortes, T.; Roxburgh, I. W.;
Ulrich, R. K.
2001ApJ...555L..69T Altcode:
Three helioseismic instruments on the Solar and Heliospheric Observatory
have observed the Sun almost continuously since early 1996. This
has led to detailed study of the biases induced by the instruments
that measure intensity or Doppler velocity variation. Photospheric
turbulence hardly influences the tiny signature of conditions in the
energy-generating core in the low-order modes, which are therefore very
informative. We use sound-speed and density profiles inferred from GOLF
and MDI data including these modes, together with recent improvements
to stellar model computations, to build a spherically symmetric
seismically adjusted model in agreement with the observations. The
model is in hydrostatic and thermal balance and produces the present
observed luminosity. In constructing the model, we adopt the best
physics available, although we adjust some fundamental ingredients,
well within the commonly estimated errors, such as the p-p reaction
rate (+1%) and the heavy-element abundance (+3.5%); we also examine the
sensitivity of the density profile to the nuclear reaction rates. Then,
we deduce the corresponding emitted neutrino fluxes and consequently
demonstrate that it is unlikely that the deficit of the neutrino fluxes
measured on Earth can be explained by a spherically symmetric classical
model without neutrino flavor transitions. Finally, we discuss the
limitations of our results and future developments.

---------------------------------------------------------
Title: Low-Degree Low-Order Solar p Modes As Seen By GOLF On
board SOHO
Authors: García, R. A.; Régulo, C.; Turck-Chièze, S.; Bertello,
L.; Kosovichev, A. G.; Brun, A. S.; Couvidat, S.; Henney, C. J.;
Lazrek, M.; Ulrich, R. K.; Varadi, F.
2001SoPh..200..361G Altcode:
Data recovered from the GOLF experiment on board the ESA/NASA SOHO
spacecraft have been used to analyze the low-order low-degree
solar velocity acoustic-mode spectrum below ν=1.5 mHz (i.e.,
1≤n≤9,l≤2). Various techniques (periodogram, RLAvCS,
homomorphic-deconvolution and RLSCSA) have been used and compared to
avoid possible biases due to a given analysis method. In this work,
the acoustic resonance modes sensitive to the solar central region
are studied. Comparing results from the different analysis techniques,
10 modes below 1.5 mHz have been identified.

---------------------------------------------------------
Title: Solar Internal Composition and Nuclear Reaction Rates in the
Light of Helioseismology
Authors: Turck-chièze, S.; Nghiem, P.; Couvidat, S.; Turcotte, S.
2001SoPh..200..323T Altcode:
Acoustic modes are a suitable probe to check the internal solar
composition and give constraints on regions of turbulence or mixing in
stellar interiors. The recent results obtained with the SOHO satellite
involve practically all the acoustic modes and are extremely useful to
check theoretical assumptions. If turbulence is favoured to explain
lithium burning in the tachocline layers located at the base of the
convection zone, central turbulent mixing seems to be strongly rejected
by the present observations. Nuclear reaction rates cannot be directly
verified by this type of probe but they are indirectly constrained
through the behaviour of the sound speed. So, some puzzling problems
concerning Maxwellian distribution or dynamical effects in stellar
plasma are enlightened by the accuracy of the present seismic data.

---------------------------------------------------------
Title: The Seismology of Stars
Authors: Turck-Chièze, Sylvaine
2001sf2a.conf..101T Altcode:
Until recently, the great steps of stellar evolution have been studied
only theoretically. This allowed to account for the observations of
stellar surfaces. However many problems prove that the formalism
is not complete: evolution of young stars, the problem of solar
neutrinos, the burning of lithium, the origin of stellar winds,
ultimate stages of stellar evolution... Often these open problems are
linked to theoric limitations of the framework, which does not account
for internal dynamics. Stellar seismology is a discipline which will
contribute to change this situation while penetrating judiciously in
the stellar interior. Thanks to the ground networks and SOHO satellite,
the heliosismology has already revealed the internal dynamics of the
Sun and has transformed this banal star into a true cosmic physics
laboratory. The quality of the observations is also a formidable
challenge for the theoricians who could validate their assumptions
when the terrestrial laboratory remained impotent. I will show that
confirming the complex physics included in the models is today an
accomplished task, from the center of the Sun until its surface, with
a precision of a few percent. But still more interesting, we begin to
introduce the effects of rotation and of magnetic field, tackling today
the dynamic processes which connect the stellar interior to the eruptive
processes. This opens the gate to a three-dimensional representation
of stars and to a better understanding of galactic enrichment or of
the role of our star in our daily environment. However the Sun cannot,
alone, account for the history of stellar angular momentum or of all
stellar energetic phenomena. It is essential to extend this effort to a
great number of samples, therefore I will show how this is possible and
what we expect from asterosismology projects such as COROT or EDDINGTON.

---------------------------------------------------------
Title: Young solar-type stars evolution: the lithium depletion issue
Authors: Piau, Laurent; Turck-Chièze, S.
2001sf2a.conf..139P Altcode:
Asterosismology and light elements surface abundances allow direct
insight of stellar structure. This talk presents the role of varying
phenomena on the evolution of lithium surface abundance during
solar-like pre-main sequence. Discrepancy between evolutionary models
and young open cluters suggests that the development of the radiative
core during this phase is badly understood. We discuss our results
regarding the impact of microscopic phenomena related to opacities
and therefore to metal fractions or macroscopic phenomena: accretion
and rotation. Then we will address possible impact of protostellar
collapse on present problem.

---------------------------------------------------------
Title: Recent Progress in Solar or Stellar Interior Modelling
Authors: Turck-Chièze, S.
2001IAUS..203...29T Altcode:
Acoustic modes are a suitable probe to check the internal solar
composition and give constraints on regions of turbulence or mixing in
stellar interiors. The satellite SOHO has measured the most significant
acoustic modes including low degree low order modes which are less
dependent on the solar surface effects. Consequently the resulting
accuracy on the sound speed profile from the core to the surface has
been largely improved along the four years of the SOHO mission. The
recent results allow us to check theoretical assumptions of solar
modelling. If turbulence is favoured to explain lithium burning in
the tachocline layers located at the base of the convection zone,
central mixing seems to be definitively rejected by the present
observations. Nuclear reaction rates are also indirectly constrained
through the behaviour of the sound speed. So, some puzzling problems
on maxwellian distribution or dynamical effects in stellar plasma
are enlightened by the accuracy of the present seismic data and the
theoretical neutrino emissions partly checked. We begin to have nowadays
a dynamical vision of the half external part of the Sun, thanks to the
adding density and rotation profile. Gravity modes will be extremely
useful to improve the spatial resolution in the radiative region.

---------------------------------------------------------
Title: g-mode: a new generation of helioseismic instrument
Authors: Turck-Chièze, S.; Robillot, J. M.; Dzitko, H.; Boumier, P.;
Decaudin, M.; Gabriel, A.; Garcia, R. A.; Gree, G.; Pallé, P. L.;
Renaud, C.; Schmitt, D.
2001ESASP.464..331T Altcode: 2001soho...10..331T
The GOLF team pushes a new concept of instrument devoted to the search
of gravity modes and low order low frequency p modes in order to improve
our knowledge of the deep solar interior. The instrumental concept
is to measure the Doppler shift together with the time evolution of
the D1 sodium line using a 15 point resonance spectrometer. A sodium
vapor resonance cell placed in a static magnetic field varying along
the longitudinal axis is used to sample simultaneously 8 points on
each wing of the line. New Active Pixel Sensor detectors will be
specifically designed for this instrument. A low spatial resolution
of the Sun is also under study in this concept. First ground-based
observations with this instrument are scheduled for 2001/2002 at
Tenerife. The space concept of this instrument is under study in France
as an R&amp;T (Research and Technology) study sponsored by CNES, the
French Space Agency. After some determining validation tests, this
kind of instrument might be placed onboard either a micro satellite
or a satellite dedicated to the study of the Sun.

---------------------------------------------------------
Title: Review of solar models and helioseismology
Authors: Turck-Chièze, S.
2001NuPhS..91...73T Altcode:
Acoustic modes are a suitable probe to determine the solar interior
properties and give constraints on regions of turbulence or mixing. The
recent results obtained with the SoHO satellite involve practically
all the acoustic modes and are extremely useful to check theoretical
assumptions. If turbulence is favoured to explain lithium burning
in the tachocline layers located at the base of the convection zone,
central turbulent mixing seems to be strongly rejected by the present
observations. Nuclear reaction rates are indirectly constrained
through the behaviour of the sound speed. So, some puzzling problems
on maxwellian distribution or dynamical effects in stellar plasma are
enlightened by the accuracy of the present seismic data. We begin to
predict neutrino emission fluxes from helioseismology, and propose to
use the difference between these emitted neutrino fluxes and neutrino
fluxes detected on earth to deduce νe properties.

---------------------------------------------------------
Title: Lithium burning in the early stages of stellar evolution
Authors: Piau, L.; Turck-Chièze, S.
2001ESASP.464..435P Altcode: 2001soho...10..435P
Helioseismology has probably pointed out the important role of an
hydrodynamical instability located just below the convective zone in
the destruction of the solar lithium during the main sequence. This
rotationally induced instability occurs in tachocline region where
differential rotation disappears. In order to have a more complete and
quantitative view of the general process of lithium destruction, we
examine in the present study the way the lithium could be burned in the
premainsequence phase for the Sun and young clusters' sunlike-stars. We
discuss here the influence of different physical processes and present
a scenario of the different stages of destruction.

