lemaire

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Author name code: lemaire
ADS astronomy entries on 2022-09-14
author:"Lemaire, Philippe"

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Title: State-of-the-art of photorefractive holographic interferometry
and potentialities for space applications
Authors: Georges, Marc; Lemaire, Philippe; Pauliat, Gilles; Launay,
Jean-Claude; Roosen, Gérald
2018SPIE10570E..1GG Altcode:
This paper, "State-of-the-art of photorefractive holographic
interferometry and potentialities for space applications," was presented
as part of International Conference on Space Optics—ICSO 1997,
held in Toulouse, France.

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Title: EUV imager and spectrometer for LYOT and solar orbiter space
missions
Authors: Millard, Anne; Lemaire, Philippe; Vial, Jean-Claude
2017SPIE10568E..0RM Altcode:
In the 2010 horizon, solar space missions such as LYOT and Solar
Orbiter will allow high cadence UV observations of the Sun at spatial
and spectral resolution never obtained before. To reach these goals,
the two missions could take advantage of spectro-imagers. A reflective
only optical solution for such an instrument is described in this
paper and the first results of the mock-up being built at IAS are shown.

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Title: Prospects for the design of an ultraviolet imaging Fourier
transform spectrometer
Authors: Lemaire, Philippe
2017SPIE10569E..13L Altcode:
Recent results from solar observations in the far and extremeultraviolet
(FUV/EUV) obtained from SOHO (SOlar and Heliospheric Observatory)
and TRACE (Transition Region Camera) show the extreme variability of
the solar atmosphere. Within the limited resolution of the instruments
(1-2 arcseconds) horizontal and vertical velocities up-to 100 to 400
km s-1 have been measured. With an horizontal velocity
of 100 km s-1 an one arsecond structure crosses the one
arcsecond slit width of a classical slit spectrometer in less than
10 seconds. In the future, with higher angular resolution (e.g. 0.1
arcsecond), the capability to study small structures will be greatly
reduced by a classical slit spectrometer. To be able to characterize the
small scale solar atmospheric structures formed in the 104
K to 106 K temperature range (which emit in the 30 to 180
nm wavelength range) a spectrometer without slit (or with wide slit)
is required. At the same time to obtain an accurate measurement of
the doppler velocity an high spectral resolution is needed. The two
requirements, high spectral resolution and large slit, are difficult
to be simultaneously fulfilled with a classical slit spectrometer
within the limited volume of a space instrumentation. Also, we propose
to use an Imaging Fourier Transform Spectrometer (IFTS) to provide
simultaneously a bidimensionnal field and an accurate determination
of line profiles and positions. The development of Fourier Transform
Spectrometers (FTS), although popular in the infrared, has been
very limited in the UV/FUV by the lack of very high quality beam
splitter. Since 10 years, the use of diffraction gratings as beam
splitters has been suggested and few intruments have been built
([Chak 94]; [Clea 92]; [File 00]). These instruments illustrate some
applications in the new wavelength domain opened by using a beam
splitter grating, but do not yet provide the full capabilities of an
FTS. In this paper we present several optical schemes which can provide
the full capabilities of a complete IFTS in the FUV/EUV spectral range.

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Title: Development of optical ground verification method for μm to
sub-mm reflectors
Authors: Stockman, Y.; Thizy, C.; Lemaire, P.; Georges, M.; Mazy,
E.; Mazzoli, A.; Houbrechts, Y.; Rochus, P.; Roose, S.; Doyle, D.;
Ulbrich, G.
2017SPIE10568E..1KS Altcode:
Large reflectors and antennas for the IR to mm wavelength range
are being planned for many Earth observation and astronomical
space missions and for commercial communication satellites as
well. Scientific observatories require large telescopes with precisely
shaped reflectors for collecting the electro-magnetic radiation from
faint sources. The challenging tasks of on-ground testing are to
achieve the required accuracy in the measurement of the reflector
shapes and antenna structures and to verify their performance under
simulated space conditions (vacuum, low temperatures). Due to the
specific surface characteristics of reflectors operating in these
spectral regions, standard optical metrology methods employed in
the visible spectrum do not provide useful measurement results. The
current state-of-the-art commercial metrology systems are not able
to measure these types of reflectors because they have to face the
measurement of shape and waviness over relatively large areas with a
large deformation dynamic range and encompassing a wide range of spatial
frequencies. 3-D metrology (tactile coordinate measurement) machines
are generally used during the manufacturing process. Unfortunately,
these instruments cannot be used in the operational environmental
conditions of the reflector. The application of standard visible
wavelength interferometric methods is very limited or impossible due
to the large relative surface roughnesses involved. A small number
of infrared interferometers have been commercially developed over
the last 10 years but their applications have also been limited
due to poor dynamic range and the restricted spatial resolution of
their detectors. These restrictions affect also the surface error
slopes that can be captured and makes their application to surfaces
manufactured using CRFP honeycomb technologies rather difficult
or impossible. It has therefore been considered essential, from the
viewpoint of supporting future ESA exploration missions, to develop and
realise suitable verification tools based on infrared interferometry
and other optical techniques for testing large reflector structures,
telescope configurations and their performances under simulated space
conditions. Two methods and techniques are developed at CSL. The
first one is an IR-phase shifting interferometer with high spatial
resolution. This interferometer shall be used specifically for the
verification of high precision IR, FIR and sub-mm reflector surfaces
and telescopes under both ambient and thermal vacuum conditions. The
second one presented hereafter is a holographic method for relative
shape measurement. The holographic solution proposed makes use of a
home built vacuum compatible holographic camera that allows displacement
measurements from typically 20 nanometres to 25 microns in one shot. An
iterative process allows the measurement of a total of up to several
mm of deformation. Uniquely the system is designed to measure both
specular and diffuse surfaces.

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Title: Definition of a metrology servo-system for a solar imaging
fourier transform spectrometer working in the far UV (IFTSUV)
Authors: Ruiz de Galarreta Fanju, C.; Philippon, A.; Bouzit, M.;
Appourchaux, T.; Vial, J. -C.; Maillard, J. -P.; Lemaire, P.
2017SPIE10564E..3ER Altcode:
The understanding of the solar outer atmosphere requires a simultaneous
combination of imaging and spectral observations concerning the far UV
lines that arise from the high chromospheres up to the corona. These
observations must be performed with enough spectral, spatial and
temporal resolution to reveal the small atmospheric structures and to
resolve the solar dynamics. An Imaging Fourier Transform Spectrometer
working in the far-UV (IFTSUV, Figure 1) is an attractive instrumental
solution to fulfill these requirements. However, due to the short
wavelength, to preserve IFTSUV spectral precision and Signal to Noise
Ratio (SNR) requires a high optical surface quality and a very accurate
(linear and angular) metrology to maintain the optical path difference
(OPD) during the entire scanning process by: optical path difference
sampling trigger; and dynamic alignment for tip/tilt compensation
(Figure 2).

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Title: Hydrogen Ly-α and Ly-β full Sun line profiles observed with
SUMER/SOHO (1996-2009)
Authors: Lemaire, P.; Vial, J. -C.; Curdt, W.; Schühle, U.;
Wilhelm, K.
2015A&A...581A..26L Altcode:
Context. Accurate hydrogen spectra emitted by the entire solar disc in
the Ly-α and Ly-βlines are valuable for deriving the distribution and
the behaviour of atomic hydrogen in the heliosphere, for understanding
the UV emissions of solar type stars better, and finally for estimating
the solar energy input that mainly initiates the chemical processes
occurring in the planetary and cometary outer atmospheres. Aims:
In this paper we want to accurately determine the irradiance solar
spectral profiles of Ly-α and Ly-β and their evolution through the
solar activity cycle 23. Methods: The SUMER/SOHO spectrometer is
a slit spectrometer that is only able to analyse a small part of the
solar image. Consequently, we used the scattered light properties of
the telescope to obtain average spectra over the solar disc. Then the
profile is calibrated using the SOLSTICE/UARS and TIMED/SEE irradiance
spectra. Results: We obtained a set of irradiance Ly-α and
Ly-β solar spectra with a 0.002 nm resolution through the solar
activity cycle 23. In each line a relation between the integrated
profile and the line centre intensity was obtained.Knowing the line
irradiance, it is possible to deduce the central line profile intensity,
a critical input into the interplanetary and planetary oxygen and
hydrogen fluorescent processes. Conclusions: The observation
of H i Ly-α and Ly-β line profiles by SUMER/SOHO during the cycle
23 allows analysis of the evolution of their characteristics and
accurate determination of UV radiation input into the solar system. Profiles are only available at the CDS via anonymous ftp to <A
href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
(ftp://130.79.128.5) or via <A
href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/581/A26">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/581/A26</A>

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Title: VizieR Online Data Catalog: Sun hydrogen Lyman irradiance
lines profiles (Lemaire+, 2015)
Authors: Lemaire, P.; Vial, J. -C.; Curdt, W.; Schuhle, U.; Wilhelm, K.
2015yCat..35810026L Altcode:
Set of irradiance Ly-α and Ly-β solar spectra with a 0.002nm
resolution through the solar activity cycle 23. The wavelength distance
from line center is given every 0.001nm. (2 data files).

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Title: The SUMER Data in the SOHO Archive
Authors: Curdt, W.; Germerott, D.; Wilhelm, K.; Schühle, U.; Teriaca,
L.; Innes, D.; Bocchialini, K.; Lemaire, P.
2014SoPh..289.2345C Altcode: 2013arXiv1309.1314C
We have released an archive of all observational data of the VUV
spectrometer Solar Ultraviolet Measurements of Emitted Radiation
(SUMER) on SOHO that have been acquired until now. The operational
phase started with `first light' observations on 27 January 1996 and
will end in 2014. Future data will be added to the archive when they
become available. The archive consists of a set of raw data (Level
0) and a set of data that are processed and calibrated to the best
knowledge we have today (Level 1). This communication describes step
by step the data acquisition and processing that has been applied in an
automated manner to build the archive. It summarizes the expertise and
insights into the scientific use of SUMER spectra that has accumulated
over the years. It also indicates possibilities for further enhancement
of the data quality. With this article we intend to convey our own
understanding of the instrument performance to the scientific community
and to introduce the new, standard FITS-format database.

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Title: The solar hydrogen Lyman α to Lyman β line ratio
Authors: Lemaire, P.; Vial, J. -C.; Curdt, W.; Schühle, U.; Woods,
T. N.
2012A&A...542L..25L Altcode:
 Aims: We investigate the variation in the solar hydrogen Lyman
α (Lyα) to Lyman β (Lyβ) line ratio as a function of the solar
activity by taking into account new results obtained by SoHO/SUMER
and TIMED/SEE. Methods: We reanalyze data of quiet and active
regions previously collected with the LPSP multichannel instrument on
OSO8. We then re-examine data obtained on the solar disk with SUMER
and compare them with previous data. In a second step, we use the
full Sun H i Lyβ profiles to determine the Lyβ contribution to the
SEE profiles obtained with a 0.4 nm full width at half-maximum. The
variation in the Lyα to Lyβ line ratio is then measured for part
of the solar cycle 23 (2002-2008). Results: We determine the
radiance line ratio of the solar H i Lyα to Lyβ line for a quiet Sun
area and the relation between the ratio of the Lyα to Lyβ irradiance
and the Lyα solar irradiance.

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Title: Definition of an imaging spectrometer meeting the needs of
UV solar physics
Authors: Ruiz de Galarreta Fanjul, C.; Philippon, A.; Vial, J. -C.;
Lemaire, P.; Maillard, J. -P.; Buisset, C.; Appourchaux, T.;
Auchère, F.
2010SPIE.7732E..36R Altcode: 2010SPIE.7732E..99R
The study of the outer solar atmosphere requires combining imaging
and spectroscopy in the UV lines formed in the high chromosphere,
the transition region and the corona. We start from the science
requirements and we define the instrumental specifications in terms
of field-of-view (FOV), spatial, temporal and spectral resolution and
bandpass. We propose two different all-reflection optical architectures
based on interferometric techniques: Spatial Heterodyne Spectroscopy
(SHS); and Imaging Transform Spectrometer (IFTS). We describe the
different set-ups and compare the potential performances of the two
types of solutions, and discuss their feasibility. We conclude that
IFTS appears to be the best solution, meeting the needs of UV solar
physics. However, we point out the many difficulties to be encountered,
especially as far as metrology is concerned.

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Title: Space telescopes
Authors: Lemaire, Philippe; Aschenbach, Bernd; Seely, John F.
2010ISSIR...9..165L Altcode:
A brief survey of normal and grazing incidence space telescope types
is given. The optimization of telescope efficiency either by dedicated
single, bi-layer or multilayer coatings is described. An outlook of
solar and stellar coronagraphs is included.

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Title: Normal- and grazing-incidence gratings and mountings used
in space
Authors: Lemaire, Philippe
2010ISSIR...9..193L Altcode:
In most spectrometers, the grating is the component chosen to give
the necessary spectral resolution either to filter the wavelength band
or to obtain the line profiles. An overview of the grating properties
and mountings used in space instrumentation is given.

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Title: The Ly-α profile and center-to-limb variation of the quiet Sun
Authors: Curdt, W.; Tian, H.; Teriaca, L.; Schühle, U.; Lemaire, P.
2008A&A...492L...9C Altcode: 2008arXiv0812.1441C
Aims: We study the emission of the hydrogen Lyman-α line in the quiet
Sun, its center-to-limb variation, and its radiance distribution. We
also compare quasi-simultaneous Ly-α and Ly-β line profiles. Methods: We used the high spectral and spatial resolution of the
SUMER spectrometer and completed raster scans at various locations
along the disk. For the first time, we used a method to reduce the
incoming photon flux to a 20%-level by partly closing the aperture
door. We also performed a quasi-simultaneous observation of both Ly-α
and Ly-β at the Sun center in sit-and-stare mode. We infer the flow
characteristic in the Ly-α map from variations in the calibrated λ
1206 Si iii line centroids. Results: We present the average
profile of Ly-α, its radiance distribution, its center-to-limb
behaviour, and the signature of flows on the line profiles. Little
center-to-limb variation and no limb brightening are observed in the
profiles of the Ly-α line. In contrast to all other lines of the
Lyman series, which have a red-horn asymmetry, Ly-α has a robust and
- except for dark locations - dominating blue-horn asymmetry. There
appears to be a brightness-to-asymmetry relationship. A similar
and even clearer trend is observed in the downflow-to-asymmetry
relationship. This important result is consistent with predictions
from models that include flows. However, the absence of a clear
center-to-limb variation in the profiles may be more indicative of
an isotropic field than a mainly radial flow. Conclusions: It
appears that the ubiquitous hydrogen behaves in a similar way to a
filter that dampens all signatures of the line formation by processes
in both the chromosphere and transition region.

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Title: The line profile and center-to-limb variation of quiet-Sun
Lyman-alpha emission
Authors: Curdt, W.; Tian, H.; Teriaca, L.; Schühle, U.; Lemaire, P.
2008ESPM...12.2.91C Altcode:
We study the emission of the hydrogen Lyman-alpha line in the quiet
Sun, its center-to-limb variation, and its radiance distribution, which
we also compare to the Lyman-beta line. We use the high spectral and
spatial resolution of the SUMER spectrometer and take raster scans at
various locations on the disk. For the first time, we have used a new
method to reduce the incoming photon flux to a 20%-level by partly
closing the aperture door. We also performed a quasi-simultaneous
observation of both Ly-a and Ly-b at Sun centre in sit-and-stare
mode. We deduce the flow characteristic in Ly-a map from variations of
the calibrated Si III line centroids. We present the average profile
of Ly-a, its radiance distribution, its center-to-limb behaviour,
and the signature of flows on the line profiles. Different from all
other lines of the Lyman series, which have a red-horn asymmetry, Ly-a
has a robust and dominating blue-horn asymmetry. To our knowledge,
this result is only predicted by models which include flows.