---------------------------------------------------------
Title: Impact of Rotation and Magnetic Fields on Internal Stellar
Composition
Authors: Turck-Chièze, S.
2001coev.conf..145T Altcode:
For decades, the post BBNS history of the elements in different
media has been studied mainly theoretically. Here, we focus on the
helioseismic SOHO satellite results. The precision of the used methods
allows nowadays a direct insight of the solar interior, revealing
the internal composition with a remarkable accuracy. Therefore,
the role of the rotation and magnetic field begins to be studied
and unsolved problems as lithium destruction and neutrino puzzle
progress consequently. This method will be extended to other stars
for progressing on dynamical processes of stellar evolution which
contribute to the enrichment of the interstellar medium.

---------------------------------------------------------
Title: Lithium Burning in the Early Evolution of the Sun and
Sun-like Stars
Authors: Piau, L.; Turck-Chièze, S.
2001ASPC..243..639P Altcode: 2001fdtl.conf..639P
No abstract at ADS

---------------------------------------------------------
Title: The search for solar low frequency resonant modes
Authors: Bertello, L.; García, R. A.; Varadi, F.; Turck-Chièze,
S.; Ulrich, R. K.; Henney, C. J.; Couvidat, S.
2001ESASP.464..479B Altcode: 2001soho...10..479B
We present the results obtained from the analysis of 4-year long GOLF
and MDI time series. The GOLF time series includes the period where the
instrument operated in the blue wing of the doublet Na D lines, and also
the data from the current red-wing photometric mode. Disk-averaged MDI
velocity signals from the calibrated level-1.4 MDI LOI-proxy Doppler
images were obtained using integrated spatially weighted masks. The
analysis was carried out by Random-Lag Singular Cross-Spectrum
Analysis. This technique searches for simultaneous oscillatory
components in two or more time series, and has been proven to be very
effective for the identification of solar acoustic modes of low angular
degree and low radial order. In the present work we have extended our
analysis to the frequency range between 200 and 1500 microHZ, which
includes the region of low radial order gravity modes. Selected cases
are presented and compared with the results obtained using classical
spectral estimations based on Fourier transforms.

---------------------------------------------------------
Title: The physics of the solar core deduced from GOLF and MDI
acoustic modes
Authors: Turck-Chièze, S.; Kosovichev, A. G.; Couvidat, S.; García,
R. A.; Nghiem, P.; Pérez Hernández, F.; Turcotte, S.
2001ESASP.464..485T Altcode: 2001soho...10..485T
We use the recent results on solar acoustic modes coming from GOLF
and MDI, to demonstrate that we improve the quality of the inversion
of the sound speed and the density by avoiding several biases coming
from the turbulent surface. The present accuracy allows a quantitative
discussion on the physics of the solar nuclear core. We now exclude
several phenomena which are incompatible with the present observations:
central turbulent mixing or large modification of the pp chain nuclear
reaction rates. We propose a solution to the difference between the
Sun and solar models only in terms of turbulence at the base of the
convective zone, an increase of the weak interaction p-p reaction
rate by 2% in the framework of intermediate Mitler screening, and
an underestimate of CNO composition of no more than 3%. Even if this
solution is probably not unique, it allows a prediction of neutrino
fluxes induced by helioseismology. We also note that nowadays,
helioseismology puts just a few constraints on the reaction rates of
the CNO cycle, and let place for lower high energy neutrino predictions.

---------------------------------------------------------
Title: Analysis of low frequency signal with the GOLF experiment:
methodology and results
Authors: García, R. A.; Bertello, L.; Turck-Chièze, S.; Couvidat,
S.; Gabriel, A. H.; Henney, C. J.; Régulo, C.; Robillot, J. M.;
Roca Cortés, T.; Ulrich, R. K.; Varadi, F.
2001ESASP.464..473G Altcode: 2001soho...10..473G
Four years of GOLF velocity time series have been used to study the
low frequency part of the solar spectrum below 1.5 mHz. This paper
discusses the methods already developed for the research of the
low-degree low-order acoustic modes by Garcia et al. (2000) and for
the gravity modes by Turck-Chieze et al. (2000). These methods are
based on our knowledge of the general theoretical properties of the p
and g modes that lead us to determine the statistical significance of
the structures (multiplets) present in the GOLF spectrum in terms of
p- and g-mode candidates. In addition to the search of single peaks,
we try to detect multiplets (l = 1, 2 and 3) which allows us to lower
the detection threshold while keeping the same confidence level. We
will concentrate the discussion on the limits of this search that only
takes into account those peaks above a selected statistical threshold
giving an estimation of the possible uncertainties due to the solar
noise and the nature of the solar resonances.

---------------------------------------------------------
Title: Sensitivity of the GOLF signal to combined solar velocity
and intensity variations
Authors: Ulrich, R. K.; García, R. A.; Robillot, J. -M.;
Turck-Chièze, S.; Bertello, L.; Charra, J.; Dzitko, H.; Gabriel,
A. H.; Roca Cortés, T.
2000A&A...364..799U Altcode:
The GOLF instrument provides a stable and continuous measurement of
the intensity of spatially integrated sunlight in one wing of the
sodium D lines. Because the detected radiation results from atomic
scattering, the GOLF signal can be traced to an atomic reference
wavelength. The planned operations were to involve a form of relative
photometry through the use of measurements on both the blue and red
wings of the solar D lines of neutral sodium. However, due to the
occasional malfunction of the polarization subsystem a “one wing
photometric mode" operational alternative has been selected in order
to ensure achievement of a 100% duty cycle. In this case, the signal
observed consists of two photometric measurements at only one wing
of each line of the sodium doublet separated by gx0.43 picometers
(pm). The sodium cell system in GOLF combines photons scattered at
three different wavelengths: one at D_1 and two at D_2. This paper
developes a formalism to describe this system in terms of the solar
spectral line profiles. A method of converting the one wing data to an
effective velocity scale is presented. The method is applied to the
nearly continuous 804 day sequence received from the GOLF instrument
prior to the loss of telecommunications with SOHO on 24-June-1998. The
resulting time sequence is part of the GOLF archive and can be made
available to investigators. This publication describes some properties
of this time series.

---------------------------------------------------------
Title: Solar Interior: Standard Models
Authors: Turck-Chièze, S.
2000eaa..bookE2020T Altcode:
Due to its proximity, there are many properties of the Sun which we can
observe. Consequently, it plays a key role in our understanding of the
physics of the internal structure of stars. Standard models of the Sun
are theoretical representations of its present structure. These models
include the best physical description of the fundamental processes
which contribute to solar evolution and allow t...

---------------------------------------------------------
Title: Identification of Solar Acoustic Modes of Low Angular Degree
and Low Radial Order
Authors: Bertello, L.; Varadi, F.; Ulrich, R. K.; Henney, C. J.;
Kosovichev, A. G.; García, R. A.; Turck-Chièze, S.
2000ApJ...537L.143B Altcode:
We present evidence for the detection of low radial order (n&lt;10)
acoustic modes of low angular degree, l=0-2, in the 759 day long
Global Oscillations at Low Frequency and Michelson Doppler Imager time
series. We used Random-Lag Singular Cross-Spectrum Analysis, which
searches for simultaneous oscillatory components in two or more time
series. We have determined 11 modes in the range n=3-9, of which eight
modes confirm the previous measurements by Toutain et al. and three
modes of l=0 and n=3, 5, and 6 are reliably measured for the first
time. The errors of frequency determination are also significantly
reduced for several previously identified modes. New sound speed
inversion results suggest that the effect of inhomogeneous initial
composition of the Sun should be included in the standard solar model.

---------------------------------------------------------
Title: Erratum: Standard Solar Models in the Light of New Helioseismic
Constraints. II. Mixing below the Convective Zone
Authors: Brun, A. S.; Turck-Chièze, S.; Zahn, J. P.
2000ApJ...536.1005B Altcode:
In the paper “Standard Solar Models in the Light of New
Helioseismic Constraints. II. Mixing below the Convective Zone”
by A. S. Brun, S. Turck-Chièze, and J. P. Zahn (525, 1032 [1999]),
several corrections are required: 1. The words “greater than”
just after equation (11) for the definition of rbcz
should be removed. 2. The beginning of first sentence of the next
paragraph should read: “With the latitudinal dependence of the angular
velocity at the base of the convection zone borrowed from Thompson et
al. (1996), Ωbcz/2π=456-72x2-42x4
nHz,” instead of “Ωbcz&gt;/2π=456-72x2-
42x4.” 3. In the footnote to Table 1, “Rbzc”
should be “Rbcz,” as it is appears for “Tbcz”
in the same footnote. 4. In Table 2, in the “Parameters” column,
“i0” should be “Z0,” as in Table 1. 5. In
Table 3, “Observaton” should be “Observation.” The Press sincerely
regrets these errors.

---------------------------------------------------------
Title: Comparison of Frequencies and Rotational Splittings of Solar
Acoustic Modes of Low Angular Degree from Simultaneous MDI and
GOLF Observations
Authors: Bertello, L.; Henney, C. J.; Ulrich, R. K.; Varadi, F.;
Kosovichev, A. G.; Scherrer, P. H.; Roca Cortés, T.; Thiery, S.;
Boumier, P.; Gabriel, A. H.; Turck-Chièze, S.
2000ApJ...535.1066B Altcode:
During the years 1996 through 1998 the Michelson Doppler Imager (MDI)
and the Global Oscillations at Low Frequency (GOLF) experiments on the
Solar and Heliospheric Observatory (SOHO) mission have provided unique
and nearly uninterrupted sequences of helioseismic observations. This
paper describes the analysis carried out on power spectra from 759
days of calibrated disk-averaged velocity signals provided by these two
experiments. The period investigated in this work is from 1996 May 25
to 1998 June 22. We report the results of frequency determination of
low-degree (l&lt;=3) acoustic modes in the frequency range between 1.4
mHz and 3.7 mHz. Rotational splittings are also measured for nonradial
modes up to 3.0 mHz. The power spectrum estimation of the signals
is performed using classical Fourier analysis and the line-profile
parameters of the modes are determined by means of a maximum likelihood
method. All parameters have been estimated using both symmetrical and
asymmetrical line profile-fitting formula. The line asymmetry parameter
of all modes with frequency higher than 2.0 mHz is systematically
negative and independent of l. This result is consistent with the
fact that both MDI and GOLF data sets investigated in this paper are
predominantly velocity signals, in agreement with previous results. A
comparison of the results between the symmetric and asymmetric fits
shows that there is a systematic shift in the frequencies for modes
above 2.0 mHz. Below this frequency, the line width of the modes
is very small and the time base of the data does not provide enough
statistics to reveal an asymmetry. In general, the results show that
frequency and rotational splitting values obtained from both the
MDI and GOLF signals are in excellent agreement, and no significant
differences exist between the two data sets within the accuracy of the
measurements. Our results are consistent with a uniform rotation of
the solar core at the rate of about 435 nHz and show only very small
deviations of the core structure from the standard solar model.

---------------------------------------------------------
Title: Structure of the Solar Core: Effect of Asymmetry of Peak
Profiles
Authors: Basu, S.; Turck-Chièze, S.; Berthomieu, G.; Brun, A. S.;
Corbard, T.; Gonczi, G.; Christensen-Dalsgaard, J.; Provost, J.;
Thiery, S.; Gabriel, A. H.; Boumier, P.
2000ApJ...535.1078B Altcode: 2000astro.ph..1208B
Recent studies have established that peaks in solar oscillation
power spectra are not Lorentzian in shape but have a distinct
asymmetry. Fitting a symmetric Lorentzian profile to the peaks,
therefore, produces a shift in frequency of the modes. Accurate
determination of low-frequency modes is essential to infer the structure
of the solar core by inversion of the mode frequencies. In this paper
we investigate how the changes in frequencies of low-degree modes
obtained by fitting symmetric and asymmetric peak profiles change the
inferred properties of the solar core. We use data obtained by the
Global Oscillations at Low Frequencies (GOLF) project on board the
SOHO spacecraft. Two different solar models and inversion procedures
are used to invert the data in order to determine the sound speed in
the solar core. We find that for a given set of modes no significant
difference in the inferred sound speed results from taking asymmetry
into account when fitting the low-degree modes.

---------------------------------------------------------
Title: Solar modelling: Theory and Verification
Authors: Turck-Chièze, S.; Brun, A. S.; Garcia, R. A.
2000NuPhS..87..162T Altcode:
After 30 years of investigation, the solar neutrino problem is still
puzzling but the perspectives are extremely encouraging, due to the
large improvements obtained on the experimental side including nuclear
reaction rates, high statistics in neutrino detections, precise acoustic
mode properties and hope to detect gravity modes. The present status,
including the differences between neutrino predictions and neutrino
flux detections, confirms the general features of solar modelling
proposed in the sixties but reveals a rich field of Astrophysics and
Particle Physics. The helioseismic investigation of the solar interior
with the satellite SOHO begins to offer a complete verification of the
solar structure, the introduction of dynamical effects will modify the
neutrino emissions and the solar properties on rotation and magnetic
field could appear important for the solution of the puzzle if the
properties of the neutrinos (mass and magnetic moment) are revealed
more complex than thought at the beginning

---------------------------------------------------------
Title: The Solar Neutrino Puzzle
Authors: Turck-Chièze, S.
2000NuPhS..80..183T Altcode:
Neutrino fluxes coming from the Sun are now measured on earth with
improved accuracy. The predicted neutrino emissions in the solar core
depend on fundamental nuclear and astrophysical properties which are
nowadays better constrained by experiments. This paper is focused on
the ighlights in these fields and on their perspectives

---------------------------------------------------------
Title: Analysis of asymmetric p-mode profiles in GOLF data
Authors: Thiery, S.; Boumier, P.; Gabriel, A. H.; Bertello, L.;
Lazrek, M.; García, R. A.; Grec, G.; Robillot, J. M.; Roca Cortés,
T.; Turck-Chièze, S.; Ulrich, R. K.
2000A&A...355..743T Altcode:
We show here evidence for the necessity of an asymmetric form in
modelling the profile of an acoustic mode in the power spectral
density. The analysis was performed on a 805-day series of GOLF data
(l=0 to 3). The assumptions used for the fits are discussed and their
consequences quantified, in particular for the optimum choice of the
fitting spectral window. Values are given for the bias on the mode
parameters (frequency, width, splitting) when using a Lorentzian
fit. The bias depends on the degree l and on the frequency, and when
taken into account leads to variations in the mode parameters with
degree more consistent with theoretical expectations.

---------------------------------------------------------
Title: The tachocline and lithium history in solar-like stars
Authors: Piau, L.; Turck-Chièze, S.; Brun, A. S.
2000ASPC..198..303P Altcode: 2000scac.conf..303P
No abstract at ADS

---------------------------------------------------------
Title: Standard Solar Models in the Light of New Helioseismic
Constraints. II. Mixing below the Convective Zone
Authors: Brun, A. S.; Turck-Chièze, S.; Zahn, J. P.
1999ApJ...525.1032B Altcode: 1999astro.ph..6382B
In previous work, we have shown that recent updated standard solar
models cannot reproduce the radial profile of the sound speed at
the base of the convective zone and fail to predict the photospheric
lithium abundance. In parallel, helioseismology has shown that the
transition from differential rotation in the convective zone to almost
uniform rotation in the radiative solar interior occurs in a shallow
layer called the tachocline. This layer is presumably the seat of a
large-scale circulation and of turbulent motions. Here we introduce a
macroscopic transport term in the structure equations that is based on
a hydrodynamical description of the tachocline proposed by Spiegel &amp;
Zahn, and we calculate the mixing induced within this layer. We discuss
the influence of different parameters that represent the tachocline
thickness, the Brunt-Väisälä frequency at the base of the convective
zone, and the time dependence of this mixing process along the Sun's
evolution. We show that the introduction of such a process inhibits
the microscopic diffusion by about 25%. Starting from models including
a pre-main-sequence evolution, we obtain (1) a good agreement with
observed photospheric chemical abundance of light elements such as
3He, 4He, 7Li, and 9Be;
(2) a smooth composition gradient at the base of the convective zone;
and (3) a significant improvement of the sound-speed square difference
between the seismic Sun and the models in this transition region when
we allow the photospheric heavy-element abundance to adjust, within
the observational incertitude, as a result of the action of this mixing
process. The impact on neutrino predictions is also discussed.

---------------------------------------------------------
Title: Power spectra comparison between GOLF and MDI velocity
observations
Authors: Henney, C. J.; Ulrich, R. K.; Bertello, L.; Bogart,
R. S.; Bush, R. I.; Scherrer, P. H.; Palle, P. L.; Roca Cortes, T.;
Turck-Chieze, S.
1999AAS...194.5617H Altcode: 1999BAAS...31..914H
We present a comparison of the velocity power spectra between the GOLF
and MDI instruments. In addition, this poster outlines work towards
creating a GOLF-simulated signal utilizing MDI velocity images. The
simulation of the GOLF signal is achieved by integrating spatially
weighted masks with MDI LOI-proxy velocity images. The GOLF-simulated
signal and a selection of additional spatially masked MDI velocity
signals are compared with the observed GOLF signal for a 759 day period
from May 25, 1996 through June 22, 1998. Ultimately, a cross-analysis
process between GOLF and MDI signals could lead to an enhancement
of our ability to detect low frequency solar oscillations. The
signal-to-background ratio (S/B) for the GOLF and the spatially masked
MDI velocity data is presented for low degree (l &lt;= 3) and low
frequency p-modes. We find that signals from both MDI and GOLF are
beneficial for detecting low degree (l &lt;= 3) and low frequency
(&lt; 2000 mu Hz) p-modes. For the frequency range and the signals
compared in this poster, the GOLF signal has the highest S/B for l=0
p-modes. The S/B of the GOLF and MDI central region masked signals
is good for detecting l=1 p-modes. For l &gt;= 2 p-modes, the central
region masked signals have the highest S/B of the power spectra compared
here. In addition, the S/B of the preliminary GOLF-simulated signal
is found to be more similar to the GOLF signal than the MDI LOI-proxy
signal without spatial masking for the modes investigated here.

---------------------------------------------------------
Title: Power spectra comparison between GOLF and spatially masked
MDI velocity signals
Authors: Henney, C. J.; Ulrich, R. K.; Bertello, L.; Bogart, R. S.;
Bush, R. I.; Scherrer, P. H.; Roca Cortés, T.; Turck-Chièze, S.
1999A&A...348..627H Altcode:
The Global Oscillations at Low Frequency (GOLF) and the Michelson
Doppler Imager (MDI) instruments aboard the Solar and Heliospheric
Observatory (SOHO) give an excellent opportunity to search for solar
low frequency oscillation modes previously undetected from ground
based experiments. Presented here is a comparison of the velocity power
spectra between the two instruments. In addition, this paper outlines
work towards creating a GOLF-simulated signal utilizing MDI velocity
images. The simulation of the GOLF signal is achieved by integrating
spatially weighted masks with MDI full-disk Doppler images. The
GOLF-simulated signal and a selection of additional spatially masked
MDI velocity signals are compared with the observed GOLF signal for a
759 day period from May 25, 1996 through June 22, 1998. Ultimately,
a cross-analysis process between GOLF and MDI signals could lead
to an enhancement of our ability to detect low frequency solar
oscillations. For low degree (l&lt;= 3) and low frequency acoustic
modes, the signal-to-background ratio between GOLF and the spatially
masked MDI velocity data is compared here.