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Title: Rewritable VPHGs based on photochromic materials
Authors: Bianco, Andrea; Toso, Giorgio; Dassa, Giovanni; Chiara,
Bertarelli; Molinari, Emilio; Zerbi, Filippo M.; Zerbi, Giuseppe;
Georges, Marc; Lemaire, Philippe
2008SPIE.7018E..2MB Altcode: 2008SPIE.7018E..85B
Volume phase holographic gratings (VPHGs) are becoming an
interesting alternative to the ruled gratings in modern astronomical
instrumentation. Photochromic materials with thermal stability are
good candidates for the development of holographic optical elements and
in particular for VPHGs. VPHGs based on photochromic materials can be
written and erased many times without the degradation of the material;
moreover the material does not need any developing process after the
exposure, making the writing process very simple. We have already
studied photochromic materials for this aim in the framework of the
JRA6 (Opticon Project, FP6) and we found that large modulations of the
refractive index can be achieved using diarylethene polymers. Going
from the materials characterization to technology, substrates with
larger thickness and good optical properties are required. Herein we
present the development of new technique to tailor the thickness of
the photochromic films in two ranges: 5 - 30 micron and 700 - 1000
micron. The former are suitable for the development of broadband
VPHGs, whereas the latter are suitable for narrow band tunable
filters application. Details on the optical properties of the films
are reported. Finally, a holographic set-up based on an Ar+ laser has
been optimized in order to write the gratings.

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Title: Performances of NIR VPHGs at cryogenic temperatures
Authors: Insausti, M.; Garzón, F.; Rasilla, J. L.; Blanche, P. -A.;
Lemaire, P.
2008SPIE.7018E..4TI Altcode: 2008SPIE.7018E.154I
We summarize the performances measured at room temperature and in
cryogenic conditions of a set of NIR Volume Phase Holographic Gratings
(VPHGs) which can then be used in astronomical instrumentations. VPHGs
are novel optical components which can replace standard transmission
gratings. Instead of a surface modulation a diffraction index
modulation printed in a volume of material generates the diffraction
according to the required specifications. Results on transmission and
wavefront deformation are presented and compared in the two temperature
regimes. These results were achieved along the run of the Joint Research
Action 6 of OPTICON FP6 programme whose participating institutions are
Osservatorio Astronomico di Brera (INAF), Instituto de Astrofísica de
Canarias, Centre Spatial de Liege, Politecnico di Milano and European
Southern Observatory.

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Title: WIYN bench upgrade: a revitalized spectrograph
Authors: Bershady, M.; Barden, S.; Blanche, P. -A.; Blanco, D.;
Corson, C.; Crawford, S.; Glaspey, J.; Habraken, S.; Jacoby, G.; Keyes,
J.; Knezek, P.; Lemaire, P.; Liang, M.; McDougall, E.; Poczulp, G.;
Sawyer, D.; Westfall, K.; Willmarth, D.
2008SPIE.7014E..0HB Altcode: 2008SPIE.7014E..15B
We describe the redesign and upgrade of the versatile fiber-fed Bench
Spectrograph on the WIYN 3.5m telescope. The spectrograph is fed
by either the Hydra multi-object positioner or integral-field units
(IFUs) at two other ports, and can be configured with an adjustable
camera-collimator angle to use low-order and echelle gratings. The
upgrade, including a new collimator, charge-coupled device (CCD) and
modern controller, and volume-phase holographic gratings (VPHG), has
high performance-to-cost ratio by combining new technology with a system
reconfiguration that optimizes throughput while utilizing as much of the
existing instrument as possible. A faster, all-refractive collimator
enhances throughput by 60%, nearly eliminates the slit-function due
to vignetting, and improves image quality to maintain instrumental
resolution. Two VPH gratings deliver twice the diffraction efficiency
of existing surface-relief gratings: A 740 l/mm grating (float-glass and
post-polished) used in 1st and 2nd-order, and a large 3300 l/mm grating
(spectral resolution comparable to the R2 echelle). The combination of
collimator, high-quantum efficiency (QE) CCD, and VPH gratings yields
throughput gain-factors of up to 3.5.

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Title: Solar prominence properties derived from the UV-EUV SUMER
spectral atlas
Authors: Parenti, S.; Vial, J. -C.; Lemaire, P.
2008AdSpR..41..144P Altcode:
In this paper, we summarize the work done to build a UV-EUV spectral
atlas of a prominence and we introduce some recent scientific
results obtained from these data. For this work we used SOHO/SUMER
data covering the full wavelength range accessible by the instrument
(from about 800 to 1600 Å), when a prominence and the quiet Sun (used
as spectral reference) were observed in October 1998. We present here
only a fraction of the data, which results in the analysis of more
than 600 spectral lines, including some new identifications. Here we
also present the differential emission measure obtained from the data,
both for the quiet Sun and the prominence. The main differences in
characteristics are discussed.

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Title: A Contribution to the Understanding of Chromospheric
Oscillations
Authors: Baudin, F.; Ibarra, E.; Avrett, E. H.; Vial, J. -C.;
Bocchialini, K.; Costa, A.; Lemaire, P.; Rovira, M.
2007SoPh..241...39B Altcode:
We present SUMER/SOHO UV measurements of chromospheric oscillations
of intensity, velocity, and linewidth observed in C I, S I, O I, and
C II lines, which are formed in the altitude range from 1000 km to
2000 km above τ500=1. Oscillations in lines originating
at similar altitudes exhibit different behaviors which we discuss in
terms of the formation of the lines.

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Title: Quiet sun XUV and EUV spectroscopy
Authors: Lemaire, P.
2007AdSpR..39.1876L Altcode:
The two XUV-EUV spectrometers on SOHO have collected a large amount
of data in the 6000-10 6 K solar plasma temperature
range. These data have allowed us to greatly enhance our knowledge of
the processes acting in the solar atmosphere, from the chromosphere
to the corona. Some results on the quiet Sun structure (network,
quiet Sun versus coronal hole), on the dynamics (velocities, waves,
transient events), and the main characteristics of the quiet Sun
atmosphere are presented and discussed.

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Title: IFTSUV: an imaging Fourier transform spectrometer in UV for
the next solar space missions
Authors: Millard, Anne A.; Lemaire, Philippe; Vial, Jean-Claude
2006SPIE.6266E..2GM Altcode: 2006SPIE.6266E..72M
The study of the Sun in the UV spectral domain is essential for
a better understanding of the physical processes taking place in
the solar atmosphere. The main tools for this study are imagers
and spectrometers. Nevertheless, the analysis of imagery data is
rapidly limited unless spectral information is available, and the
association of spectrometers and imagers is limited by the lack of
coherence between the instruments. Therefore, the design of an imaging
spectrometer in UV is a priority for solar physicists. In the far UV,
only all reflective optical systems can be used thus an imaging Fourier
transform spectrometer (IFTS) is the ideal candidate for the realization
of such an instrument. The performances of an IFTS are given by the
modulation efficiency. Theoretical study of performances and scientific
objectives lead to technical and operating specifications. A mock-up of
an IFTSUV has been built at IAS to validate the working principle. Its
optical design and alignment are described in this paper. The first
results are shown and discussed. Planned modifications of the design
are also discussed.

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Title: A statistical study of SUMER spectral images: events,
turbulence, and intermittency
Authors: Buchlin, E.; Vial, J. -C.; Lemaire, P.
2006A&A...451.1091B Altcode: 2005astro.ph.11042B
We analyze a series of full-Sun observations performed with the
SoHO/SUMER instrument between March and October 1996. Some parameters
(radiance, shift and width) of the S vi 93.3 nm , S vi 94.4 nm ,
and Ly \varepsilon line profiles were computed on board. Radiances
and line-of-sight velocities in a large central region of the Sun
are studied statistically: distributions of solar structures, field
Fourier spectra and structure functions are obtained. The structures
have distributions with power-law tails, the Fourier spectra of the
radiance fields also display power laws, and the normalized structure
functions of the radiance and velocity fields increase at small
scales. These results support the idea of the existence of small
scales, created by turbulence, and of intermittency of the observed
fields. These properties may provide insight into the processes needed
for heating the transition region, or, if confirmed in the corona,
the corona itself. The difficulties encountered in this analysis,
especially for the velocity data, underline the need for sensitive
ultraviolet imaging spectrometers.

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Title: Solar Hydrogen Lyman Contimuum Observations with Soho/sumer
Authors: Parenti, S.; Vial, J. -C.; Lemaire, P.
2005ESASP.600E..93P Altcode: 2005ESPM...11...93P; 2005dysu.confE..93P
No abstract at ADS

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Title: Prominence atlas in the SUMER range 800-1250 Å. II. Line
profile properties and ions identifications
Authors: Parenti, S.; Vial, J. -C.; Lemaire, P.
2005A&A...443..679P Altcode:
We present a SOHO/SUMER spectral atlas in the 800-1250 Å range of
a prominence and a Quiet Sun (QS) region observed in 1999. The atlas
is produced for two separate areas of the prominence. The QS spectrum
is used as a reference. This is the first prominence atlas obtained
with high spectral resolution (≈0.044 Å). It provides information
concerning more than 550 line profiles, in terms of position, total
radiance, and FWHM, along with the ion identification. Forty new lines
have been identified with respect to previously published spectra.

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Title: A new relation between the central spectral solar H I Lyman
α irradiance and the line irradiance measured by SUMER/SOHO during
the cycle 23
Authors: Emerich, Claude; Lemaire, Philippe; Vial, Jean-Claude; Curdt,
Werner; Schühle, Udo; Wilhelm, Klaus
2005Icar..178..429E Altcode:
The spectral irradiance at the center of the solar H I Lyman α
( λ=121.5664nm, referred to as Lyα in this paper) line profile
is the main excitation source responsible for the atomic hydrogen
resonant scattering of cool material in our Solar System. It has
therefore to be known with the best possible accuracy in order to
model the various Lyα emissions taking place in planetary, cometary,
and interplanetary environments. Since the only permanently monitored
solar irradiance is the total one (i.e. integrated over the whole
Lyα line profile), Vidal-Madjar [1975. Evolution of the solar Lyman
alpha flux during four consecutive years. Solar Phys. 40, 69-86] using
Orbiting Solar Observatory 5 (OSO-5) satellite Lyα data, established
a semi-empirical formula allowing him to deduce the central spectral
Lyα irradiance from the total one. This relation has been extensively
used for three decades. But, at the low altitude of the OSO-5 orbit,
the central part of the solar line profile was deeply absorbed by a
large column of exospheric atomic hydrogen. Consequently, the spectral
irradiance at the center of the line was obtained by a complex procedure
confronting the observations with simulations of both the geocoronal
absorption and the self-reversed shape of the solar Lyα profile. The
SUMER spectrometer onboard SOHO positioned well outside the hydrogen
geocorona, provided full-Sun Lyα profiles, not affected by such an
absorption [Lemaire et al., 1998. Solar H I Lyman α full disk profile
obtained with the SUMER/SOHO spectrometer. Astron. Astrophys. 334,
1095-1098; 2002. Variation of the full Sun Hydrogen Lyman α and β
profiles with the activity cycle. Proc. SOHO 11 Symposium, ESA SP-508,
219-222; 2004. Variation of the full Sun Hydrogen Lyman profiles
through solar cycle 23. COSPAR 2004 Meeting], making it—for the first
time—possible to measure the spectral and total Lyα solar irradiances
directly and simultaneously. A new relation between these two quantities
is derived in an expression that is formally similar to the previous
one, but with significantly different parameters. After having discussed
the potential causes for such differences, it is suggested that the
new relation should replace the old one for any future modeling of the
numerous Lyα absorptions and emissions observed in the Solar System.

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Title: Solar hydrogen-Lyman continuum observations with SOHO/SUMER
Authors: Parenti, S.; Lemaire, P.; Vial, J. -C.
2005A&A...443..685P Altcode:
In this work we analyze the emission of the H Lyman continuum (HI
LyC) in the Quiet Sun (QS) and a solar prominence, in order to derive
information on the temperature of the emitting plasma. We used the
spectral atlas obtained with SOHO/SUMER detector A in 1999 (Parenti
et al. 2005, A&amp;A, 443, 679). The high spectral resolution of this
instrument allows a good selection of the continuum, free from emission
lines. However, in the HI LyC wavelength domain, the data suffer from
large radiometric uncertainties, which lead us to use detector B as
a reference. We obtained electron temperatures of 8281 K ± 280 K and
7564 K ± 230 K in two separate parts of the prominence.

---------------------------------------------------------
Title: Dynamic holography for the space qualification of large
reflectors
Authors: Thizy, C.; Stockman, Y.; Doyle, D.; Lemaire, P.; Houbrechts,
Y.; Georges, M.; Mazzoli, A.; Mazy, E.; Tychon, I.; Ulbrich, G.
2005SPIE.5965..269T Altcode:
The next generation of infrared - sub mm space telescopes requires
reflectors with large dimensions, high quality and, according to
weight issues, are based on composite or new materials technology. The
challenging tasks of on-ground testing are to achieve the required
accuracy in the measurement of these reflectors shape and antenna
structures and to verify their performance under simulated space
conditions (vacuum, low-high temperatures). A holographic camera for
the verification and validation of this type of reflector in a space
environment is presented. A diffuser is implemented to measure the
deformations of reflective surfaces in a more flexible way. The system
has been made compatible with the vacuum conditions. Some elements of
the holographic camera (camera lenses, CCD, crystal, optical fibre) have
been adapted and tested under vacuum. The metrological certification
of the whole system is realised by the measurement of a parabolic
CFRP reflector with a 1.1 meter diameter. The results are compared to
the one achieved with a high spatial resolution IR interferometer on
the same reflector in laboratory conditions and under thermal vacuum
conditions. This later test consists in measuring the deformations
of the reflector between an initial state at a selected temperature
and a final state at another temperature. The comparison between the
high spatial resolution IR interferometer and this dynamic holographic
method showed very good qualitative and quantitative agreement between
the techniques, thus verifying the potential of this new Holographic
approach.

---------------------------------------------------------
Title: On the nature of the unidentified solar emission near 117 nm
Authors: Wilhelm, K.; Schühle, U.; Curdt, W.; Hilchenbach, M.;
Marsch, E.; Lemaire, P.; Bertaux, J. -L.; Jordan, S. D.; Feldman, U.
2005A&A...439..701W Altcode:
Spectral observations of the Sun in the vacuum-ultraviolet wavelength
range by SUMER on SOHO led to the discovery of unusual emission
features - called humps here - at 116.70 nm and 117.05 nm on either
side of the He i 58.43 nm line. This resonance line is seen in the
second order of diffraction, whereas the humps are recorded in the
first order with the SUMER spectrometer. In its spectra both orders
are superimposed. Two less pronounced humps can be detected at 117.27
nm and near 117.85 nm. After rejecting various possibilities of an
instrumental cause of the humps, they are studied in different solar
regions. Most of the measurements, in particular those related to the
limb-brightening characteristics, indicate that the humps are not part
of the background continuum. An assembly of spectrally-unresolved atomic
or ionic emission lines might be contributing to the hump at 117.05
nm, but no such lines are known near 116.7 nm. It is concluded that we
detect genuine radiation, the generation of which is not understood. A
two-photon emission process, parametric frequency down conversion,
and molecular emissions are briefly considered as causes of the humps,
but a final conclusion could not be reached.