---------------------------------------------------------
Title: The solar neutrino puzzle: the way ahead
Authors: Turck-Chièze, S.
1999NewA....4..325T Altcode:
After a rapid review of the different activities which have contributed
to the understanding of solar neutrino detections, we examine the
present situation, the open questions and propose new directions
of improvements.

---------------------------------------------------------
Title: The integrated magnetic field of the Sun as seen by GOLF on
board SOHO
Authors: García, R. A.; Boumier, P.; Charra, J.; Foglizzo, T.;
Gabriel, A. H.; Grec, G.; Régulo, C.; Robillot, J. M.; Turck-Chièze,
S.; Ulrich, R. K.
1999A&A...346..626G Altcode:
An objective of the GOLF experiment (Global Oscillations at Low
Frequencies) on-board the SOHO (Solar and Heliospheric Observatory)
space mission was to measure the line-of-sight component of the
disk-averaged magnetic field of the Sun. In this paper, a theoretical
study of this observable is presented. The newly developed techniques
are tested using simulated data series based on the observation of this
experiment, and the sensitivity of GOLF to magnetic measurements is
calculated. An average solar mean magnetic field of 0.120 +/- 0.002
G has been found corresponding to the minimum of solar activity by
analyzing 26 days of full GOLF data. The power spectrum of this field
is calculated and the main characteristics {are} described.

---------------------------------------------------------
Title: Solar oscillations: time analysis of the GOLF p-mode signal
Authors: Renaud, C.; Grec, G.; Boumier, P.; Gabriel, A. H.; Robillot,
J. M.; Roca Cortés, T.; Turck-Chièze, S.; Ulrich, R. K.
1999A&A...345.1019R Altcode:
We determine the intrinsic phase lag of the GOLF data for the solar
p-mode velocity deduced either from one of the narrow band photometers
working alternatively on blue and red wing of the sodium lines. The
timing of the “blue wing” velocity coming from the current GOLF data
is given in respect to the ground-based observations. The phase lag for
the “blue” velocity is 6 s in advance relatively to a velocity coming
from a differential device. For individual p modes, the phase lag from
the “blue” velocity to the “red” velocity are not in opposition of
phase, as expected in a very simple solar model, but differs from 8(o)
to 18(o) from the opposition, depending on the degree and the radial
order of the acoustic mode. The measurement of the differential lag
between the blue and red wings of the D lines may open a new way to
monitor the temperature oscillations with the optical depth.

---------------------------------------------------------
Title: Results from the GOLF instrument on SOHO
Authors: Gabriel, A. H.; Turck-Chièze, S.; García, R. A.; Pallé,
P. L.; Boumier, P.; Thiery, S.; Baudin, F.; Grec, G.; Ulrich, R. K.;
Bertello, L.; Roca Cortés, T.; Robillot, J. -M.
1999AdSpR..24..147G Altcode:
An 800 day series of GOLF velocity data, with uniquely high continuity
and stability, offers the best ever signal to noise ratio obtained
in global Sun observations. Following meticulous efforts to provide
reliable calibration, these data have been used for measurements of
frequencies, line-widths and power in the p-modes, which are used
for inversion to give the internal sound speed, for comparison with
theoretical models. A search for g-modes is at present inconclusive, but
has yielded two possible candidate frequencies. The analysis available
today is regarded as preliminary and more complete methods are currently
in hand. With the resumption of routine observations following the
SOHO recovery, it is hoped that the data can be considerably extended,
enabling changes with the solar cycle to be explored, as well as an
extended g-mode search.

---------------------------------------------------------
Title: On the nature of the current GOLF p-mode signal
Authors: Pallé, P. L.; Régulo, C.; Roca Cortés, T.; García, R. A.;
Jiménez, A.; Boumier, P.; Gabriel, A.; Grec, G.; Robillot, J. M.;
Turck-Chièze, S.; Ulrich, R. K.; SOI Team
1999A&A...341..625P Altcode:
The GOLF experiment on board SOHO is designed to measure global
oscillations of the disk-integrated sunlight with high sensitivity and
with long term stability. The GOLF data is thus ideally suited for
both the study of the p-mode spectrum and to address the search for
gravity modes. Due to their occasional malfunction the project decided
to stop the rotating polarizing elements at an optimum place in order to
maintain a precise sequence of measurements with the highest possible
duty cycle. This action means that subsequently GOLF only measures two
monochromatic intensities {I}_b(+) and {I}_b(-) on the blue wing of
the sodium doublet. In this work we investigate the nature of these
signals separately and in combinations. Our method is to study the
temporal relative phase relations between the low degree (l &lt;=
3) p-mode signals derived from data sets obtained from simultaneous
observations, both from other SOHO instruments (GOLF and SOI) and from
Mark- I, the Tenerife station of the ground-based BiSON network. It
is found that these signals are “almost” pure velocity signals. A
simple model indicates that a contamination of a pure intensity-like
signal of 14% amplitude would fully explain the true nature of the
current GOLF signal. Moreover, it is found that the ratios, defined
for other instruments (Mark-I, SOI and, by extension BiSON and IRIS),
also have exactly the same nature as the GOLF ratio.

---------------------------------------------------------
Title: The Helioseismic Constraints on 7Li and
9Be from SOHO
Authors: Brun, A. S.; Turck-Chièze, S.
1999ASPC..171...64B Altcode: 1999lcrr.conf...64B
No abstract at ADS

---------------------------------------------------------
Title: Mixing Below the Solar Convective Zone
Authors: Brun, A. S.; Turck-Chièze, S.; Zahn, J. -P.
1999ASPC..173..293B Altcode: 1999sstt.conf..293B
No abstract at ADS

---------------------------------------------------------
Title: Power spectra comparison between GOLF and MDI velocity
observations.
Authors: Henney, C. J.; Ulrich, R. K.; Bertello, L.; Bogart, R. S.;
Bush, R. I.; Scherrer, P. H.; Pallé, P. L.; Roca Cortés, T.;
Turck-Chièze, S.
1999BAAS...31Q1237H Altcode:
No abstract at ADS

---------------------------------------------------------
Title: The Solar Neutrino Puzzle
Authors: Turck-Chieze, S.
1998tx19.confE.375T Altcode:
After a rapid review of the different activities which have contributed
to the understanding of solar neutrino detections, I shall present
very precise helioseismic results which constrain the solar structure
and begin to reveal the solar core. Sound speed, density and rotation
profiles are new interesting tools to explore the central region in
order to go beyond the standard solar model. Therefore helioseismology
allows a better estimate of the emitted neutrino fluxes and of their
related accuracy. Then I shall mention the open questions and propose
new directions of improvements.

---------------------------------------------------------
Title: Standard Solar Models in the Light of New Helioseismic
Constraints. I. The Solar Core
Authors: Brun, A. S.; Turck-Chièze, S.; Morel, P.
1998ApJ...506..913B Altcode: 1998astro.ph..6272B
In this paper, we examine a new, updated solar model that takes
advantage of the recent reexamination of nuclear reaction rates and
the microscopic diffusion of helium and heavy elements. Our best model
fits the helioseismic data reasonably well, giving the base of the
convective zone at Rbcz = 0.715, the photospheric helium in
mass fraction as 0.243, and the sound-speed square difference between
the Sun and the model as δc2/c2 &lt; 1%. This
model leads to a reestimate of neutrino fluxes, giving 7.18 SNU for
the chlorine experiment, 127.2 SNU for the gallium detector, and 4.82
106 cm-2 s-1 for the 8B
neutrino flux. Acoustic-mode predictions are also estimated. We then
consider the radiative zone and discuss what we learn from such a
model when confronted with the present helioseismic constraints from
space experiments aboard SOHO. We present three models that respect
these constraints and better fit the seismic observations by taking
advantage of the known physical uncertainties--nuclear reaction rates,
CNO abundances, and microscopic diffusion. We also study some current
questions, such as the possibility of mixing in the nuclear core, the
revision of the solar radius, and the influence of the solar age. We
conclude that the standard model, inside its inherent uncertainties, is
robust in light of the present acoustic-mode detection and that mixing
in the core is not really favored, even though a proper understanding of
the angular momentum evolution with time has not yet been reached. The
initial solar helium abundance seems more and more constrained;
this study supports an initial abundance between 0.273 and 0.277 in
mass fraction. This analysis allows us to define minimal values for
neutrino predictions, compatible with present seismic results. We
note that a reduction of about 30% in chlorine and water detectors,
which is more than half the discrepancy with the experimental results,
is still supported by the present study. This work also emphasizes the
fact that acoustic-mode determination does not put strong constraints
on the nuclear plasma characteristics. Finally, we estimate g-mode
frequencies in a range that may be accessible to the satellite SOHO;
these results emphasize the substantially improved sensitivity of these
modes to details of the nuclear solar core, and show the frequency
dependence of these modes for the different models previously discussed.

---------------------------------------------------------
Title: Solar fusion cross sections
Authors: Adelberger, Eric G.; Austin, Sam M.; Bahcall, John N.;
Balantekin, A. B.; Bogaert, Gilles; Brown, Lowell S.; Buchmann, Lothar;
Cecil, F. Edward; Champagne, Arthur E.; de Braeckeleer, Ludwig; Duba,
Charles A.; Elliott, Steven R.; Freedman, Stuart J.; Gai, Moshe;
Goldring, G.; Gould, Christopher R.; Gruzinov, Andrei; Haxton,
Wick C.; Heeger, Karsten M.; Henley, Ernest; Johnson, Calvin W.;
Kamionkowski, Marc; Kavanagh, Ralph W.; Koonin, Steven E.; Kubodera,
Kuniharu; Langanke, Karlheinz; Motobayashi, Tohru; Pandharipande,
Vijay; Parker, Peter; Robertson, R. G.; Rolfs, Claus; Sawyer, R. F.;
Shaviv, N.; Shoppa, T. D.; Snover, K. A.; Swanson, Erik; Tribble,
Robert E.; Turck-Chièze, Sylvaine; Wilkerson, John F.
1998RvMP...70.1265A Altcode: 1998astro.ph..5121A
We review and analyze the available information on the nuclear-fusion
cross sections that are most important for solar energy generation and
solar neutrino production. We provide best values for the low-energy
cross-section factors and, wherever possible, estimates of the
uncertainties. We also describe the most important experiments and
calculations that are required in order to improve our knowledge of
solar fusion rates.

---------------------------------------------------------
Title: Time-correlation of the solar p-mode velocity signal from GOLF
Authors: Gabriel, M.; Grec, G.; Renaud, C.; Gabriel, A. H.; Robillot,
J. M.; Roca Cortes, T.; Turck-Chieze, S.; Ulrich, R. K.
1998A&A...338.1109G Altcode:
Since the launch of SOHO, the Solar Heliospheric Orbital Observatory,
the helioseismic observations are nearly uninterrupted. The GOLF
instrument (A. Gabriel et al., 1997) measures the mean velocity
integrated over the disk. The autocorrelation function of this velocity
shows two main features: Firstly, the initial decrease of the peak
amplitudes is much faster than expected from the width of the most
powerful lines and %!second secondly it does not %!go decrease to
zero for large times. These two features have been studied using the
model of stochastically excited oscillators.The second one can also be
understood on the basis of a completely general discussion. We show
that the fast initial decrease of the peak amplitudes results from
the departure of the mode frequencies from the values predicted by
the first order asymptotic theory (the modes are not equidistant) and
that the damping time of the modes has only a small influence. The non
vanishing amplitudes at large times result either from the presence of a
periodic non-stochastic component in the signal or from the stochastic
nature of the excitation. Further tests have shown that the second
possibility is the right one. This result gives a new argument in
favor of the stochastic excitation of solar p-modes. The use of the
ACF also suggests a new method to study line profiles which has been
tested for radial modes and Lorentz profiles.

---------------------------------------------------------
Title: High-Frequency Peaks in the Power Spectrum of Solar Velocity
Observations from the GOLF Experiment
Authors: García, R. A.; Pallé, P. L.; Turck-Chièze, S.; Osaki,
Y.; Shibahashi, H.; Jefferies, S. M.; Boumier, P.; Gabriel, A. H.;
Grec, G.; Robillot, J. M.; Roca Cortés, T.; Ulrich, R. K.
1998ApJ...504L..51G Altcode:
The power spectrum of more than 630 days of full-disk solar velocity
data, provided by the GOLF spectrophotometer aboard the Solar and
Heliospheric Observatory, has revealed the presence of modelike
structure well beyond the acoustic cutoff frequency for the solar
atmosphere (νac~5.4 mHz). Similar data produced by
full-disk instruments deployed in Earth-based networks (BiSON and
IRIS) had not shown any peak structure above νac: this
is probably due to the higher levels of noise that are inherent in
Earth-based experiments. We show that the observed peak structure
(νac&lt;=ν&lt;=7.5 mHz) can be explained by a simple
two-wave interference model if the high-frequency waves are partially
reflected at the back side of the Sun.

---------------------------------------------------------
Title: Composition and Opacity in the Solar Interior
Authors: Turck-Chieze, Sylvaine
1998SSRv...85..125T Altcode:
Detailed abundances of elements from hydrogen up to iron are necessary
to perform a precise model of the solar structure. Most of them have
been deduced from photospheric observed values, some others from the
meteoritic composition. Nowadays, thanks to helioseismic constraints,
they seem more and more under control.

---------------------------------------------------------
Title: Are solar acoustic modes correlated?
Authors: Foglizzo, T.; Garcia, R. A.; Boumier, P.; Charra, J.; Gabriel,
A. H.; Grec, G.; Robillot, J. M.; Roca Cortes, T.; Turck-Chieze, S.;
Ulrich, R. K.
1998A&A...330..341F Altcode: 1997astro.ph..9095F
We have studied the statistical properties of the energy of individual
acoustic modes, extracted from 310 days of GOLF data near the solar
minimum. The exponential distribution of the energy of each mode is
clearly seen. The modes are found to be uncorrelated with a partial
0.6% accuracy, thus supporting the hypothesis of stochastic excitation
by the solar convection. Nevertheless, the same analysis performed on
the same modes just before the solar maximum, using IPHIR data, rejects
the hypothesis of no correlation at a 99.3% confidence level. A simple
model suggests that 31.3partialm 9.4% of the energy of each mode is
coherent among the modes studied in IPHIR data, correponding to a mean
correlation of 10.7partialm 5.9%.

---------------------------------------------------------
Title: Sensitivity of the Sound Speed to the Physical Processes
Included in the Standard Solar Model
Authors: Turck-Chièze, S.; Basu, S.; Berthomieu, G.; Bonanno, A.;
Brun, A. S.; Christensen-Dalsgaard, J.; Gabriel, M.; Morel, P.;
Provost, J.; Turcotte, S.; GOLF Team
1998ESASP.418..555T Altcode: 1998soho....6..555T
The accuracy of the present seismic data allows us to check the
solar internal sound speed down to the core. This is a great support
to check the hypothesis of the classical stellar evolution and to
predict the neutrino fluxes. The interpretation of these measurements
supposes an accurate determination of the structure of the standard
solar model as a first step. It is why a continuing effort has been
devoted to the knowledge of the physical quantities included in this
framework. In this poster we present 6 different solar models calculated
by different groups of the GOLF consortium. These models include the
most recent progress in atomic physics and nuclear physics. Then, we
discuss the sensitivity of the sound speed difference, between GOLF+MDI
observations and models, to different ingredients, in peculiar to the
opacity coefficients and the determination of the solar age.

---------------------------------------------------------
Title: Stability Study of the GOLF Blue Wing Working Cycle
Authors: Robillot, J. M.; Turck-Chieze, S.; Garcia, R. A.; Boumier,
P.; Charra, J.; Ulrich, R. K.; Gabriel, A.; Grec, G.; Roca Cortes, T.
1998ESASP.418..317R Altcode: 1998soho....6..317R
The GOLF experiment is a resonant scattering spectrophotometer in
flight on board the SOHO mission, originally designed to measure the
intensity of the solar radiation at 4 selected positions within the
sodium doublet (D1 at λ 5896 and D2 at λ 5890 AA). Each position was
determined by a modulated magnetic field and a combination of rotating
polarizers (see Gabriel et al. 1995, 1997 for a full description of the
instrument). Due to occasional malfunctions of the polarizing element
that allows to switch between the two wings of the solar profile,
it was decided to stop the mechanism in a safety position. Thus,
only two monochromatic intensities, Ib+ and
Ib- are measured but a duty cycle close to 100 %
is achieved. After more than two years of blue wing measurements we
show the long term stability of the GOLF experiment and we discuss
their impact on the new derived velocity.

---------------------------------------------------------
Title: Report from Working Group Session 3: Solar Structure: Models
and Inversions
Authors: Turck-Chièze, S.; Basu, S.
1998ESASP.418..573T Altcode: 1998soho....6..573T
No abstract at ADS

---------------------------------------------------------
Title: Macroscopic Processes in the Solar Interior
Authors: Brun, A. S.; Turck-Chièze, S.; Zahn, J. P.
1998ESASP.418..439B Altcode: 1998astro.ph..7090B; 1998soho....6..439B
With the recent results of heliseismology aboard SOHO, the solar models
are more and more constrained (Brun, Turck-Chièze et Morel 1998)
. New physical processes, mainly connected to macroscopic motions, must
be introduced to understand these news observations. In this poster,
we present solar models with such macroscopic motions, as turbulent
pressure in the outer layers, mixing due to the tachocline (Spiegel and
Zahn 1992), and some mixing in the core (Morel and Schatzman 1996). From
our results, we could say that: (1) Mixing in the core is unlikely (δ
c2/c2 &gt; 2%) (2) Turbulent pressure improves
the absolute value of the acoustic modes frequencies (~5 μ Hz at 4 mHz)
(3) And mixing in a tachocline of thickness of 0.05 plus or minus 0.03
Rodot (Corbard et al. 1997) looks promising.