---------------------------------------------------------
Title: The correlation between coronal Doppler shifts and the
supergranular network
Authors: Aiouaz, T.; Peter, H.; Lemaire, P.
2005A&A...435..713A Altcode:
We examine properties of line profiles as found with large raster
scans of the solar corona acquired by the UV spectrometer SUMER on
board SOHO. The observed regions include an equatorial coronal hole,
a polar coronal hole, as well as surrounding quiet Sun areas. In
order to reveal the network and remove strong local brightenings,
a filter is applied to a continuum image. The filtered continuum
image, the intensity image and the dopplergram are used to produce
“scatter diagrams” (dispersion plots). We find correlations
between the chromospheric network, the Ne VIII (770 Å) intensity
and the Ne VIII (770 Å) Doppler shift in quiet Sun areas and in
coronal holes. We establish that the maximum outflow (blue-shift) at
low corona temperatures does not appear in the centre of the network
but rather near network boundaries. Furthermore the maximum blue-shift
seems to appear in the dark regions in Ne VIII line intensity, which
is in agreement with Wilhelm (2000). The opposite correlation appears
for very low intensities (less than half of the average intensity),
revealing in these regions a lack of energy to either accelerate the
solar wind or produce any detectable radiation. The absence of magnetic
field concentration in these regions in a reconstructed magnetogram
from a MDI/SOHO series seems to confirm the lack of energy.

---------------------------------------------------------
Title: EUV imaging spectrometer for the Solar Orbiter mission
Authors: Millard, A. A.; Lemaire, P.; Vial, J. -C.
2005AdSpR..36.1411M Altcode:
The results from missions such as Yohkoh, Trace or SOHO have advanced
our understanding of the solar corona and heliosphere, but also have
raised many new questions. Measurements at higher spatial resolution
and cadence are needed, some regions such as the solar poles or
the inner heliosphere remain unexplored. The Solar Orbiter mission
addresses those questions. UV imaging spectrometers may be included
in the remote sensing instruments package for this mission. Fourier
transform spectrometry (FTS) is an ideal solution for imaging systems
as there is no need to scan the region of interest with a slit to
get a 2D map, and the spectral range covered is only limited by the
bandpass of the filter and the maximum optical path difference that
can be obtained. FTS systems also allow to make observations at high
cadence (100 Hz). Working in the far UV (below 200 nm) requires the use
of reflective only optical systems. A solution for such an instrument
has been designed at IAS and a mock-up has been built in order to test
and validate the working principle. The first results of the alignment
phase are shown.

---------------------------------------------------------
Title: Variation of the full Sun hydrogen Lyman profiles through
solar cycle 23
Authors: Lemaire, P.; Emerich, C.; Vial, J. -C.; Curdt, W.; Schühle,
U.; Wilhelm, K.
2005AdSpR..35..384L Altcode:
The hydrogen Lyman (Lyα, 121.267 nm and Lyβ, 102.572 nm) lines are
important contributors to the solar extreme ultra violet (EUV) flux
which illuminates the upper Earth’s atmosphere. From high resolution
spectral observations performed with the solar ultraviolet measurement
of emitted radiations (SUMER) spectrometer on the Solar and Heliospheric
Observatory (SOHO), the detailed profiles of these two lines have been
obtained. Some insights into the variation of the shape of the profiles,
sampled throughout the present solar cycle 23, are given and discussed.

---------------------------------------------------------
Title: On the Outflow at Solar Corona Heights
Authors: Aiouaz, T.; Peter, H.; Lemaire, P.
2004ESASP.575..331A Altcode: 2004soho...15..331A
No abstract at ADS

---------------------------------------------------------
Title: Imagerie et spectrométrie dans l'UV pour les missions
spatiales solaires LYOT et Solar Orbiter
Authors: Millard, A.; Lemaire, P.; Vial, J. -C.
2004JPhy4.119..235M Altcode:
A l'horizon 2010, les missions spatiales solaires LYOT et Solar Orbiter
permettront d'effectuer des observations du soleil (disque et couronne)
dans l'UV à des résolutions spatiale et temporelle jamais réalisées
auparavant. Pour atteindre ce but, les deux missions utiliseront en
particulier des spectro-imageurs. La longueur d'onde de travail impose
un schéma optique original uniquement en réflexion et utilisant des
réseaux de diffraction. Le concept d'un tel instrument est décrit ici,
et l'avancement de la maquette réalisée à l'IAS sont présentés.

---------------------------------------------------------
Title: Mosaiced and high line frequency VPH gratings for astronomy
Authors: Blanche, Pierre-Alexandre; Gailly, Patrick; Habraken, Serge;
Lemaire, Philippe; Jamar, Claude
2004SPIE.5494..208B Altcode:
To increase the size of the volume phase holographic gratings the
Centre Spatial de Liege can produce, mosaic technic has been tested and
characterized. This method consists of assembling VPH gratings recorded
and processed independently into one larger grating. By this way, the
final grating size becomes virtually unlimited and dispersive elements
can accommodate the largest telescope beams. The second research
line about VPH gratings was the high line frequency domain: ν &gt;
3000 lp/mm. Actually, for these frequencies, diffraction according
to TE and TM modes is maximum for different wavelengths. However,
it is possible to tune the index modulation to three times what is
usually required to use the first diffraction TE peak. In this case,
the second TE maximum matches the first TM maximum and unpolarized
light is so entirely diffracted. This article also summarizes our
prospects in the field of very high index modulation gratings where
Δn as high as 0.14 has been reached; cryogenic temperature operation
for which we have demonstrated our VPH gratings stand -180°C without
any Blaze modification; and wavefront correction by post-polishing
to minimize diffracted beam aberrations. With this latter technique,
λ/6 wavefront over 10 cm diameter has been obtained in the first trial.

---------------------------------------------------------
Title: Development of optical ground verification method for μm to
sub-mm reflectors
Authors: Stockman, Y.; Thizy, C.; Lemaire, P.; Georges, M.; Mazy,
E.; Mazzoli, A.; Houbrechts, Y.; Rochus, P.; Roose, S.; Doyle, D.;
Ulbrich, G.
2004ESASP.554..721S Altcode: 2004icso.conf..721S
Large reflectors and antennas for the IR to mm wavelength range
are being planned for many Earth observation and astronomical
space missions and for commercial communication satellites as
well. Scientific observatories require large telescopes with precisely
shaped reflectors for collecting the electro-magnetic radiation from
faint sources. The challenging tasks of on-ground testing are to
achieve the required accuracy in the measurement of the reflector
shapes and antenna structures and to verify their performance under
simulated space conditions (vacuum, low temperatures). Due to the
specific surface characteristics of reflectors operating in these
spectral regions, standard optical metrology methods employed in
the visible spectrum do not provide useful measurement results. The
current state-of-the-art commercial metrology systems are not able
to measure these types of reflectors because they have to face the
measurement of shape and waviness over relatively large areas with a
large deformation dynamic range and encompassing a wide range of spatial
frequencies. 3-D metrology (tactile coordinate measurement) machines
are generally used during the manufacturing process. Unfortunately,
these instruments cannot be used in the operational environmental
conditions of the reflector. The application of standard visible
wavelength interferometric methods is very limited or impossible due
to the large relative surface roughnesses involved. A small number
of infrared interferometers have been commercially developed over
the last 10 years but their applications have also been limited
due to poor dynamic range and the restricted spatial resolution of
their detectors. These restrictions affect also the surface error
slopes that can be captured and makes their application to surfaces
manufactured using CRFP honeycomb technologies rather difficult
or impossible. It has therefore been considered essential, from the
viewpoint of supporting future ESA exploration missions, to develop and
realise suitable verification tools based on infrared interferometry
and other optical techniques for testing large reflector structures,
telescope configurations and their performances under simulated space
conditions. The first one is an IR-phase shifting interferometer
with high spatial resolution. This interferometer shall be used
specifically for the verification of high precision IR, FIR and sub-mm
reflector surfaces and telescopes under both ambient and thermal vacuum
conditions. The second one presented hereafter is a holographic method
for relative shape measurement. The holographic solution proposed makes
use of a home built vacuum compatible holographic camera that allows
displacement measurements from typically 20 nanometres to 25 microns
in one shot. An iterative process allows the measurement of a total
of up to several mm of deformation. Uniquely the system is designed
to measure both specular and diffuse surfaces.

---------------------------------------------------------
Title: EUV imager and spectrometer for Lyot and Solar Orbiter space
missions
Authors: Millard, Anne; Lemaire, Philippe; Vial, Jean-Claude
2004ESASP.554..351M Altcode: 2004icso.conf..351M
In the 2010 horizon, solar space missions such as LYOT and Solar
Orbiter will allow high cadence UV observations of the Sun at spatial
and spectral resolution never obtained before. To reach these goals,
the two missions could take advantage of spectro-imagers. A reflective
only optical solution for such an instrument is described in this
paper and the first results of the mock-up being built at IAS are shown.

---------------------------------------------------------
Title: A New Relation between Central and Total Solar H I Lyman-α
Irradiances, as measured by SOHO during Solar Cycle 23 (1996-2003)
Authors: Emerich, C.; Lemaire, P.; Vial, J. -C.; Curdt, W.; Schüle,
U.; Wilhelm, K.
2004AAS...204.9802E Altcode: 2004BAAS...36..984E
The spectral irradiance at the center of the solar H Ly-α line profile
is the main excitation source responsible for the atomic hydrogen
resonant scattering in cool material. It has therefore to be known
with the best possible accuracy to model the H Ly-α emissions taking
place in planetary, cometary and interplanetary environments. On
the other hand, the only permanently monitored solar irradiance is
the total one - either measured by near-Earth satellites, or deduced
from its correlation with solar activity indexes. It is the reason why
Vidal-Madjar (1975) using OSO-5 satellite H Ly-α data, established a
semi-empirical formula allowing to deduce the central H Ly-α irradiance
from the integrated one. This relation has been extensively used for
three decades. In fact, at the low altitude of the OSO-5 orbit, the
observed central part of the solar line profiles was deeply absorbed by
a large column of exospheric atomic hydrogen. Consequently, the solar
line center irradiances were not measured directly, but obtained by
confronting the measurements with simulations of both the geocoronal
absorption and the self-reversed shape of the central solar profile
itself. On the contrary, the SOHO/SUMER spectrometer orbiting well
outside the H geocoronal envelope (at the L1 Sun-Earth Lagrange point),
provided full Sun H Ly-α profiles, exempt from any central geocoronal
absorption (Lemaire et al. (1998, 2002, 2004)). This has made it
possible to directly measure the central H Ly-α solar irradiances
as a function of the integrated ones, during eight years of Solar
Cycle 23. The newly obtained relation confirms the general trend of
the previous one, but it is characterized by significantly different
coefficients. It will therefore provide new and more accurate inputs
for the future modeling of the various Ly-α emissions occurring inside
the Solar System.

---------------------------------------------------------
Title: Flare observation of the Sun as a star by SUMER/SOHO in the
hydrogen Lyman continuum
Authors: Lemaire, P.; Gouttebroze, P.; Vial, J. -C.; Curdt, W.;
Schühle, U.; Wilhelm, K.
2004A&A...418..737L Altcode:
During the execution of the programme “Sun as a star”, while the
SUMER (Solar Ultraviolet Emission of Emitted Radiation)/SOHO (SOlar and
Heliospheric Observatory) slit was collecting the scattered radiation
from the telescope mirror far away from the solar disk image, a class
X5.3/3b flare erupted on the solar disk, on 25 August 2001. During
the first phase of the flare a relative increase of a few percent was
detected at the head of the hydrogen Lyman continuum. After correction
from the instrumental parameters, the relative signal increase is 70%
at the head of the Lyman continuum (910 Å), and 190% in the C II 904
Å multiplet. Accounting for the area of the flare region, the local
increase of the radiance of the Lyman continuum and of the C II lines
is estimated to be a factor of several thousands. We compare this
result with other solar observations and models. Appendix A is
only available in electronic form at http://www.edpsciences.org

---------------------------------------------------------
Title: Prominence atlas in the SUMER range 800 1250 Å:
I. Observations, data reduction and preliminary results
Authors: Parenti, S.; Vial, J. -C.; Lemaire, P.
2004SoPh..220...61P Altcode:
The aim of this work is to build an EUV-UV spectral catalogue of a
prominence. Here we focus on the preparatory work for the final result
and we give an example of the results obtained. As a first step, we
present the information needed for a full understanding of the results
that will form the final entire catalogue. The data are composed of a
full SUMER spectrum in the range 800-1250 Å of a prominence observed
on 8 October 1999. A quiet-Sun area was also observed in the same
spectral range in order to have a reference spectrum. Beside the
standard corrections, we give details of the estimated stray light
and the wavelength calibration of both datasets. We also present a
short list of lines as an example of the results from the line-fitting
procedure we applied to the data. For each line we give the measured
position, the total intensity and the FWHM in the quiet Sun and at two
different spatial positions in the prominence. With a final atlas of
the prominence it will be possible to investigate several properties
of the feature such as mass motion, differential emission measure,
density, and elemental composition.

---------------------------------------------------------
Title: Development of imaging arrays for solar UV observations based
on wide band gap materials
Authors: Schuehle, Udo H.; Hochedez, Jean-Francois E.; Pau, Jose Luis;
Rivera, Carlos; Munoz, Elias; Alvarez, Jose; Kleider, Jean-Paul;
Lemaire, Philippe; Appourchaux, Thierry; Fleck, Bernhard; Peacock,
Anthony; Richter, Mathias; Kroth, Udo; Gottwald, Alexander; Castex,
Marie-Claude; Deneuville, Alain; Muret, Pierre; Nesladek, Milos;
Omnes, Franck; John, Joachim; Van Hoof, Chris
2004SPIE.5171..231S Altcode:
Solar ultraviolet imaging instruments in space pose most demanding
requirements on their detectors in terms of dynamic range, low noise,
high speed, and high resolution. Yet UV detectors used on missions
presently in space have major drawbacks limiting their performance
and stability. In view of future solar space missions we have started
the development of new imaging array devices based on wide band gap
materials (WBGM), for which the expected benefits of the new sensors -
primarily visible blindness and radiation hardness - will be highly
valuable. Within this initiative, called "Blind to Optical Light
Detectors (BOLD)", we have investigated devices made of AlGa-nitrides
and diamond. We present results of the responsivity measurements
extending from the visible down to extreme UV wavelengths. We discuss
the possible benefits of these new devices and point out ways to build
new imaging arrays for future space missions.

---------------------------------------------------------
Title: Outflow Velocities in Polar Coronal Holes
Authors: Gabriel, A. H.; Bely-Dubau, F.; Lemaire, P.; Antonucci, E.
2004IAUS..219..635G Altcode: 2003IAUS..219E.100G
It is well established that the fast solar wind originates during
the solar minimum from the polar coronal holes. The object is to
investigate this wind onset region to identify the solar structures
responsible. We report here the first measurements of outflow velocities
between 1.0 and 1.3 Ro in solar plumes using XUV spectral lines from
SUMER/SOHO and the Doppler dimming technique. In contrast to what has
been suggested by several other observers using SOHO data we conclude
that the wind velocity in plumes is greater than in the interplume
regions. This tendency diminishes with height so that it may vanish
or even reverse at greater distances. We show that one half of the
solar wind observed at 1 A.U. from Ulysses originates from the solar
plumes at 1.1 Ro. We are extending these observations to 4 Ro using the
UVCS/SOHO spectro-coronagraph to understand the connection with plumes
seen at greater distances. Initial indications suggest a change in the
physical nature of plumes around 2.0 Ro raising questions concerning
their relation to the frequently seen white-light plumes at large
distances. We explore the possible connection between polar plumes
the supergranule network and coronal heating in non-hole regions.

---------------------------------------------------------
Title: A Search for Signatures of Preferential Heating by Ion
Cyclotron Waves in the Low Corona
Authors: Dolla, L.; Solomon, J.; Lemaire, P.
2004ESASP.547..391D Altcode: 2004soho...13..391D
Pointing above the solar Poles (above the limb), in May 2002 (MEDOC
Campaign #9), with the SUMER spectrometer (on board SOHO), we measure
the width of several minor ion lines. Assuming the same so-called
"unresolved velocity" for each ion, we derive the temperature
of the ion species. We then investigate the possible presence of
preferential heating of ions presenting a low charge-to-mass ratio,
characteristic of ion cyclotron interaction. For a given altitude,
the trend of the temperature as a function of the charge-to-mass
ratio is difficult to interpret, due to the unknown value of . We
get rid of that constraint by analysing the difference of line width
with the altitude. Interpreted in terms of difference in temperature
only, it is independent of the absolute value of the temperature,
or of the unresolved velocity. Nevertheless, one could interpret,
to a certain extent, the difference in line width as an increase of
the unresolved velocity with altitude. We conclude that our results
support the possibility of a preferential ion cyclotron heating.

---------------------------------------------------------
Title: Quiet sun xuv and euv spectroscopy
Authors: Lemaire, P.
2004cosp...35.4447L Altcode: 2004cosp.meet.4447L
The two XUV - EUV spectrometers on SOHO have collected a large amount of
data in the 6000 K - 1.E6 K solar plasma temperature range. These data
have allowed to greatly enhance our knowledge of the processes acting in
the solar atmosphere, from the chromosphere to the corona. Some results
on the quiet Sun structure (network, quiet Sun versus coronal hole),
on the dynamics (velocities, waves, transient events), and the main
characteristics of the quiet Sun atmosphere are presented and discussed.

---------------------------------------------------------
Title: Variation of the full Sun hydrogen Lyman profiles through
solar cycle 23
Authors: Lemaire, P.; Emerich, C.; Vial, J. -C.; Curdt, W.; Schühle,
U.; Wilhelm, K.
2004cosp...35..510L Altcode: 2004cosp.meet..510L
The hydrogen Lyman (121.267 nm and 102.572 nm) lines are important
contributors to the solar EUV flux which illuminates the upper Earth's
atmosphere. From high resolution spectral observations performed with
the SUMER FUV-EUV spectrometer on SoHO, the detailed profiles of these
two lines have been obtained. Some insights into the variation of the
shape of the profiles, sampled throughout the present solar cycle 23,
are shown and discussed.

---------------------------------------------------------
Title: UV imager and spectrometer for LYOT and Solar Orbiter space
missions
Authors: Millard, A.; Lemaire, P.; Vial, J. -C.
2004cosp...35.1749M Altcode: 2004cosp.meet.1749M
The results from missions such as Yohkoh, Trace or SOHO have advanced
our understanding of the solar corona and heliosphere, but also have
raised many new questions. Measurements at higher spatial resolution and
cadence are needed, some regions such as the solar poles or the inner
heliosphere remain unexplored. Both LYOT and Solar Orbiter mission
address those questions. UV imaging spectrometers may be included in
the remote sensing instruments packages for these missions. Fourier
transform spectrometry (FTS) is an ideal solution for imaging systems
as there is no need to scan the region of interest with a slit to
get a 2D map, and the spectral ranged covered is only limited by the
bandpass of the filter and the maximum optical path difference that
can be obtained. FTS systems also allows to make observations at high
cadence (100 Hz). Working in the far UV (below 200 nm) requires the use
of reflective only optical systems. A solution for such an instrument
has been designed at IAS and a mock-up has been built in order to test
and validate the working principle. The first results of the alignment
phase are shown.

---------------------------------------------------------
Title: Dynamics and Properties of Coronal Funnels
Authors: Aiouaz, T.; Peter, H.; Lemaire, P.; Keppens, R.
2004ESASP.547..375A Altcode: 2004soho...13..375A
Coronal funnels are open magnetic structures connecting the chromosphere
with the solar corona [5, 3]. We investigate the stationary plasma
flow out of funnels with a 2D- MHD model. The funnel area function is
derived from a magnetic field model and the funnel is approximately 10
Mm high and 20 Mm wide. The energy balance includes radiative losses,
thermal conduction, and a parametrized heating function. We adjust the
parameters to the quantities measured in the lower solar corona. We
obtained 2D plasma properties (e.g. density, temperature, flow speed,
etc.) within the funnel. From the results of the MHD calculation we
synthesize emision profiles of various lines formed in the transition
region from the chromosphere to the corona. This allows us to study
e.g. the Doppler shifts at various temperatures across the funnel
and thus enables a detailed comparison of the model results with
observations. For this we investigate SUMER data and study Doppler
shifts perpendicular to the chromospheric network for different emission
lines, where a tessalation technique is used to derive the outlines of
the chromospheric network. In this paper typical results are presented
for the Ne VIII(770.4 Å) line. Preliminary results show that these
model caclulations compare well to the observations.

---------------------------------------------------------
Title: Is there ion cyclotron preferential heating in the low solar
corona ?
Authors: Dolla, L.; Solomon, J.; Lemaire, P.
2004cosp...35.2315D Altcode: 2004cosp.meet.2315D
The profile of optically thin lines in the solar corona is the
reflection of the kinetic distribution of the emitting ion species,
integrated over the solid angle of the observation. Then, the
line width can be interpreted as the sum of two contributions :
the thermal broadening of the kinetic distribution of each single
elementary volume, and an additional non-thermal broadening due to
the dispersion of fluid velocities of all the elementary volumes,
at scales smaller than the spatial resolution of the instrument, and
along the line of sight (fluid motion due to, e.g., Alfvén waves
or turbulence). We report measurements of EUV coronal line widths,
with SoHO/SUMER, between 1 and 1.2 solar radii above polar coronal
holes. We investigate the presence of preferential heating of ions
with the lowest charge-to-mass ratios, that could be induced by ion
cyclotron waves. To distinguish between the thermal and non-thermal
contributions to the line width, and correctly interpret its radial
variation with altitude, one would need, in principle, both ions with
low and with heavy masses for each charge-to-mass ratio (or at least the
same mass for each charge-to-mass ratio). This is not the case with the
ions emitting in the SUMER spectral range : low charge-to-mass ratios
are highly correlated with heavy masses. Nevertheless, we note some
trend towards ion cyclotron preferential heating, although the data
are also compatible with a common increase of the non-thermal velocity
for all ions. In this work, we pay careful attention to the problem of
instrumental stray light, by correcting the observed line profiles by
a predicted stray light profile, when a coronal line is blended with a
“cold” line seen as stray light.

---------------------------------------------------------
Title: Statistical Study of SOHO/SUMER Full-Sun Images
Authors: Buchlin, E.; Vial, J. -C.; Lemaire, P.; Galtier, S.
2004ESASP.547..337B Altcode: 2004soho...13..337B
A series of full-Sun observations was performed with the SoHO/SUMER
instrument between March and October 1996. Some moments of the
S VI 93.3nm, S VI 94.4nm, and Ly line profiles were computed
on-board. Intensities and line-of-sight velocities in a large central
region of the Sun are studied statistically: histograms of intensities
are computed, as well as histograms of total intensities of "events",
and structure functions of the intensity field. Some statistics of
velocities are the first to be obtained from observational data. The
aim is to compare these statistics to results previously obtained with
SoHO/EIT and by numerical simulations of MHD. Signatures of turbulent
intermittency are also researched.

---------------------------------------------------------
Title: Statistical properties of turbulence and intermittency in
the solar corona observed in EUV
Authors: Buchlin, E.; Vial, J. -C.; Lemaire, P.
2004cosp...35.3556B Altcode: 2004cosp.meet.3556B
Statistical properties of the fields observed on the Sun in EUV may
help to understand turbulence in the solar corona and give clues to
the processes involved in the heating of the corona to millions of
degrees. In this study, we use a series of full-Sun images obtained
in 1996 by the SUMER spectroheliograph on SoHO. Each observation
consists of eight limb-to-limb raster scans in the lines Ly ɛ, S VI
193.3 nm, and S VI 194.4 nm. Intensities, Doppler velocity shifts and
line widths were computed on-board. A context spectrum was measured
for each observation. Intensities and line-of-sight velocities data
in a large central region of the Sun are then studied statistically:
histograms of data values and of events, structure functions, and
other statistics are computed. They are compared to results obtained
by imaging instruments like SoHO/EIT and to numerical simulations of
MHD. Structure functions of the velocity field reveal that turbulence
in the corona may be intermittent.

---------------------------------------------------------
Title: A search for turbulent wave heating and acceleration signatures
with SOHO/SUMER observations : Measurements of the widths of off-limb
Iron lines
Authors: Dolla, L.; Lemaire, P.; Solomon, J.; Vial, J. -C.
2003AIPC..679..351D Altcode:
The widths of coronal ions lines may contain important information
about the energetics of the solar wind and corona. We present a
method to measure these widths, taking into account the problems of
instrumental stray light inherent to SoHO/SUMER. The Iron lines are
interesting to set an upper limit on the “unresolved” velocity,
that may be a signature of turbulent or wave motion in the corona.

---------------------------------------------------------
Title: Dynamics and Properties of Coronal Funnels
Authors: Aiouaz, T.; Peter, H.; Lemaire, Philippe; Keppens, Rony
2003ANS...324....7A Altcode: 2003ANS...324..B01A
No abstract at ADS

---------------------------------------------------------
Title: Images of the solar upper atmosphere from SUMER on SOHO
Authors: Feldman, Uri; Dammasch, Ingolf E.; Wilhelm, Klaus; Lemaire,
Philippe; Hassler, Donald M.; Battrick, Bruce
2003ESASP1274.....F Altcode: 2003isua.book.....F
During the first year of SOHO operations and later in 1999, SUMER
acquired several thousand images of the solar upper atmosphere. This
atlas includes most of the full-Sun images that SUMER recorded
and the majority of its images acquired during the Whole-Sun Month
campaign. One of our main tasks while selecting the atlas format has
been the implementation of our desire to maintain the high spatial
resolution that SUMER achieved. In particular we hope that people
with average vision will be able to see the finest details of the
plasma structures that SUMER can resolve. Thus the page size has
been chosen such that the finest resolution element in the images
corresponds to approximately 250 μm in this atlas. The images in
the atlas were recorded in spectral lines or in continuum radiation
emitted by plasmas spanning the electron temperature domain from
1×104K to 1.4×106K. Some of the images were
recorded simultaneously in radiation emitted by plasmas of different
temperatures. Due to substantial differences of the plasma properties
from which the radiation originated, the atlas provides a unique source
for studying many aspects of the solar upper atmosphere.

---------------------------------------------------------
Title: The Contribution of Polar Plumes to the Fast Solar Wind
Authors: Gabriel, A. H.; Bely-Dubau, F.; Lemaire, P.
2003ApJ...589..623G Altcode:
The Doppler dimming technique is used for the first time to
study ultraviolet polar plumes in the height range of 1.05-1.35
Rsolar, using observations from the spectrometer SUMER on
the Solar and Heliospheric Observatory. It is found that, contrary to
a number of published suggestions, outflow velocities in the plumes
exceed those in the interplume regions. Plume velocities are in excess
of 60 km s-1 and are approximately constant throughout
this height region. They tend to converge with the velocity of the
accelerating interplume material at some height above our region of
study. The analysis suggests that plume material makes a substantial
contribution to the total line of sight, favoring either a “curtain”
model for plumes or a chance alignment of a number of elementary
cylindrical plumes. The intrinsic local density of plume material is
some 20%-50% in excess of the interplume regions. Estimation of the
total mass outflow indicates that approximately half of the fast solar
wind at 1.1 Rsolar arises from plumes, with the remainder
from interplume material. This result validates the published electron
temperature profile of David et al. for the fast wind onset, which
had been questioned over the suggestion that the flow velocity might
be negligible in solar plumes.

---------------------------------------------------------
Title: The solar high-resolution imager - coronagraph LYOT mission
Authors: Vial, Jean-Claude; Song, Xueyan; Lemaire, Philippe; Gabriel,
Alan H.; Delaboudiniere, Jean-Pierre; Bocchialini, Karine; Koutchmy,
Serge L.; Lamy, Philippe L.; Mercier, Raymond; Ravet, Marie Francoise;
Auchere, Frederic
2003SPIE.4853..479V Altcode:
The LYOT (LYman Orbiting Telescope) solar mission is proposed to
be implemented on a micro-satellite of CNES (France) under phase A
study. It includes two main instruments, which image the solar disk
and the low corona up to 2.5 Ro in the H I Lyman-α line
at 121.6 nm. The spatial resolution is about 1” for the disk and
2.5” for corona. It also carries an EIT-type telescope in the He II
(30.4 nm) line. The coronagraph needs a super polished mirror at the
entrance pupil to minimize the light scattering. Gratings and optical
filters are used to select the Lyman-α wavelength. VUV cameras with
2048×2048 pixels record solar images up to every 10 seconds. The
satellite operates at a high telemetry rate (more then 100 kb/s,
after onboard data compression). The envisaged orbits are either
geostationary or heliosynchronous. Possible launch dates could be end
of 2006 - beginning of 2007.

---------------------------------------------------------
Title: New UV detectors for solar observations
Authors: Hochedez, Jean-Francois E.; Schuehle, Udo H.; Pau, Jose L.;
Alvarez, Jose; Hainaut, Olivier; Appourchaux, Thierry P.; Auret, F. D.;
Belsky, Andrei; Bergonzo, Philippe; Castex, M. C.; Deneuville, A.;
Dhez, Pierre; Fleck, Bernhard; Haenen, Ken; Idir, Mourad; Kleider,
Jean Paul; Lefeuvre, Elie; Lemaire, Philippe; Monroy, E.; Muret, P.;
Munoz, Elias; Nesladek, Milos; Omnes, Franck; Pace, Emanuele; Peacock,
Anthony J.; Van Hoof, Chris A.
2003SPIE.4853..419H Altcode:
BOLD (Blind to the Optical Light Detectors) is an international
initiative dedicated to the development of novel imaging detectors
for UV solar observations. It relies on the properties of wide bandgap
materials (in particular diamond and Al-Ga-nitrides). The investigation
is proposed in view of the Solar Orbiter (S.O.) UV instruments, for
which the expected benefits of the new sensors -primarily visible
blindness and radiation hardness- will be highly valuable. Despite
various advances in the technology of imaging detectors over the last
decades, the present UV imagers based on silicon CCDs or microchannel
plates exhibit limitations inherent to their actual material
and technology. Yet, the utmost spatial resolution, fast temporal
cadence, sensitivity, and photometric accuracy will be decisive for
the forthcoming solar space missions. The advent of imagers based on
wide-bandgap materials will permit new observations and, by simplifying
their design, cheaper instruments. As for the Solar Orbiter, the
aspiration for wide-bandgap material (WBGM) based UV detectors is still
more sensible because the spacecraft will approach the Sun where the
heat and the radiation fluxes are high. We describe the motivations,
and present the program to achieve revolutionary flight cameras within
the Solar Orbiter schedule as well as relevant UV measurements.