---------------------------------------------------------
Title: Composition and Opacity in the Solar Interior
Authors: Turck-Chièze, S.
1998sce..conf..125T Altcode:
No abstract at ADS

---------------------------------------------------------
Title: High-Frequency Signals in the Power Spectrum of Integrated
Solar Velocity Observations from the GOLF Experiment
Authors: Garcia, R. A.; Pallé, P. L.; Turck-Chièze, S.; Osaki, Y.;
Shibahashi, H.; Jefferies, S.; GOLF Team
1998ESASP.418..177G Altcode: 1998soho....6..177G
The power spectrum of ~630 days of full-disk solar velocity data,
provided by the GOLF spectrophotometer aboard SOHO, has revealed
the presence of mode-like structure well beyond the acoustic cut-off
frequency for the solar atmosphere (nuac ~5.4 mHz). This
kind of structure has already been observed in intermediate and high
spatial resolution oscillation data (Duvall et al. 1991), but never
before in integrated data like BiSON or IRIS. This is probably due
to the higher level of noise that are inherent to the earth-based
experiments. In this contribution, we analyse the observed peak
structure (nuac &lt; ν &lt; 7.5 mHz) and we describe the
theoretical analysis of such signal.

---------------------------------------------------------
Title: First Results on it P Modes from GOLF Experiment
Authors: Lazrek, M.; Baudin, F.; Bertello, L.; Boumier, P.; Charra,
J.; Fierry-Fraillon, D.; Fossat, E.; Gabriel, A. H.; García, R. A.;
Gelly, B.; Gouiffes, C.; Grec, G.; Pallé, P. L.; Pérez Hernández,
F.; Régulo, C.; Renaud, C.; Robillot, J. -M.; Roca Cortés, T.;
Turck-Chièze, S.; Ulrich, R. K.
1997SoPh..175..227L Altcode:
The GOLF experiment on the SOHO mission aims to study the internal
structure of the Sun by measuring the spectrum of global oscillations
in the frequency range 10-7 to 10-2 Hz. Here
we present the results of the analysis of the first 8 months of
data. Special emphasis is put into the frequency determination of the p
modes, as well as the splitting in the multiplets due to rotation. For
both, we show that the improvement in S/N level with respect to the
ground-based networks and other experiments is essential in achieving
a very low-degree frequency table with small errors ∼ 2 parts in
10-5). On the other hand, the splitting found seems to favour
a solar core which does not rotate slower than its surface. The line
widths do agree with theoretical expectations and other observations.

---------------------------------------------------------
Title: First View of the Solar Core from GOLF Acoustic Modes
Authors: Turck-Chièze, S.; Basu, S.; Brun, A. S.;
Christensen-Dalsgaard, J.; Eff-Darwich, A.; Lopes, I.; Pérez
Hernández, F.; Berthomieu, G.; Provost, J.; Ulrich, R. K.; Baudin,
F.; Boumier, P.; Charra, J.; Gabriel, A. H.; Garcia, R. A.; Grec,
G.; Renaud, C.; Robillot, J. M.; Roca Cortés, T.
1997SoPh..175..247T Altcode:
After 8 months of nearly continuous measurements the GOLF instrument,
aboard SOHO, has detected acoustic mode frequencies of more than 100
modes, extending from 1.4 mHz to 4.9 mHz. In this paper, we compare
these results with the best available predictions coming from solar
models. To verify the quality of the data, we examine the asymptotic
seismic parameters; this confirms the improvements achieved in solar
models during the last decade.

---------------------------------------------------------
Title: Performance and Early Results from the GOLF Instrument Flown
on the SOHO Mission
Authors: Gabriel, A. H.; Charra, J.; Grec, G.; Robillot, J. -M.;
Roca Cortés, T.; Turck-Chièze, S.; Ulrich, R.; Basu, S.; Baudin,
F.; Bertello, L.; Boumier, P.; Charra, M.; Christensen-Dalsgaard, J.;
Decaudin, M.; Dzitko, H.; Foglizzo, T.; Fossat, E.; García, R. A.;
Herreros, J. M.; Lazrek, M.; Pallé, P. L.; Pétrou, N.; Renaud, C.;
Régulo, C.
1997SoPh..175..207G Altcode:
GOLF in-flight commissioning and calibration was carried out during the
first four months, most of which represented the cruise phase of SOHO
towards its final L1 orbit. The initial performance of GOLF is shown
to be within the design specification, for the entire instrument as
well as for the separate sub-systems. Malfunctioning of the polarising
mechanisms after 3 to 4 months operation has led to the adoption of an
unplanned operating sequence in which these mechanisms are no longer
used. This mode, which measures only the blue wing of the solar sodium
lines, detracts little from the detection and frequency measurements of
global oscillations, but does make more difficult the absolute velocity
calibration, which is currently of the order of 20%. Data continuity
in the new mode is extremely high and the instrument is producing
exceptionally noise-free p-mode spectra. The data set is particularly
well suited to the study of effects due to the excitation mechanism
of the modes, leading to temporal variations in their amplitudes. The
g modes have not yet been detected in this limited data set. In the
present mode of operation, there are no indications of any degradation
which would limit the use of GOLF for up to 6 years or more.

---------------------------------------------------------
Title: Tri-Phonic Helioseismology: Comparison of Solar P Modes
Observed by the Helioseismology Instruments Aboard SOHO
Authors: Toutain, T.; Appourchaux, T.; Baudin, F.; Fröhlich, C.;
Gabriel, A.; Scherrer, P.; Andersen, B. N.; Bogart, R.; Bush, R.;
Finsterle, W.; García, R. A.; Grec, G.; Henney, C. J.; Hoeksema,
J. T.; Jiménez, A.; Kosovichev, A.; Roca Cortés, T.; Turck-Chièze,
S.; Ulrich, R.; Wehrli, C.
1997SoPh..175..311T Altcode:
The three helioseismology instruments aboard SOHO observe solar p modes
in velocity (GOLF and MDI) and in intensity (VIRGO and MDI). Time series
of two months duration are compared and confirm that the instruments
indeed observe the same Sun to a high degree of precision. Power
spectra of 108 days are compared showing systematic differences between
mode frequencies measured in intensity and in velocity. Data coverage
exceeds 97% for all the instruments during this interval. The weighted
mean differences (V-I) are −0.1 µHz for l=0, and −0.16 µHz for
l=1. The source of this systematic difference may be due to an asymmetry
effect that is stronger for modes seen in intensity. Wavelet analysis
is also used to compare the shape of the forcing functions. In these
data sets nearly all of the variations in mode amplitude are of solar
origin. Some implications for structure inversions are discussed.

---------------------------------------------------------
Title: Diagnostics of the External Physical Processes from Global
Oscillations of Solar-like Stars
Authors: Lopes, Ilídio; Turck-Chieze, Sylvaine; Michel, Eric;
Goupil, Marie-Jo
1997ApJ...480..794L Altcode:
We present and discuss a method to determine the phase shift of the
global acoustic oscillations of solar-like stars. This quantity can
be used to infer the main contributors of the mechanical behavior of
the acoustic waves in the outer layers of the star as far as the energy
transport and the photospheric helium abundance are concerned. The phase
shift is obtained for the Sun and for a specific candidate, β Virginis
(HD 102870), in the perspective of interpreting the next generation of
asteroseismology measurements. It is found that the signature of the
ionization of helium is better determined in a solar-like star slightly
more massive than the Sun and that this analysis can provide a very
useful indicator of the photospheric helium content, particularly in
clusters. We also find a noticeable sensitivity to the value of the
mixing-length parameter.

---------------------------------------------------------
Title: Performance and first results from the GOLF instrument on SoHO
Authors: Gabriel, A. H.; Charra, J.; Grec, G.; Robillot, J. -M.; Roca
Cortés, T.; Turck-Chièze, S.; Ulrich, R.; Baudin, F.; Bertello,
L.; Boumier, P.; Decaudin, M.; Dzitko, H.; Foglizzo, T.; Fossat, E.;
García, R. A.; Herreros, J. M.; Lazrek, M.; Pallé, P. L.; Pétrou,
N.; Renaud, C.; Régulo, C.
1997IAUS..181...53G Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Actual Status and Early Results from GOLF Experiment on-board
SOHO
Authors: Roca Cortes, T.; Gabriel, A. H.; Charra, J.; Grec, G.; Ulrich,
R. K.; Turck-Chieze, S.; Robillot, J. M.; Boumier, P.; Regulo, C.;
Baudin, F.; Lazrek, M.; Garcia, R. A.; Palle, P. L.; GOLF Team
1997ASPC..118..249R Altcode: 1997fasp.conf..249R
GOLF is a resonant scattering spectrophotomer which is flying onboard
SOHO. The first four months were dedicated to the commissioning
and calibration of the instrument which led to the conclusion of
a performance within design specification at system and subsystem
levels. However, mal-functioning of the polarising mechanisms at the end
of this period led to the adoption of an unplanned operating sequence in
which the mechanisms are no longer used. This photometric mode, which
measures at two points on the blue wing of the solar sodium lines, has
very little effect on the possibility of reaching the first objective
of the mission: measuring the solar spectrum of normal modes. However,
the precise calibration procedure to transform the actual measurements
into velocity is not trivial. The actual operating mode allows the
obtention of continuous data without interruptions which is producing
exceptionally noise-free p-mode spectra. Although this spectrum is
being studied, the data accumulated do not allow a positive detection
of the g-mode spectrum yet. On the other hand, the present mode of
operation do not show any indication of degradation which could limit
its use for up to 6 years or more of operation.