---------------------------------------------------------
Title: Large-scale DCG transmission holographic gratings for astronomy
Authors: Blanche, Pierre-Alexandre; Habraken, Serge L.; Lemaire,
Philippe C.; Jamar, Claude A. J.
2003SPIE.4842...31B Altcode:
The recent interest of the astronomer community for volume phase
holographic gratings is directly related to the enhancement of
spectrograph throughput since this kind of grating can rise higher
diffraction efficiency. Indeed, dichromated gelatine technology has
demonstrated capability for 70-90% efficiency. From the heritage
of several diffractive and holographic projects and applications,
the Centre Spatial de Liege has recently decided to invest in the
large-scale DCG grating technology. This paper will present the new
facility which is now fully operational, its capability and first
results obtained.

---------------------------------------------------------
Title: Linear polarization of the O VI lambda 1031.92 coronal
line. II. Constraints on the magnetic field and the solar wind
velocity field vectors in the coronal polar holes
Authors: Raouafi, N. -E.; Sahal-Bréchot, S.; Lemaire, P.
2002A&A...396.1019R Altcode:
Numerical computation results of the linear polarization parameters
of the O VI lambda1031 .92 coronal line are presented. They are
based on theoretical results obtained by Raouafi (2002 and 2000),
which give the Stokes parameters of a resonance scattering spectral
line sensitive simultaneously to the Hanle effect and to the Doppler
redistribution. In the present coronal case, the Hanle effect is
due to the coronal magnetic field and the Doppler redistribution
to the macroscopic motion of the scattering O5+ coronal
ions (solar wind velocity field vector). Constraints on the coronal
magnetic field vector and on the solar wind velocity field vector are
obtained by comparing the numerical results and the linear polarization
measurements of the O VI lambda1031 .92 coronal line obtained through
particular observations performed by SUMER/SoHO.

---------------------------------------------------------
Title: Quiet-Sun chromospheric network evolution
Authors: Lemaire, Philippe; Vial, J. -C.; Curdt, W.; Schühle, U.;
Wilhelm, K.
2002ESASP.505..477L Altcode: 2002solm.conf..477L; 2002IAUCo.188..477L
Using the SUMER/SOHO spectrometer we have observed the same quiet-Sun
area during several days in a set of eight spectral lines of the
transition region. Line intensity maps of the rastered areas are used to
separate the interior of the supergranular cells from the network. Then,
following the evolution of the supergranular pattern, we measure the
variations of intensity and the Doppler shifts at several temperatures
of formation of the transition region. We find that the overall flow
velocity of the cell interior and the network generally decays within
ten hours, which represents a significant part of the supergranular
lifetime.

---------------------------------------------------------
Title: From chromosphere to corona through ground-based to space
observatories
Authors: Lemaire, P.
2002NCimC..25..719L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Linear polarization of the O VI lambda 1031.92 coronal
line. I. Constraints on the solar wind velocity field vector in the
polar holes
Authors: Raouafi, N. -E.; Sahal-Bréchot, S.; Lemaire, P.; Bommier, V.
2002A&A...390..691R Altcode:
In the first part of the present work, we report on the determination
of the linear polarization parameters of the O VI lambda1031 .92
coronal line (hereafter O VI D2). Spectropolarimetric
observations done by the SUMER spectrometer on board the spacecraft
SoHO during minimum activity of the solar cycle (March, 1996) in the
south coronal hole were used to analyze the partial linear polarization
of the D2 resonance line scattered by the O {VI} coronal
ions. Widths of the O VI D2 and O VI 1037.61 (hereafter
O VI D1) lines and limb-brightening determined from data
observations of SUMER/SoHO are also presented. The second part of this
work is devoted to the interpretation of the determined polarization
parameters in terms of the macroscopic velocity field vector of the
O VI coronal ions that can be assimilated to the solar wind velocity
field. Numerical results of the linear polarization parameters of
the O VI D2 coronal line are presented. Constraints on the
strength and direction of the solar wind velocity vector are obtained
by comparing the numerical and the observational results of the O VI
D2 coronal line polarization parameters. In conclusion, the
effect of the macroscopic velocity field vector of the scattering ions
(Doppler redistribution) provides a first set of results compatible
with the observations. However, the inclination of the derived set
of compatible field vectors, with respect to the solar vertical, is
higher than expected in a coronal hole. The result will be improved
by the inclusion of the magnetic field effect (Hanle effect), which
will be treated in a further paper.

---------------------------------------------------------
Title: A SUMER spectral atlas for prominences
Authors: Parenti, Susanna; Vial, J. -C.; Lemaire, P.
2002ESASP.508..327P Altcode: 2002soho...11..327P
We present preliminary results of a study aimed at building a SUMER
atlas for prominences. Using the atlas as reference, further studies
can be addressed at deriving prominence properties, such as DEM
distribution and anomalies in element abundances. Moreover, a comparison
with previous atlas (e.g. Curdt et al., 2001) of other solar regions
can be made. An extended prominence was observed with SUMER in the
South-West solar limb in October 1999. A full spectrum was obtained
in the waveband 790 - 1600 Å. After dealing with off-limb scattered
light, the data are processed using multi-Gaussian fitting in order
to derive the spectral properties of the observed structure. These
properties are then also compared with those of the Quiet Sun area
observed in the same wavelength range.

---------------------------------------------------------
Title: Effect of the solar wind velocity field vector on the
polarization of the O VI λ1032 coronal line
Authors: Raouafi, N. -E.; Sahal-Bréchot, S.; Lemaire, P.
2002ESASP.508..471R Altcode: 2002soho...11..471R
The linear polarization parameters of the O VI λ1032 coronal line
(D2 line) are measured by using spectropolarimetric
observations performed by the SUMER spectrometer on board the SoHO
spacecraft during activity minimum of the solar cycle (March, 1996),
in the south coronal hole. The interpretation of the determined
polarization parameters in terms of the macroscopic velocity field
vector of the O VI coronal ions (which can be assimilated to the solar
wind velocity field) gives constraints on the strength and direction
of the solar wind velocity field vector. They are obtained by comparing
the numerical and the observational results of the linear polarization
parameters of the O VI D2 coronal line.

---------------------------------------------------------
Title: Effect of the coronal magnetic field and the solar wind
velocity field vectors on the polarization of the O VI λ1032 line
Authors: Raouafi, N. -E.; Lemaire, P.; Sahal-Bréchot, S.
2002ESASP.508..403R Altcode: 2002soho...11..403R
Numerical computation results of the combination of the Hanle effect
(due to the coronal magnetic field) and to the Doppler redistribution
effect (due to the solar wind velocity field) on the linear polarization
parameters of the O VI λ1032 coronal line (D2 line) are
presented. Constraints on the magnetic field and the solar wind velocity
field vectors are obtained by comparing the present results and the
measurements of the polarization parameters of the O VI D2
coronal line by using SUMER/SoHO polarimetric observations done in the
south coronal polar hole during the minimum of the solar activity cycle.

---------------------------------------------------------
Title: Variation of the full Sun hydrogen Lyman α and β profiles
with the activity cycle
Authors: Lemaire, Philippe; Emerich, C.; Vial, J. -C.; Curdt, W.;
Schühle, U.; Wilhelm, K.
2002ESASP.508..219L Altcode: 2002soho...11..219L
Full Sun hydrogen Lyman α and β profiles obtained through the
activity cycle are needed to compare with stars, to understand the
hydrogen distribution in the heliosphere and to evaluate the processes
in the upper planetary atmospheres. Using the SUMER/SOHO telesocope
scattered light properties, we have measured the Lyman α and β
profiles at different epochs of the solar activity cycle. Here we
report modifications in the intensity and the shape of the profiles.

---------------------------------------------------------
Title: SUMER in retrospective and future EUV spectrometers
Authors: Lemaire, Philippe
2002ESASP.508..539L Altcode: 2002soho...11..539L
The SUMER spectrometer normal incidence design comes from the
improvement of previous designs and the development of new
technologies. A review of some of the historical progresses is
presented. An analysis of the needs for the solar transition and low
coronal physics provides guidelines for future FUV-EUV spectrometers. To
avoid the slit limitation we propose a 2D imaging Fourier transform
spectrometer.

---------------------------------------------------------
Title: Transition region quiet sun velocity field evolution
Authors: Lemaire, P.; Artzner, G.; Vial, J. -C.; Curdt, W.; Schühle,
U.; Wilhelm, K.
2002AdSpR..30..487L Altcode:
The UV/EUV SUMER spectrometer aboard SOHO can record profiles of lines
emitted by elements at different stages of ionization corresponding
to several temperatures within the transition region temperature
range. During the solar cycle minimum in July 1996, we were able to
observe the quiet Sun during five consecutive days. From the line
positions we have determined the velocity fields and follow their time
variations at different temperatures in the transition region. The line
intensity maps are used to separate supergranular cells and network and
they allow to compare the behaviors of the velocity fields evolution in
the two structures. The results are critically analyzed and discussed.

---------------------------------------------------------
Title: Solar Vacuum-ultraviolet Radiometry with SUMER
Authors: Wilhelm, K.; Schuhle, U.; Curdt, W.; Dammasch, I. E.;
Hollandt, J.; Lemaire, P.; Huber, M. C. E.
2002ISSIR...2..145W Altcode: 2002ESASR...2..145W; 2002rcs..conf..145W
Since the beginning of 1996, the space-based telescope and
spectrograph SUMER (Solar Ultraviolet Measurements of Emitted
Radiation) on the SOlar and Heliospheric Observatory (SOHO) of ESA
and NASA has obtained spectra of many features of the quiescent and
active Sun with high spectral and spatial resolution. In addition,
irradiance and radiance measurements of line and continuum emission
have been performed in the wavelength range 46.5 nm to 161.0 nm. The
instrument was radiometrically calibrated against the Berlin Electron
Storage ring for SYnchrotron radiation (BESSY I), a primary source
standard, with the help of a transfer source standard based on a
hollow-cathode discharge lamp. A thorough cleanliness programme,
specifically aimed at chemical contamination control, resulted in an
excellent radiometric stability of the normal-incidence optical system
as well as of the detectors. This has been verified under operational
conditions by various techniques employed during the SOHO mission,
such as line-ratio studies, observations of stars, and comparisons with
other instruments. The observations provide vacuum-ultraviolet (VUV)
radiometry of the Sun in many emission lines and continua of atoms
and ions with relative standard uncertainties of 15 % (detector A)
and 20 % (detector B) for the wavelength range 53 nm to 124 nm, with
larger uncertainties outside this interval and after the SOHO recovery
in 1998. We report on the present state of the SUMER radiometric
calibration and provide a full bibliography related to this topic.

---------------------------------------------------------
Title: SUMER Stellar Observations to Monitor Responsivity Variations
Authors: Lemaire, P.
2002ISSIR...2..265L Altcode: 2002ESASR...2..265L; 2002rcs..conf..265L
Regular observations of α Leo have been performed by SUMER in order to
track responsivity variations in the 95 nm to 160 nm range. Degradation
in responsivity ranging from about 2 % to 5 % at 150 nm and 20 % at
100 nm have been demonstrated for the SUMER optical paths using both A
and B detectors between 1996 and 1999. Later, between 1999 and 2001,
with the optical path using the A detector, the 100 nm responsivity
loss is about 20 %, while that at 150 nm is insignificant.

---------------------------------------------------------
Title: New UV Detector Concepts
Authors: Hochedez, J. -F.; Schuhle, U.; Lemaire, P.
2002ISSIR...2..371H Altcode: 2002rcs..conf..371H; 2002ESASR...2..371H
BOLD (Blind to the Optical Light Detectors) is an international
initiative dedicated to the development of novel imaging detectors
for UV solar observations. It relies on the properties of wide-bandgap
semiconductor materials (in particular diamond and Al-Ganitrides). This
investigation is proposed in view of the Solar Orbiter UV instruments,
for which the expected benefits of the new sensors, visible blindness
and radiation hardness, will be highly valuable. Despite various
advances in the technology of imaging detectors over the last few
decades, the present UV imagers based on silicon CCDs or microchannel
plates exhibit limitations which are inherent to their actual material
and technology. Yet the utmost spatial resolution, fast temporal
cadence, sensitivity, and photometric accuracy will all be decisive for
forthcoming solar space missions. The advent of imagers made of large
wide-bandgap semiconductors would surmount many present weaknesses. This
would open up new scientific prospects and, by simplifying their design,
would even make the instruments cheaper. As for the Solar Orbiter,
the aspiration for wide-bandgap semiconductor-based UV detectors is
still more desirable because the spacecraft will approach the Sun
where heat and radiation fluxes are high. We describe the motivations
leading to such new developments, and present a programme to achieve
revolutionary flight cameras within the Solar Orbiter schedule.

---------------------------------------------------------
Title: JOSO national report 2000-2001 - France
Authors: Schmieder, B.; Mein, P.; Lemaire, P.; Pick, M.; Vilmer, N.
2002joso.book...56S Altcode:
We report on the scientific advances in solar physics in France. The
French Solar community is large split in different laboratories and
observatories. We report on specific groups (THEMIS, SOHO, Nançay).

---------------------------------------------------------
Title: Volume Phase Holographic Gratings Made in Europe
Authors: Habraken, S.; Blanche, P. -A.; Lemaire, P.; Legros, N.;
Dekker, H. .; Monnet, G.
2001Msngr.106....6H Altcode:
This article is a shortened, combined and updated version of papers
given at the August 2001 SPIE conference on Gratings in Astronomy
(Monnet et al., 2001 and Habraken et al., 2001).

---------------------------------------------------------
Title: The SUMER spectral atlas of solar-disk features
Authors: Curdt, W.; Brekke, P.; Feldman, U.; Wilhelm, K.; Dwivedi,
B. N.; Schühle, U.; Lemaire, P.
2001AIPC..598...45C Altcode: 2001sgc..conf...45C
A far-ultraviolet and extreme-ultraviolet (FUV, EUV) spectral atlas
of the Sun between 670 Å and 1609 Å in first order of diffraction
has been derived from observations obtained with the SUMER (Solar
Ultraviolet Measurements of Emitted Radiation) spectrograph on
the spacecraft SOHO (Solar and Heliospheric Observatory) [1]. The
atlas contains spectra of the average quiet Sun, a coronal hole and
a sunspot on disk. Different physical parameters prevalent in the
bright network (BN) and in the cell interior (CI)-contributing in a
distinct manner to the average quiet-Sun emission-have their imprint
on the BN/CI ratio, which is also shown for the entire spectral
range. With a few exceptions, all major lines are given with their
identifications and wavelengths. Lines that appear in second order
are superimposed on the first order spectra, but below 500 Å the
responsivity of the normal-incidence optical system is very low. The
spectra include emissions from atoms and ions in the temperature range
6 103 K to 2 106 K, i.e., continua and mission
lines emitted from the lower chromosphere to the corona. This spectral
atlas, with its broad wavelength coverage, provides a rich source
of new diagnostic tools for studying the physical parameters in the
chromosphere, the transition region and the corona. In particular,
the wavelength range below 1100 Å as observed by SUMER represents
a significant improvement over the spectra produced in the past. In
view of the manifold appearance and temporal variation of the solar
atmosphere it is obvious that our atlas can only be a-hopefully
typical-snapshot. The spectral radiances are determined with a
relative uncertainty of 0.15 to 0.30 (1σ), and the wavelength scale
is accurate to typically 10 mÅ, which is the level achievable with
semi-automatic processing. The SUMER solar-disk spectral atlas will
be published in the near future by Curdt et al. [2]. It includes
profiles of the average quiet Sun, an equatorial coronal hole, and
a sunspot. As an example we show in Fig. 1 the spectral range from
1300 Å to 1342 Å with the prominent O I and C II lines. Resolved
emission lines are indicated by a mark, the measured wavelength in
angstrom, and the identification, if available. Marks point to line
lists available in the literature, where additional information about
a specific line can be found [3-7]. New lines or identifications
are indicated. Lines observed in first order and in second-order of
diffraction are distinguished. Only the three least-significant digits
of the wavelength values are given. If available, unidentified lines
are characterized by the temperature classification defined in [3] (a:
Te&lt;3 105 b: Te~3 105 c:
Te~4 105 d: 6 105&lt;Te
&lt;9 105 e: Te~1.4 106 f:
Te~1.8 106). The vertical axes are scaled
to spectral radiance in units of mW sr-1 m-2
Å-1 on the left the radiometric calibration for first
order lines is given, on the right for second order lines. Note,
that second order lines are always superimposed on a first order
background. We have taken care of the type of photocathode (bare or KBr)
when applying the radiometric calibration to different sections of the
spectrum. Also displayed in green is the BN/CI ratio in an attempt
to characterize the quiet-Sun chromospheric network structure. A
pre-print of the SUMER spectral atlas and a line list is available at
http://www.linmpi.mpg.de/~curdt. .

---------------------------------------------------------
Title: Wide bandgap EUV and VUV imagers for the Solar Orbiter
Authors: Hochedez, Jean-François; Lemaire, Philippe; Pace, Emanuele;
Schühle, Udo; Verwichte, Erwin
2001ESASP.493..245H Altcode: 2001sefs.work..245H
No abstract at ADS

---------------------------------------------------------
Title: VizieR Online Data Catalog: SUMER Spectral Atlas of Solar
Disk Features (Curdt+, 2001)
Authors: Curdt, W.; Brekke, P.; Feldman, U.; Wilhelm, K.; Dwivedi,
B. N.; Schuhle, U.; Lemaire, P.
2001yCat..33750591C Altcode:
List of spectral lines in the wavelength range from 668Å to 1611Å
identified in SUMER (Solar Ultraviolet Measurements of Emitted
Radiation, spectrograph on the spacecraft SOHO) spectra of the average
quiet Sun (QS), a coronal hole (CH) and a sunspot on disk (SS). Spectral
lines observed in second order of diffraction which are also given
here, extend the lower wavelength limit to below 500Å. For each entry
we give the observed wavelengths in angstrom, the identification,
the transition, the peak of spectral radiance, Lpeak, in
mW/(sr*m2*Å) (incl. background), and a cross-reference
to other line lists available in the literature (cf., Sect. 5.1). For
second-order lines radiance entries are generally not provided, since
the background separation in both orders of diffraction is a non-trivial
task, which can not be automated. Only a few radiance values of strong
second-order lines with negligible first-order contribution are given,
which are marked by an asterisk (*). (1 data file).

---------------------------------------------------------
Title: Solar Chromospheric Plage
Authors: Lemaire, P.
2000eaa..bookE2262L Altcode:
Chromospheric plage (from the French 19th century wording: `plage
brillante', bright plage or bright area) or facular plage (facula,
Latin word for small torch) is a bright area seen in chromospheric lines
most of the time surrounding one or several SUNSPOTS. Chromospheric
plage is one of the main components of the solar activity (see SOLAR
ACTIVE REGIONS)....

---------------------------------------------------------
Title: SUMER observations of transition region fine structures
Authors: Landi, E.; Mason, H. E.; Lemaire, P.; Landini, M.
2000A&A...357..743L Altcode:
The SUMER (Solar Ultraviolet Measurements of Emitted Radiation)
instrument on SOHO (Solar and Heliospheric Observatory) provides an
opportunity to observe and study the solar transition region with
high spatial and spectral resolution. We present new evidence to
confirm that the emission from the quiet Sun at 2x 105 K
is dominated by cool loop-like fine structures which cluster across
the chromospheric network boundaries. The electron density of these
structures is found to be around 1010 cm-3. The
red-shifts in spectral line profiles and the non-thermal widths from
lines formed at this temperature are found to be correlated with
intensity. The properties of explosive events with irregular profiles
are explored. A large jet-like structure is analysed. The results of
our analysis are compared with recent predictions from numerical models.

---------------------------------------------------------
Title: Polar Plumes and Inter-plume regions as observed by SUMER
on SOHO
Authors: Banerjee, D.; Teriaca, L.; Doyle, J. G.; Lemaire, P.
2000SoPh..194...43B Altcode:
We present observations of O vi 1032 Å line profiles obtained
with the SUMER instrument on SOHO extending from the solar
disk to 1.5 R⊙ above the limb in the north polar
coronal hole. Variations of the intensity and linewidth in the
polar plume and inter-plume regions are investigated. We find an
anti-correlation between the intensity and the linewidth in the plume
and inter-plume regions with detailed plume structures been seen out
to 1.5 R⊙. Possible implications regarding the magnetic
topologies of these two regions and related heating mechanisms are
discussed. The O vi linewidth measurements are combined with UVCS output
to provide an overview of its variations with height extending up to
3.5 R⊙. We find a linear increase of the linewidth from
1 to 1.2 R⊙, then a plateau followed by a sharp increase
around 1.5 R⊙.

---------------------------------------------------------
Title: Radiance variations of the quiet Sun at far-ultraviolet
wavelengths
Authors: Schühle, U.; Wilhelm, K.; Hollandt, J.; Lemaire, P.;
Pauluhn, A.
2000A&A...354L..71S Altcode:
We have measured the radiance of quiet-Sun areas at the centre of the
solar disk using the vacuum-ultraviolet telescope-spectrograph SUMER
(Solar Ultraviolet Measurements of Emitted Radiation) on the Solar and
Heliospheric Observatory (SOHO). The radiances of selected emission
lines have been measured from March 1996 to the present. The lines that
have been observed regularly since the beginning of the SOHO mission
are He i 584 Å, Mg x 609 Å and 624 Å, Ne viii 770 Å, N v 1238 Å,
and the H i Lyman continuum at 880 Å. We investigate the variability
of these emission lines during the solar minimum and the ascending
phase of the present solar activity cycle. The transition region and
coronal lines show an increasing trend of up to 100% since the sunspot
minimum. The results are important for models of solar VUV variability
on the basis of radiance contrast ratios of solar disk regions. Our
spatially resolved images allow a separation of the network and cell
areas of the quiet-Sun. Both regimes show similar variations.

---------------------------------------------------------
Title: Solar Irradiances of Ultraviolet Emission Lines Measured
During the Minimum of Sunspot Activity in 1996 and 1997
Authors: Wilhelm, K.; Lemaire, P.; Dammasch, I. E.; Hollandt, J.;
Schuhle, U.; Curdt, W.; Kucera, T.; Hassler, D. M.; Humbler, M. C. E.
2000PCEC...25..389W Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Radiometric Calibration of the Vacuum-Ultraviolet Spectrograph
SUMER on the SOHO Spacecraft with the B Detector
Authors: Schühle, Udo; Curdt, Werner; Hollandt, Jörg; Feldman, Uri;
Lemaire, Philippe; Wilhelm, Klaus
2000ApOpt..39..418S Altcode:
The Solar Ultraviolet Measurement of Emitted Radiation (SUMER)
vacuum-ultraviolet spectrograph was calibrated in the laboratory
before the integration of the instrument on the Solar and Heliospheric
Observatory (SOHO) spacecraft in 1995. During the scientific operation
of the SOHO it has been possible to track the radiometric calibration
of the SUMER spectrograph since March 1996 by a strategy that employs
various methods to update the calibration status and improve the
coverage of the spectral calibration curve. The results for the A
Detector were published previously Appl. Opt. 36, 6416 (1997) . During
three years of operation in space, the B detector was used for two
and one-half years. We describe the characteristics of the B detector
and present results of the tracking and refinement of the spectral
calibration curves with it. Observations of the spectra of the stars and
Leonis permit an extrapolation of the calibration curves in the range
from 125 to 149.0 nm. Using a solar coronal spectrum observed above
the solar disk, we can extrapolate the calibration curves by measuring
emission line pairs with well-known intensity ratios. The sensitivity
ratio of the two photocathode areas can be obtained by registration of
many emission lines in the entire spectral range on both KBr-coated and
bare parts of the detector s active surface. The results are found to be
consistent with the published calibration performed in the laboratory
in the wavelength range from 53 to 124 nm. We can extrapolate the
calibration outside this range to 147 nm with a relative uncertainty
of 30% (1 ) for wavelengths longer than 125 nm and to 46.5 nm with 50%
uncertainty for the short-wavelength range below 53 nm.

---------------------------------------------------------
Title: Radiance Variations of Vacuum-Ultraviolet Emission Lines of
the Quiet Sun Observed with SUMER on SOHO
Authors: Schuhle, U.; Pauluhn, A.; Hollandt, J.; Lemaire, P.;
Wilhelm, K.
2000PCEC...25..429S Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Solar spectroradiometry with the telescope and spectrograph
SUMER on the Solar and Heliospheric Observatory SOHO
Authors: Wilhelm, K.; Schühle, U.; Curdt, W.; Dammasch, I. E.;
Hollandt, J.; Lemaire, P.; Huber, M. C. E.
2000Metro..37..393W Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Future Diamond UV Imagers For Solar Physics
Authors: Hochedez, J. -F.; Verwichte, E.; Bergonzo, P.; Guizard, B.;
Mer, C.; Tromson, D.; Sacchi, M.; Dhez, P.; Hainaut, O.; Lemaire,
P.; Vial, J. -C.
2000PSSAR.181..141H Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Observational Signatures of Microscale Heating
Authors: Bocchialini, K.; Aletti, V.; Vial, J. -C.; Lemaire, P.
1999ESASP.448..539B Altcode: 1999ESPM....9..539B; 1999mfsp.conf..539B
No abstract at ADS

---------------------------------------------------------
Title: On VI 1031.95 Å Line Polarization Measurements in View of
Velocity Field and Magnetic Field Diagnostics in the Inner Solar
Corona: Effect of the Polar Hole
Authors: Raouafi, N. -E.; Sahal-Bréchot, S.; Lemaire, P.
1999ESASP.448.1205R Altcode: 1999ESPM....9.1205R; 1999mfsp.conf.1205R
No abstract at ADS

---------------------------------------------------------
Title: The solar ultraviolet spectrum from 1200 Å to 1560 Å:
a radiometric comparison between SUMER/SOHO and SOLSTICE/UARS
Authors: Wilhelm, K.; Woods, T. N.; Schühle, U.; Curdt, W.; Lemaire,
P.; Rottman, G. J.
1999A&A...352..321W Altcode:
After short descriptions of the SUMER (Solar Ultraviolet Measurements
of Emitted Radiation) spectrometer onboard SOHO (the Solar and
Heliospheric Observatory) and the SOLSTICE (Solar-Stellar Irradiance
Comparison Experiment) spectrometer on UARS (the Upper Atmosphere
Research Satellite), a radiometric comparison is carried out of solar
irradiance spectra measured by SOLSTICE and spectra derived from
SUMER radiance observations of quiet-Sun regions in the wavelength
range from 1200 Å to 1560 Å. The emission lines N v (lambda 1238)
and C iv (lambda 1548) are considered in detail. For these lines,
irradiance data are also available from full-Sun raster scans of SUMER
and deviations of less than 15% are found between SOLSTICE and SUMER
results - well within the combined uncertainty margins.

---------------------------------------------------------
Title: Structure and Role of the Transition Region
Authors: Lemaire, P.
1999ESASP.446...35L Altcode: 1999soho....8...35L
No abstract at ADS

---------------------------------------------------------
Title: On VI 103.2 A Line Polarization Measurements In View Of
Velocity Field And Magnetic Field Diagnostics In The Inner Solar
Corona
Authors: Raouafi, N. -E.; Lemaire, P.; Sahal-Bréchot, S.
1999ESASP.446..567R Altcode: 1999soho....8..567R
The linear polarization parameters of the O VI 103.2 nm coronal
line are sensitive to the magnetic field and the solar wind velocity
vector effects (via the Hanle effect and the Doppler dimming effect
respectively). These parameters (degree and direction of linear
polarization) are measured by interpreting observations taken by the
SUMER spectrometer aboard of SOHO. SUMER is sensitive to the linear
polarization state of the observed radiation. The profile and the
shift of the O VI 103.2 nm and 103.7 nm lines and of the other lines
measured during the observations will also be reported. These results
should permit to obtain information on the velocity distribution of
the coronal O VI ions.

---------------------------------------------------------
Title: The Off-Limb Behavior of the First Ionization Potential Effect
in T&gt;5×105 K Solar Plasmas
Authors: Laming, J. M.; Feldman, U.; Drake, J. J.; Lemaire, P.
1999ApJ...518..926L Altcode:
We investigate the behavior of the solar first ionization potential
(FIP) effect (the abundance enhancement of elements with first
ionization potential of less than 10 eV in the corona with respect
to photospheric values) with height above the limb in a region of
diffuse quiet corona observed by the SUMER instrument on SOHO, with
emphasis on so-called upper transition region lines. Previous disk
observations have shown different abundance patterns in emission
from lines at temperatures above and below ~8×105 K,
with an FIP effect clearly visible at the higher temperatures and
less so at the lower temperatures. Our initial aim is to determine
whether such a difference is also visible in off-limb observations. We
find a low-FIP element enhancement of a factor of 3-4 indicated in
all line ratios. The Mg VII 868.11/Ne VII 895.17 ratio is also seen
to decrease toward a photospheric value when tracked down from the
corona to the limb. This is markedly different from the behavior of
higher temperature line ratios and may be related to the differing
heating and mass supply mechanisms for plasmas at temperatures above
and below ~8×105 K. An additional unexpected feature
of our observations is that in low-FIP/high-FIP line ratios formed
at temperatures close to the freeze-in temperature of the fast solar
wind (~106 K), there is also a small diminution of the FIP
enhancement at the highest altitudes observed in this study. We discuss
the possible relevance of this to the origin of the fast solar wind.

---------------------------------------------------------
Title: Detection of the O VI 103.2 NM line polarization by the SUMER
spectrometer on the SOHO spacecraft
Authors: Raouafi, N. -E.; Lemaire, P.; Sahal-Bréchot, S.
1999A&A...345..999R Altcode:
The first detection of the O VI 103.2 nm line polarization has been
performed in the corona by SUMER (Solar Ultraviolet Measurements of
Emitted Radiation) on the SOHO (Solar Heliospheric Observatory). The
polarization properties of the spectrometer was used to analyze
the solar radiation in a coronal hole at about 270 arcsec above the
south solar limb, during the SOHO spacecraft rotation of March 19,
1996. Taking advantage of the different behavior of the lines in the
O VI doublet and of the nearby chromospheric lines we have been able
to extract the weak signal modulation introduced by polarization from
solar variations and telescope scattered light. The ~ 4% modulation
rate (related to the linear polarization of the O VI 103.2 nm line)
derived is an important clue to infer the properties of the local
magnetic field strength and the velocity field in the coronal hole.