---------------------------------------------------------
Title: Solar Neutrinos and the Solar Model
Authors: Turck-Chieze, S.
1997ndmu.conf..147T Altcode:
No abstract at ADS

---------------------------------------------------------
Title: GOLF results: today's view on the solar modes
Authors: Grec, C.; Turck-Chièze, S.; Lazrek, M.; Roca Cortés, T.;
Bertello, L.; Baudin, F.; Boumier, P.; Charra, J.; Fierry-Fraillon,
D.; Fossat, E.; Gabriel, A. H.; Garcia, R. A.; Gelly, B.; Gouiffes,
C.; Régulo, C.; Renaud, C.; Robillot, J. M.; Ulrich, R. K.
1997IAUS..181...91G Altcode:
No abstract at ADS

---------------------------------------------------------
Title: L'héliosismologie.
Authors: Lehoucq, R.; Turck-Chieze, S.
1996LAstr.110..146L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: The Sun as a laboratory: a classical or a non classical Sun?
Authors: Turck-Chieze, S.
1996NuPhS..48..350T Altcode:
In this review, I first mention the improvements in nuclear or plasma
physics which may still substantially reduce the discrepancy between
neutrino predictions and observed neutrino fluxes. Then, I examine
the questions suggested by the helioseismic present results and the
theoretical improvements which are planned to perform. Finally,
I present the next generation of the spatial experiments and the
potentiality we wait from their results.

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Title: Global Oscillations at Low Frequency from the SOHO Mission
(GOLF)
Authors: Gabriel, A. H.; Grec, G.; Charra, J.; Robillot, J. -M.; Roca
Cortés, T.; Turck-Chièze, S.; Bocchia, R.; Boumier, P.; Cantin, M.;
Cespédes, E.; Cougrand, B.; Crétolle, J.; Damé, L.; Decaudin, M.;
Delache, P.; Denis, N.; Duc, R.; Dzitko, H.; Fossat, E.; Fourmond,
J. -J.; García, R. A.; Gough, D.; Grivel, C.; Herreros, J. M.;
Lagardère, H.; Moalic, J. -P.; Pallé, P. L.; Pétrou, N.; Sanchez,
M.; Ulrich, R.; van der Raay, H. B.
1995SoPh..162...61G Altcode:
The GOLF experiment on the SOHO mission aims to study the internal
structure of the sun by measuring the spectrum of global oscillations in
the frequency range 10−7 to 10−2 Hz. Bothp
andg mode oscillations will be investigated, with the emphasis on
the low order long period waves which penetrate the solar core. The
instrument employs an extension to space of the proven ground-based
technique for measuring the mean line-of-sight velocity of the viewed
solar surface. By avoiding the atmospheric disturbances experienced
from the ground, and choosing a non-eclipsing orbit, GOLF aims to
improve the instrumental sensitivity limit by an order of magnitude
to 1 mm s−1 over 20 days for frequencies higher than
2.10−4 Hz. A sodium vapour resonance cell is used in
a longitudinal magnetic field to sample the two wings of the solar
absorption line. The addition of a small modulating field component
enables the slope of the wings to be measured. This provides not only
an internal calibration of the instrument sensitivity, but also offers a
further possibility to recognise, and correct for, the solar background
signal produced by the effects of solar magnetically active regions. The
use of an additional rotating polariser enables measurement of the
mean solar line-of-sight magnetic field, as a secondary objective.

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Title: The role of abundances in the solar interior models
Authors: Turck-Chieze, S.
1995AdSpR..15g..85T Altcode: 1995AdSpR..15...85T
I would like to show, in this review, what we have learned on the
detailed determination of the element abundances, from the observables
of the solar interior. I shall separate the discussion in two parts,
the knowledge of the heavy elements and the knowledge of the helium
content. The heavy elements determination is necessary to perform
a complete calculation of solar evolution for the nuclear energy
production (about 1-1.5%) and the transfer of energy in the radiative
regions. On the contrary, there is no assumption on the helium content
in a solar model (because it is not measured in the photosphere) and
I would like to comment on the two ways to adjust it: the total solar
evolution calculation which is constrained by the present knowledge
of the solar luminosity and age and the extraction of the acoustic
frequency phases of high degree which are sensitive to the helium
ionization zone.

---------------------------------------------------------
Title: The Screened Nuclear Reaction Rates and the Solar Neutrino
Puzzle
Authors: Dzitko, H.; Turck-Chieze, S.; Delbourgo-Salvador, P.;
Lagrange, C.
1995ApJ...447..428D Altcode:
This paper reexamines the nuclear reaction rates used for hydrogen
burning in the classical framework of stellar evolution. The
screening effect is discussed, and the formalisms generally used
appear not accurate enough for the determination of the solar neutrino
fluxes. So we analyze screening with the more realistic potential
suggested by Mitler. We compare the first-order description which
allows factorization of the screening correction with a complete
calculation in which an ellipsoidal charge distribution around
reacting ions is introduced. Since the radial deformation of the charge
distribution appears to have a small effect and is of the same order
as and of opposite sign to the dynamical effect of the surrounding
ions, we conclude that the factorized prescription of Mitler seems
really easy to implement and appropriate within 2% accuracy for the
whole hydrogen-burning phase and stellar masses between 0.6 and 20
Msun. It leads to an enhancement factor of the reaction
rates located between those of Salpeter weak screening and Graboske
et al. intermediate screening. Then we consider each reaction rate
of the p-p chain, and it appears that two reactions may still be
modified significantly beyond the "conventional error bar": the
electronic capture on 7Be and the proton interaction on
the same nucleus, both of which influence the 8B neutrino
flux. Considering reasonable variations of the nuclear reaction
rates of the p-p chains, compatible with the present experimental
and theoretical situation, the solar neutrino discrepancy between
experiments and predictions could be considerably reduced.

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Title: Corot: a Space Project Devoted to the Study of Convection
and Rotation in Stars
Authors: Catala, C.; Auvergne, M.; Baglin, A.; Bonneau, F.; Magnan,
A.; Vuillemin, A.; Goupil, M. J.; Michel, E.; Boumier, P.; Dzitko,
H.; Gabriel, A.; Gautier, D.; Lemaire, P.; Mangeney, A.; Mosser, B.;
Turck-Chiéze, S.; Zahn, J. P.
1995ESASP.376b.549C Altcode: 1995soho....2..549C; 1995help.confP.549C
No abstract at ADS

---------------------------------------------------------
Title: A Second Order Asymptotic Expression Applied to the Low Degree
Acoustic Mode Predictions
Authors: Lopes, I.; Turck-Chieze, S.
1995ASPC...76..160L Altcode: 1995gong.conf..160L
No abstract at ADS

---------------------------------------------------------
Title: Solar Modeling: Critical Look and Neutrino Puzzle
Authors: Turck-Chieze, S.; Dzitko, H.; Lopes, I.
1995ASPC...76..116T Altcode: 1995gong.conf..116T
No abstract at ADS

---------------------------------------------------------
Title: Study of the Screening Formalisms for Stellar Evolution Codes
Authors: Dzitko, H.; Turck-Chieze, S.; Delbourgo-Salvador, P.;
Lagrange, C.
1995ASPC...76..172D Altcode: 1995gong.conf..172D
No abstract at ADS

---------------------------------------------------------
Title: COROT: A Proposal to Study Stellar Convection and Internal
Rotation
Authors: Catala, C.; Mangeney, A.; Gautier, D.; Auvergne, M.; Baglin,
A.; Goupil, M. J.; Michel, E.; Zahn, J. P.; Magnan, A.; Vuillemin,
A.; Boumier, P.; Gabriel, A.; Lemaire, P.; Turck-Chieze, S.; Dzitko,
H.; Mosser, B.; Bonneau, F.
1995ASPC...76..426C Altcode: 1995gong.conf..426C
No abstract at ADS

---------------------------------------------------------
Title: The second order asymptotic theory for the solar and stellar
low degree acoustic mode predictions
Authors: Lopes, I.; Turck-Chieze, S.
1994A&A...290..845L Altcode:
We discuss the new asymptotic formulae, obtained by Tassoul and
Vorontsov without the Cowling approximation, for the acoustic modes
of low degree. We deduce second-order asymptotic expressions which
recover the absolute value of the solar calculated eigenfrequencies
within 10μHz for degrees lower than 12 and frequencies between
1mHz&lt;=ν&lt;=5mHz. This result is compared with the previous
ones obtained in a first or second-order asymptotic theories. The
different seismic parameters: {DELTA}ν_l,n_ , δ_2nu_l,n_
and δν_l,n_ , the phase shift α and its derivative β_l,n_ are
also determined and the influence of the different physical processes
are emphasized.

---------------------------------------------------------
Title: Studies on the Central Part of the Solar Model and Incidences
on Stellar Evolution
Authors: Dzitko, H.; Turck-Chièze, S.
1994emsp.conf....3D Altcode:
No abstract at ADS

---------------------------------------------------------
Title: The spatial GOLF project
Authors: Turck-Chieze, S.
1994esa..conf..532T Altcode: 1994IAUCo.147..532T
No abstract at ADS

---------------------------------------------------------
Title: Analysis of the screening formalisms in solar and stellar
conditions
Authors: Dzitko, H.; Turck-Chieze, S.; Delbourgo-Salvador, P.;
Lagrange, Ch.
1994esa..conf..601D Altcode: 1994IAUCo.147..601D
No abstract at ADS

---------------------------------------------------------
Title: The solar interior
Authors: Turck-Chièze, S.; Däppen, W.; Fossat, E.; Provost, J.;
Schatzman, E.; Vignaud, D.
1993PhR...230...57T Altcode:
This report confronts the different aspects of the solar interior from
the experimental and theoretical points of view, discussing photospheric
abundances, neutrinos and acoustic mode measurements. The theoretical
approach mainly concerns the classical framework of stellar evolution,
nevertheless, particle interpretation of the data and astrophysical
solutions invoked in the last 10 years are coherently examined.