---------------------------------------------------------
Title: Solar Wind Outflow and the Chromospheric Magnetic Network
Authors: Hassler, Donald M.; Dammasch, Ingolf E.; Lemaire, Philippe;
Brekke, Pal; Curdt, Werner; Mason, Helen E.; Vial, Jean-Claude;
Wilhelm, Klaus
1999Sci...283..810H Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Oscillations of the upper chromosphere
Authors: Gouttebroze, P.; Vial, J. -C.; Bocchialini, K.; Lemaire,
P.; Leibacher, J. W.
1999SoPh..184..253G Altcode:
Variations of intensity and wavelength in several UV lines have been
observed with the SUMER spectroheliometer onboard SOHO, and they have
been analysed to obtain oscillation spectra and phase differences
between lines of different ions. Lines intensities of neutral or
singly ionized atoms (with temperature of formation ≤ 30 000 K)
exhibit an increase of oscillatory power between 2.5 and 7 mHz, which
may be considered as the signature of p modes. Lines of highly ionized
elements (with a temperature of formation ≥ 50 000 K) yield power
spectra which are continuously decreasing with frequency. Brightness
variations of the continuum at different wavelengths between 1000
and 1400 Å present oscillations in the same frequency range. Thus,
p modes seem to be efficiently stopped by the transition region. No
clear evidence is found for the existence of a chromospheric oscillation
mode. Phase comparisons between lines formed at different altitudes
(in particular Si i and Si ii) indicate that these lines oscillate in
phase, within the precision of the measurements.

---------------------------------------------------------
Title: Doppler redistribution of resonance polarization of the O VI
103. 2 nm line observed above a polar hole
Authors: Raouafi, N. -E.; Sahal-Bréchot, S.; Lemaire, P.; Bommier, V.
1999ASSL..243..349R Altcode: 1999sopo.conf..349R
No abstract at ADS

---------------------------------------------------------
Title: Solar irradiances of UV and EUV lines during the minimum of
the sunspot activity in 1996
Authors: Wilhelm, K.; Lemaire, P.; Dammasch, I. E.; Hollandt, J.;
Schühle, U.; Curdt, W.; Kucera, T.; Hassler, D. M.; Huber, M. C. E.
1999AdSpR..24..229W Altcode:
Full Sun observations in UV and EUV emission lines were performed
by SUMER (Solar Ultraviolet Measurements of Emitted Radiation) on
SOHO (Solar and Heliospheric Observatory) in 1996. The radiometric
preflight calibration of SUMER is traceable to a primary radiometric
source standard - the electron storage ring BESSY. Based on this
calibration and on its inflight refinements, the irradiance values at
SOHO have been obtained for the lines He i (λ584.33), O v (λ629.74),
Ne viii (λ770.41), S v (λ786.47), O iv (λ787.72), S vi (λλ933.39,
944.52), H i Ly ɛ (λ937.80), C iii (λ977.04), N v (λ1238.81),
Si i (λ1256.52), and C iv (λ1548.20), and the continuum near 1549
Å. In this contribution, we compare our measurements with other recent
irradiance determinations and discuss, in particular, the observations
in the C iv line.

---------------------------------------------------------
Title: Search for Signatures of a Coronal Hole in Transition Region
Lines Near Disk Center
Authors: Lemaire, P.; Bocchialini, K.; Aletti, V.; Hassler, D.;
Wilhelm, K.
1999SSRv...87..249L Altcode:
The analysis of data taken by SUMER near disk center, where a small
coronal hole is observed in EIT images, is performed. From the
measurements of Doppler non-thermal velocities and intensities, we
search for the diagnostics and the signature of small scale structures
in the coronal hole using transition region lines. Transition region
lines in the range of 7 × 104 K to 2.5 × 105
K have a non-thermal velocity excess of 4.0 to 5.5 km s-1
relative to the contiguous quiet Sun. While the average intensity is
lower in the coronal hole than in the quiet area, this result shows
an increase of turbulence at the base of the high speed solar wind.

---------------------------------------------------------
Title: SUMER Measurements of Nonthermal Motions: Constraints on
Coronal Heating Mechanisms
Authors: Chae, Jongchul; Schühle, Udo; Lemaire, Philippe
1998ApJ...505..957C Altcode:
We have determined nonthermal velocities in the quiet Sun at
temperatures between 104 K and 2 × 106 K by
measuring the widths of a number of EUV and far-ultraviolet (FUV)
lines taken with SUMER on board the SOHO spacecraft. The broadenings
owing to the SUMER instrument and the finite opacity in each line
have been carefully examined. The nonthermal velocity at temperatures
below 2 × 104 K is smaller than 10 km s-1. The
velocity increases with temperature, reaches a peak value of 30
km s-1 around 3 × 105 K, and then decreases
with the temperature. The coronal nonthermal velocity is about 20 km
s-1. There exists a strong correlation between intensity
and nonthermal velocity at temperatures 2 × 104-1 ×
105 K. The correlation at higher temperatures weakens as
temperature increases. Furthermore, there is a spatial correlation
between the nonthermal velocities inferred from a set of any two lines
with temperatures below 2 × 105 K. Neither significant
center-to-limb variation nor meaningful dependence on the integration
time was found from the measured nonthermal velocities. We have
discovered the existence of high-velocity components in the observed
S VI λ933.4 line profiles. The average nonthermal velocity and
intensity fraction of this S VI line high-velocity component are found
to be 55 km s-1 and 0.25, respectively. Observational
characteristics of nonthermal motions carry some problems that should be
solved when interpreting observed nonthermal motions in terms of either
unresolved loop flows or Alfvén waves. The isotropic and very small
scale nature of the observed nonthermal motions appears to be suited to
the MHD turbulence interpretation of nonthermal motions. The turbulent
heating rates inferred from the measured nonthermal motions can account
for the radiative loss throughout the transition region and corona if
the nonthermal motions are truly turbulent motions whose mechanical
energy is injected at a scale of 1000 km (Kolmogorov-type turbulence)
or 15 km (Kraichnan-type turbulence). The existence of high-velocity
components at temperatures 6 × 104-2 × 105
K appears as observational evidence supporting nanoflare heating at
these temperatures.

---------------------------------------------------------
Title: The Si/Ne Abundance Ratio in Polar Coronal Hole and Quiet-Sun
Coronal Regions
Authors: Doschek, G. A.; Laming, J. M.; Feldman, U.; Wilhelm, K.;
Lemaire, P.; Schühle, U.; Hassler, D. M.
1998ApJ...504..573D Altcode:
Using spectra obtained from the Solar Ultraviolet Measurements
of Emitted Radiation (SUMER) spectrometer flown on the Solar and
Heliospheric Observatory (SOHO) spacecraft, we determine the Si/Ne
abundance ratio in diffuse, interplume polar coronal hole regions,
as well as the ratio relative to quiet-Sun coronal regions. Ne has
the second highest first ionization potential (FIP) of solar abundant
elements, and Si is a low-FIP element. Thus the Si/Ne ratio is a
sensitive indicator of abundance variations due to the FIP effect. We
develop new spectroscopic diagnostics for the determination of the
Si/Ne abundance ratio. Assuming ionization equilibrium, we find that
the Si/Ne abundance ratio in interplume polar coronal hole regions is
about a factor of 2 greater than the photospheric value and is close
to or the same as in coronal quiet-Sun regions. This result pertains
to the electron temperature range 5-8 × 105 K. However,
the combined atomic physics, instrumental, and statistical uncertainty
in this result is about a factor of 2, and therefore this observed
enhancement is consistent with no enhancement in the polar hole
abundances. Nevertheless, our results follow the same trend, i.e., a
greater than photospheric abundance ratio of low-FIP elements in the
corona relative to high-FIP elements, as found from other abundance
measurements in the corona that involve different atomic physics and
different instruments. Therefore we feel that our results reflect
an actual abundance enhancement, despite being within an uncertainty
level bar that encompasses photospheric abundances. We also examine
the Ne/Mg abundance ratio over a 24.5 hr observation and find no
significant abundance variations. (Mg is a low-FIP element.) Thus,
no large transient abundance variations appear to occur on timescales
shorter than about a day, although this result is based on only
one observation. From lines of Mg VII, Mg VIII, Mg IX, and Mg X we
find that the electron temperature along the line of sight increases
with height above the limb over the polar coronal holes, as has been
previously reported. We determine the emission measure distribution as
a function of height from Mg VII, Mg VIII, and Mg X lines. We determine
average temperatures along the line of sight over the polar holes from
Ne VIII/Ne VII, Mg VIII/Mg VII, and Si VIII/Si VII line ratios. We also
discuss the temperature properties of the coronal hole and quiet-Sun
regions using forbidden lines of Fe X and Fe XI. We comment on the
possibility that ionization equilibrium is not valid in polar coronal
hole regions, a possible scenario in light of recent observations that
show outflows in coronal holes beginning at about the temperature of
formation of Ne VIII.

---------------------------------------------------------
Title: High-Temperature Lines in SUMER Spectra Recorded Above a
Bright Solar Active Region
Authors: Feldman, U.; Curdt, W.; Doschek, G. A.; Schühle, U.; Wilhelm,
K.; Lemaire, P.
1998ApJ...503..467F Altcode:
We identify spectral lines emitted by solar abundant elements due
primarily to transitions within the 2s22pk and
3s23pk (where k = 1, 5) ground configurations
of ions that are formed in ionization equilibrium between 2 ×
106 and 8 × 106 K. The transitions were
identified in spectra of a bright active region recorded 1997
September 6, by the Solar Ultraviolet Measurements of Emitted Radiation
Spectrometer (SUMER) flown on the Solar and Heliospheric Observatory
(SOHO). Some of these lines provide useful plasma diagnostic tools
for measuring the physical conditions in the solar corona.

---------------------------------------------------------
Title: Measurement of the electron temperature gradient in a solar
coronal hole
Authors: David, C.; Gabriel, A. H.; Bely-Dubau, F.; Fludra, A.;
Lemaire, P.; Wilhelm, K.
1998A&A...336L..90D Altcode:
It has long been established that the high speed solar wind streams
observed at 1 A.U. originate from the coronal hole regions of the
Sun. Theoretical modelling of the acceleration mechanism depends
critically on the value of the maximum of temperature existing close
to the Sun. Measurements of the temperature in coronal holes prior
to SOHO are unreliable. The very low luminosity leads to extreme
observational difficulties, in particular due to light scattering in
the instrument telescopes. Using the two SOHO spectrometers CDS and
SUMER, electron temperatures have now been measured as a function of
height above the limb in a polar coronal hole. Temperatures of around
0.8 MK are found close to the limb, rising to a maximum of less than
1 MK at 1.15 R_sun, then falling to around 0.4 MK at 1.3 R_sun. With
these low temperatures, the classical Parker mechanism cannot alone
explain the high wind velocities, which must therefore be due to the
direct transfer of momentum from MHD waves to the ambient plasma.

---------------------------------------------------------
Title: Solar irradiances and radiances of UV and EUV lines during
the minimum of sunspot activity in 1996
Authors: Wilhelm, K.; Lemaire, P.; Dammasch, I. E.; Hollandt, J.;
Schuehle, U.; Curdt, W.; Kucera, T.; Hassler, D. M.; Huber, M. C. E.
1998A&A...334..685W Altcode:
Full Sun observations in UV and EUV emission lines were performed
by SUMER (Solar Ultraviolet Measurements of Emitted Radiation) on
SOHO (Solar and Heliospheric Observatory) in 1996. The radiometric
pre-flight calibration of SUMER is traceable to a primary radiometric
source standard - the electron storage ring BESSY. Based on this
calibration, the irradiance values at SOHO and at 1 AU have been
obtained for the lines He i (lambda 584.33 { Angstroms}), O v (lambda
629.74 { Angstroms}), Ne viii (lambda 770.41 { Angstroms}), S v (lambda
786.47 { Angstroms}), O iv (lambda 787.72 { Angstroms}), S vi (lambda
lambda 933.39, 944.52 { Angstroms}), H i Ly epsilon (lambda 937.80 {
Angstroms}), C iii (lambda 977.04 { Angstroms}), N v (lambda 1238.81
{ Angstroms}), Si i (lambda 1256.52 { Angstroms}), and C iv (lambda
1548.20 { Angstroms}). The spatially resolved measurements allowed
good estimates to be made of the active region contributions to the
irradiance of the quiet Sun. The centre-to-limb radiance variations of
these lines have also been obtained from these measurements. For quiet
solar conditions, a radiance spectrum was determined for wavelengths
from 800 { Angstroms} to 1500 { Angstroms} near the centre of the
solar disk.

---------------------------------------------------------
Title: The Solar Corona Above Polar Coronal Holes as Seen by SUMER
on SOHO
Authors: Wilhelm, Klaus; Marsch, Eckart; Dwivedi, Bhola N.; Hassler,
Donald M.; Lemaire, Philippe; Gabriel, Alan H.; Huber, Martin C. E.
1998ApJ...500.1023W Altcode:
In order to address two of the principal scientific objectives of the
Solar and Heliospheric Observatory (SOHO), studies of the heating
mechanisms of the solar corona and the acceleration processes of
the solar wind, we deduce electron temperatures, densities, and
ion velocities in plumes and interplume regions of polar coronal
holes using ultraviolet observations from SUMER (Solar Ultraviolet
Measurements of Emitted Radiation) on SOHO. SUMER allows us to study
the inner corona up to a distance of about 430,000 km above the
limb, or r = 1.6 R⊙ (solar radius) from the center
of the disk. We find the electron temperatures, Te,
to be less than 800,000 K in a plume in the range from r = 1.03 to
1.60 R⊙, decreasing with height to ~330,000 K. Near
an interplume lane, the electron temperature is also low, but stays
between 750,000 and 880,000 K in the same height interval. Doppler
widths of O VI lines in plumes are narrower (ΔλD ~
150 mÅ, v1/E ~ 43 km s-1) than in interplume
lanes (~190 mÅ, ~55 km s-1). The thermal and turbulent
ion speeds, v1/E, of Si7+ reach values up to
~80 km s-1 in the darkest regions outside plumes above the
coronal hole. This corresponds to a kinetic ion temperature of 1 ×
107 K. A limit of ~18 km s-1 for the bulk speed
in plumes below r = 1.2 R⊙ is deduced from O VI line shift
measurements and consideration of the three-dimensional plume geometry
(differential line-of-sight velocities &lt;=3 km s-1),
whereas differential line-of-sight velocities of Mg8+
ions up to 34 km s-1 can be seen in dark regions.

---------------------------------------------------------
Title: Solar H i Lyman alpha full disk profile obtained with the
SUMER/SOHO spectrometer
Authors: Lemaire, P.; Emerich, C.; Curdt, W.; Schuehle, U.; Wilhelm, K.
1998A&A...334.1095L Altcode:
An uncalibrated solar hydrogen Lyman alpha profile was obtained with
the use of the spectrometer on SOHO. The collection of the light
scattered by the telescope permitted to average the profile over
the full solar disk. The profile taken at the L1 Sun-Earth
Lagrangian position is free of the central geocoronal absorption. Then,
taking advantage of the absolute flux measured by the SOLSTICE/UARS
spectrometer, an absolute line profile intensity is derived, and is
compared with previous observations at minimum solar activity.