---------------------------------------------------------
Title: Toward a Unified Classical Model of the Sun: On the Sensitivity
of Neutrinos and Helioseismology to the Microscopic Physics
Authors: Turck-Chieze, Sylvaine; Lopes, Ilidio
1993ApJ...408..347T Altcode:
This paper focuses mainly on the neutrino puzzle and discusses the
point of view that neutrinos and helioseismology are two complementary
probes of the solar interior. We first analyze the physical differences
noticed between already published solar models and their consequences
for neutrino predictions. We propose new results on the solar
neutrino predictions and acoustic mode frequencies for l = 0-150,
in the classical framework of stellar evolution. We quantify the
influence of precise composition, nuclear reaction rates, screening
effect, and opacity calculations on both neutrino and acoustic mode
frequency predictions. Our present predictions are 6.4 +/- 1.4 SNU
for the chlorine experiment, 4.4 +/- 1.1 x 10 exp 6/sq cm/s for the
water detector, and 122.5 +/- 7 SNU for the gallium detector.

---------------------------------------------------------
Title: Solar modelling and the neutrino puzzle the astrophysical
point of view
Authors: Turck-Chièze, S.
1993NuPhS..31..129T Altcode:
After short comments on the neutrino puzzle and the energy balance,
I shall discuss the impact of the improved ingredients of the solar
modelling on the solar structure, the predicted neutrino fluxes and
the acoustic frequencies determination. Progresses in the understanding
of the acoustic frequencies are clear and reinforce the idea that the
classical framework is justified, as a first approximation. Regarding
the neutrino problem, even if each modification has some impact on
different neutrino sources, altogether, they only slightly reduce
the present discrepancy, so we conclude that the main source of
the discrepancy is not yet discovered. As far as there is no clear
disagreement between the different experiments, I suggest directions
of investigations for the near future concerning the nuclear region
where the nuclear reaction rates must be revisited and concerning
phenomena not yet included in solar modelling.

---------------------------------------------------------
Title: Theoretical review
Authors: Turck-Chièze, S.
1993paas.conf...75T Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Microscopic physics in the solar standard model
Authors: Lopes, I.; Turck-Chieze, S.
1993ASPC...40...51L Altcode: 1993IAUCo.137...51L; 1993ist..proc...51L
No abstract at ADS

---------------------------------------------------------
Title: Screening effect in solar conditions.
Authors: Dzitko, H.; Delbourgo-Salvador, P.; Lagrange, C.;
Turck-Chièze, S.
1993oee..conf..388D Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Comments on solar modelling
Authors: Turck-Chieze, Sylvaine
1992NuPhS..28..116T Altcode:
In this contribution, I compare what we learn from
detected solar neutrino fluxes on earth and what we learn from
helioseismology. Contrary to the first impression that helioseismology
is in better agreement with theoretical predictions, I insist on the
fact that the deduced uncertainty on the thermodynamical quantities
is of the same order. Then I take the example of cosmions to examine
the lesson of extra hypothesis on classical framework of stellar
evolution in order to conclude on the astrophysical perspectives and
the problems open.

---------------------------------------------------------
Title: The classical solar model and beyond this framework.
Authors: Turck-Chièze, S.
1992pnap.conf....3T Altcode:
From the comparison of recent updated solar model predictions, the
extreme sensitivity of the 8B neutrino flux to opacity
coefficients, to some specific reactions and to the screening effect
is once more illustrated.

---------------------------------------------------------
Title: A Critical Look at Cosmions
Authors: Kaplan, Jean; Martin de Volnay, Francois; Tao, Charling;
Turck-Chieze, Sylvaine
1991ApJ...378..315K Altcode:
A thorough numerical investigation of the cosmion hypothesis as a
solution to the solar neutrino puzzle was performed using the Saclay
solar evolution code. The ensuing constraints on cosmion parameters
appear as domains in the plane of cosmion-proton cross section
versus cosmion mass. Various hypotheses on cosmion couplings are
considered. Comparison with available experimental data on direct dark
matter detection excludes most of the domain in the 'vector' case. In
the 'axial' case the results provide useful hints for experiments. The
effect of cosmions on the sound speed near the center of the sun,
confronted with present knowledge and data on helioseismology,
does not improve the comparison between standard predictions and
helioseismological inversion.

---------------------------------------------------------
Title: A critical look at cosmions.
Authors: Kaplan, J.; de Volnay, F. M.; Tao, C.; Turck-Chièze, S.
1990clac.book.....K Altcode:
The authors have performed a numerical investigation of the cosmion
hypothesis as a solution to the solar neutrino puzzle, using the Saclay
solar evolution code. The ensuing constraints on cosmion parameters
appear as domains in the plane of cosmion-proton cross-section
versus cosmion mass. Various hypothesis on cosmion couplings are
considered. Comparison with available experimental data on direct
dark matter detection excludes most of the domain in the "vector"
case. In the "axial" case the results provide useful hints for
experiments. Finally the effect of cosmions on the sound speed near
the center of the sun is confronted with present knowledge and data
on helioseismology.

---------------------------------------------------------
Title: WIMPS and Solar Evolution Code
Authors: Giraud-Heraud, Yannick; Kaplan, Jean; de Volnay, Francois
Martin; Tao, Charling; Turck-Chieze, Sylvaine
1990SoPh..128...21G Altcode: 1990IAUCo.121P..21G
The Saclay solar evolution code is used to check the effect of WIMPs on
solar evolution. In this paper we study the effects of various types
of Cosmion-matter interactions, give constraints on the crosssections
compatible with the measured neutrino rate of 2 SNU on chlorine, and
relate these constraints to ongoing dark matter detection experiments.

---------------------------------------------------------
Title: Metallicity, opacity coefficients and the solar standard model
Authors: Courtaud, D.; Damamme, G.; Genot, E.; Vuillemin, M.;
Turck-Chieze, Sylvaine
1990SoPh..128...49C Altcode: 1990IAUCo.121P..49C
We discuss the effect of the uncertainties affecting the opacities
on the derived characteristics of the Sun. We consider two sources
of uncertainty: the relative composition of the Sun at birth and the
difference between two opacity calculations. As an illustration, we
discuss the effect of the choice of photospheric or meteoritic iron
abundance on the predicted chlorine neutrino capture rate and present
comparisons between the Los Alamos and Limeil opacity calculations.

---------------------------------------------------------
Title: Progress in solar modeling
Authors: Turck-Chieze, S.
1990nep..conf..571T Altcode:
No abstract at ADS

---------------------------------------------------------
Title: On the Accuracy of Solar Modelling
Authors: Turck-Chièze, Sylvaine
1990ASSL..159..125T Altcode: 1990insu.conf..125T; 1990IAUCo.121..125T
No abstract at ADS

---------------------------------------------------------
Title: Revisiting the Standard Solar Model
Authors: Turck-Chieze, S.; Cahen, S.; Casse, M.; Doom, C.
1988ApJ...335..415T Altcode:
The authors investigate the mutual consistency between contemporary
standard solar models, based on the recent Los Alamos opacity
tables. Satisfactory agreement is found among these models concerning
the helium content and the neutrino capture rates, considering the
extreme sensitivity of the 8B neutrino flux to central
conditions of the Sun. The authors' reference model leads to a solar
helium content of 0.276±0.012 by mass fraction, a capture rate of
5.8±1.3 SNU on 37Cl and 125±5 SNU on 71Ga.

---------------------------------------------------------
Title: High mass loss in the young Sun!
Authors: Turck-Chieze, S.; Daeppen, W.; Casse, M.
1988ESASP.286..629T Altcode: 1988ssls.rept..629T
The consequences of a possible mass loss in the early main sequence
stage of solar type stars are investigated. Special attention is
given to the Sun, the constraints from surface abundances and p-mode
observations are taken into account. Only a total mass loss smaller
than 0.2 Msun seems to be consistent with the
observations. Though the ensuing modifications of the internal structure
and the cosmological consequences are very small, the 3He,
7Li, 9Be surface abundances are significantly
modified.

---------------------------------------------------------
Title: Modelling the variation of solar p-mode frequencies.
Authors: Daeppen, W.; Gough, Douglas O.; Turck-Chieze, S.
1988ESASP.286..511D Altcode: 1988ssls.rept..511D
The authors present a Green's function technique to study long-term
variations of the Sun (with characteristic time scales from one month
to millions of years). The method is the combination of two previous
analyses carried out independently by Gough and by Däppen. Their study
has been motivated by the recent observational progress on solar p-mode
frequency variations.

---------------------------------------------------------
Title: The interior of the Sun: from observations to theory.
Authors: Turck-Chièze, S.
1988ffnp.conf..165T Altcode:
Precise observations (surface abundances, neutrino fluxes detection,
seismology) and laboratory measurements (nuclear reactions rates)
constrain and guide the standard model of the Sun and by this way test
the first stage of stellar evolution. A review of the situation is
proposed enlightened by the agreement between the most detailed and
updated standard models published. A discussion on the incidence of
non-standard physics is also given.

---------------------------------------------------------
Title: Étude de l'électrodésintégration du deutérium ²H(ee'p)n
dans un large domaine d'inélasticité et pour des impulsions
de recul du neutron allant de 0 à 500 MeV/c

---------------------------------------------------------
Title: Étude de
l'électrodésintégration du deutérium ²H(ee'p)n dans un large
domaine d'inélasticité et pour des impulsions de recul du neutron
allant de 0 à 500 MeV/c

---------------------------------------------------------
Title: Study on the deuterium electrodecay
²H(ee'p)n in a large inelasticity range and for recoil neutron
momenta from 0 to 500 MeV/c;
Authors: Turck-Chièze, Sylvaine
1985PhDT........65T Altcode:
No abstract at ADS