---------------------------------------------------------
Title: The Magnetic Reconnection Explorer (MAGREX)
Authors: Schühle, U.; Antionchos, S. K.; Barbee, T. W., Jr.; Bixler,
J. V.; Brown, C. M.; Carter, P. H., II; Curdt, W.; Davila, J. M.;
Doschek, G.; Feldman, U.; Goldstein, W. H.; Kordas, J.; Lemaire, P.;
Mariska, J. T.; Marsch, E.; Moses, J. D.; Seely, J. F.; Wilhelm, K.;
Woods, T. N.
1998ESASP.417..289S Altcode: 1998cesh.conf..289S
No abstract at ADS

---------------------------------------------------------
Title: EUV and Microwave Observations of a Filament
Authors: Chiuderi-Drago, F.; Bocchialini, K.; Lamartinie, S.;
Vial, J. -C.; Bastian, T.; Alissandrakis, C. E.; Harrison, R.;
Delaboudiniere, J. -P.; Lemaire, P.
1998ASPC..150...55C Altcode: 1998IAUCo.167...55C; 1998npsp.conf...55C
No abstract at ADS

---------------------------------------------------------
Title: New Requirements for Transition Region to Low Corona
Observations with FUV-EUV Spectrometers Derived from SOHO Experience
Authors: Lemaire, P.
1998ESASP.417..325L Altcode: 1998cesh.conf..325L
No abstract at ADS

---------------------------------------------------------
Title: Instrumentation: Spectroscopy
Authors: Lemaire, Philippe
1998LNP...507..245L Altcode: 1998sspt.conf..245L
Our knowledge of the the solar atmosphere comes from the light
analysis. The ultraviolet wavelength is the privileged spectral range
to study the solar plasma in several stages of ionization emitted
from the chromosphere to the corona. Starting with basic notions of
spectroscopy, an overview of important parameters is given. Then, after
a short description of classical spectrometers, a detailed analysis
of the properties of the mountings used on SOHO is performed; some
examples are shown. I discuss how to separate the real solar signal
from the instrumental contribution.

---------------------------------------------------------
Title: The solar disk spectrum between 660 and 1175 Anstroms (first
order) obtained by SUMER on SOHO
Authors: Curdt, W.; Feldman, U.; Laming, J. M.; Wilhelm, K.; Schuehle,
U.; Lemaire, P.
1997A&AS..126..281C Altcode:
SUMER -- Solar Ultraviolet Measurements of Emitted Radiation -- onboard
of SOHO -- Solar and Heliospheric Observatory -- obtained its first
spectrum on January 25, 1996 near the north polar limb. The range
from 660 Angstroms to 1175 Angstroms which has never before been
observed with such a good spectral resolution contains a wealth of
spectroscopic details. Identification of about 400 lines in this
spectral range is given. We list the wavelengths of identified
transitions and provide their absolute peak intensities. General
spectral features of the most abundant elements H, He, C, N, O,
Ne, Mg, Si, S, Ar, and Fe are described. In this spectral range
many density- and temperature-sensitive line pairs are found. It is
shown in examples how they can be used as diagnostic tools. Table
1 and Fig.nearlimb are also available in digital form at the CDS
via anonymous ftp to cdsarc.u-strasbg. fr (130.79.128.5) or via
http://cdsweb.u-strasbg.fr/Abstract.html

---------------------------------------------------------
Title: The Off-Limb Behaviour of the Solar Transition Region FIP
Effect
Authors: Laming, J. M.; Feldman, U.; Drake, J. J.; Schuhle, U.; Curdt,
W.; Wilhelm, K.; Lemaire, P.
1997AAS...191.7301L Altcode: 1997BAAS...29.1320L
We investigate the behaviour of the solar FIP effect (the abundance
enhancement of elements with first ionization potential &lt; 10 eV by
factor of 3-4 in the corona with respect to photospheric values) with
height above the limb in a region of diffuse quiet corona observed
by the SUMER instrument on SOHO. Line ratios formed at log T &gt;
5.8 show coronal abundances for all heights. Line ratios formed at
lower temperatures are consistent with coronal abundances well off the
limb, with the apparent magnitude of the FIP enhancement decreasing
by a factor of 1.5 - 2 as one approaches the solar limb. Thus our
observations support a spatial variation in the quiet sun transition
region FIP effect inferred previously from studies of the full disk
solar spectrum (Laming, Drake, &amp; Widing 1995, ApJ, 443, 416
and references therein). This result adds to the probability that
emission from the solar disk transition region and corona originates
from qualitatively different structures for values of log T {&lt;atop
&gt;} 5.8, having different FIP effects.

---------------------------------------------------------
Title: A Coronal Spectrum in the 500--1610 Angstrom Wavelength Range
Recorded at a Height of 21,000 Kilometers above the West Solar Limb
by the SUMER Instrument on Solar and Heliospheric Observatory
Authors: Feldman, U.; Behring, W. E.; Curdt, W.; Schühle, U.; Wilhelm,
K.; Lemaire, P.; Moran, T. M.
1997ApJS..113..195F Altcode:
We present a solar coronal spectrum recorded by the extreme UV
spectrometer SUMER on the Solar and Heliospheric Observatory. The
spectrum was taken between 21:28 UT on 1996 June 25 and 02:47 UT on
1996 June 26, at a height of 21,000 km above the west equatorial limb
with the slit oriented in the north-south direction. At the time of
the observations the Sun was rather quiet, and the west limb appeared
“devoid of any activity.” The spectrum, which covers the 500-1610
Å wavelength range, originates from plasmas with temperatures
ranging between 1.5 × 104 and 1.5 × 106
K. Identification of lines originating from different temperature
regimes is facilitated by the appearance of their intensity along the
300" long slit. Well over 800 lines have been found, many of which
were not previously observed. We present the entire spectrum and discuss
line identifications. A table of the wavelengths of lines observed,
with their identifications and peak intensities, is provided. Although
we have identified lines previously detected in laboratory plasmas and
a number of new lines not previously observed, over 40% of the SUMER
lines remain unidentified. Among the newly detected lines, some have
a potential as plasma density diagnostics.

---------------------------------------------------------
Title: Observations of Polar Plumes with the SUMER Instrument on SOHO
Authors: Hassler, D. M.; Wilhelm, K.; Lemaire, P.; Schühle, U.
1997SoPh..175..375H Altcode:
We present new observations of O vi 1032 Å line profiles in polar
plumes, and inter-plume regions, on the disk and above the limb in
the north coronal hole obtained with the SUMER (Solar Ultraviolet
Measurements of Emitted Radiation) instrument on the SOHO (Solar and
Heliospheric Observatory) spacecraft. On 22 May 1996, a 5 x 5 arc min
spectroheliogram was scanned above the north polar coronal hole with
the entrance slit extending from 1.03 to 1.33 solar radii with 1.5 arc
sec spatial resolution and ≈ 0.044 Å per pixel spectral resolution
in the wavelength range 1020-1040 Å. Detailed plume structure in
O vi 1032 Å can be seen extending beyond 1.3 solar radii, with
intensities in the plume regions 10-50% brighter, but line widths
10-15% narrower, than the inter-plume regions. Possible explanations
for this observed anti-correlation between line width and intensity
in the plume and inter-plume regions are discussed. We conclude that
the source of the high-speed solar wind may not be polar plumes, but
the inter-plume lanes associated with open magnetic field regions of
the chromospheric network.

---------------------------------------------------------
Title: Radiometric calibration of SUMER: refinement of the laboratory
results under operational conditions on SOHO
Authors: Wilhelm, Klaus; Lemaire, Philippe; Feldman, Uri; Hollandt,
Jörg; Schühle, Udo; Curdt, Werner
1997ApOpt..36.6416W Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Electron Density Diagnostics for the Solar Upper Atmosphere
from Spectra Obtained by SUMER/SOHO
Authors: Laming, J. M.; Feldman, U.; Schühle, U.; Lemaire, P.; Curdt,
W.; Wilhelm, K.
1997ApJ...485..911L Altcode:
We evaluate the electron density in various solar regions above the
limb observed by the Solar Ultraviolet Measurement of Emitted Radiation
(SUMER) instrument on SOHO. We find in general good agreement among
line ratios from Be-, B-, N-, and Mg-like ions, giving densities of
order 108 cm-3.

---------------------------------------------------------
Title: Turbulent Velocities and Ion Temperatures in the Solar Corona
Obtained from SUMER Line Widths
Authors: Seely, J. F.; Feldman, U.; Schühle, U.; Wilhelm, K.; Curdt,
W.; Lemaire, P.
1997ApJ...484L..87S Altcode:
Turbulent plasma velocities and ion temperatures were determined from
the line widths recorded by the Solar Ultraviolet Measurements of
Emitted Radiation instrument on the Solar and Heliospheric Observatory
spacecraft. From the widths of the lines of five light elements
(Ne, Na, Mg, Si, and S) and a heavy element (Fe), it was possible
to determine the contributions of turbulent plasma motion and ion
thermal motion to the line widths. The results indicated that the
turbulent velocity was approximately 22 km s-1 at 30"
above the limb and decreased to less than 10 km s-1 at 109"
and 209" above the limb. At 30" above the limb, the ion temperatures
of the hotter lines were comparable to the electron temperatures for
ionization equilibrium. The ion temperatures of the cooler lines were
higher than the ionization equilibrium temperatures; at 109" and 209"
above the limb, the ion temperatures were at least a factor of 2.5
higher than the ionization equilibrium temperatures.

---------------------------------------------------------
Title: Doppler Shifts and Nonthermal Broadening in the Quiet Solar
Transition Region: O VI
Authors: Warren, H. P.; Mariska, J. T.; Wilhelm, K.; Lemaire, P.
1997ApJ...484L..91W Altcode:
Using observations from the Solar Ultraviolet Measurements of Emitted
Radiation (SUMER) experiment flown on the Solar and Heliospheric
Observatory (SOHO) spacecraft, we have measured Doppler wavelength
shifts and nonthermal broadening in the 1032 and 1038 Å emission lines
of O VI and the 1036 and 1037 Å emission lines of C II. Near Sun center
the C II lines exhibit an average redshift of 2 +/- 3 km s-1,
consistent with earlier observations in this temperature range. The
O VI emission lines exhibit average Doppler velocities of 5 +/- 3
km s-1, suggesting the presence of redshifted material at
2.9 × 105 K. For the O VI lines, the average nonthermal
component of the observed line width is 34 +/- 3 km s-1.

---------------------------------------------------------
Title: Electron Densities in the Solar Polar Coronal Holes from
Density-Sensitive Line Ratios of Si VIII and S X
Authors: Doschek, G. A.; Warren, H. P.; Laming, J. M.; Mariska, J. T.;
Wilhelm, K.; Lemaire, P.; Schühle, U.; Moran, T. G.
1997ApJ...482L.109D Altcode:
We derive electron densities as a function of height in the north and
south polar coronal holes from a forbidden spectral line ratio of Si
VIII. Si VIII is produced at about 8 × 105 K in ionization
equilibrium. We also derive densities from a similar line ratio of S X
(1.3 × 106 K). The spectra were obtained with the Solar
Ultraviolet Measurements of Emitted Radiation spectrometer flown on
the Solar and Heliospheric Observatory spacecraft. In addition to the
primary mechanism of electron impact excitation, the derivation of
theoretical level populations for Si VIII and S X includes both proton
and resonance capture excitation. We compare the coronal hole results
to quiet-Sun coronal measurements obtained outside the east and west
limbs. We find for distances of a few arcseconds outside the solar
limb that the average line-of-sight electron densities in the coronal
holes are about a factor of 2 lower than in quiet-Sun regions. The
decrease of density with height is exponential in the polar holes. We
also confirm the result known from a variety of earlier observations
that the temperature of most of the plasma in coronal holes does not
exceed about 106 K.

---------------------------------------------------------
Title: Translimb Spectroscopy with SOHO/SUMER
Authors: Ayres, T. R.; Lemaire, P.; Schuhle, U.; Wilhelm, K.; Ruedi,
I.; Solanki, S.
1997SPD....28.0104A Altcode: 1997BAAS...29..879A
We have used SUMER to obtain deep exposures of the 1300--1400 Angstroms
spectrum, at the extreme limb and off-limb. Previous “translimb”
studies in the thermal infrared had revealed remarkable extensions
of cold material (T ~ 3000 K)---traced by carbon monoxide emission
lines---into the heart of the hot chromosphere. A main objective of
our program was to search for corresponding far-UV signatures of the
“thermally-bifurcated” low chromosphere; for example, radiatively
fluoresced emissions of the CO A--X 4th-positive system (collisional
excitation would be negligible in cold gas). We conducted two separate
observing programs with SUMER. Both made use of the 1(”) -diameter
circular aperture, translated across the limb in the minimum motor
step increments of 0.(”) 375, along the central meridian in the
Northern polar coronal hole. The first program executed for nine hours
beginning 19UT 25 Oct 1996. The full wavelength range was 1340--1400
Angstroms. It was recorded in two overlapping segments, placing key
regions of the spectrum alternately on the KBr and bare parts of
the detector, to help isolate 2nd-order features. Each segment was
integrated for 500 s, and 32 pairs were obtained to span a 12(”)
swath centered on the optical limb. The second program was conducted
00--09UT 01 Dec 1996. It consisted of a single wavelength setting
(1300--1340 Angstroms) with exposure time 500 s, but twice the spatial
coverage of the earlier series: 64 steps, for a total displacement
of 24(”) . The strong chromospheric resonance lines of atomic oxygen
(1302--1305 Angstroms) and ionized carbon (1334--1335 Angstroms) were
observed on the bare part of the MCP camera. We report our progress
in cataloging the rich, diverse translimb emission spectrum; and our
efforts to deduce fundamental properties of the thermally heterogeneous
chromosphere. [-3mm] SOHO is a project of international cooperation;
the participation of TRA was supported by NASA grant NAG5-3226.

---------------------------------------------------------
Title: The Electron Density, Temperature, and Si/Ne Abundance Ratio
in Polar Coronal Holes from SUMER
Authors: Doschek, G. A.; Laming, J. M.; Warren, H. P.; Lemaire, P.;
Wilhelm, K.
1997SPD....28.0404D Altcode: 1997BAAS...29Q.908D
The Solar Ultraviolet Measurements of Emitted Radiation (SUMER)
spectrometer flown on the Solar and Heliospheric Observatory (SOHO)
covers a wavelength range with spectral and spatial resolution and
sensitivity not previously obtained by any other solar spectrometer
experiment. Consequently, new plasma diagnostic techniques have been
used and developed to measure plasma parameters such as electron
density. In this paper we discuss the electron density as a function
of height above the solar surface in the polar coronal holes as
determined from line ratios of Si VIII and S X. The densities vary
between about 3 x 10(6) cm(-3) and 10(8) cm(-3) . We determine the
emission measure at selected temperatures as a function of position
above the polar limbs from lines of Mg VII, Mg VIII, Mg IX, and Mg
X. The electron temperature is lower in the polar holes than in the
quiet Sun. This result is also based on intensities of lines of Fe X,
Fe XI, and Fe XII. We determine the Si/Ne abundance ratio (low/high
first ionization potential elements) using lines of Ne VII, Ne VIII,
Si VII, and Si VIII. The preliminary result is that the Si/Ne abundance
ratio in interplume regions is close to photospheric. We also compare
the coronal hole density and abundance results with similar results
obtained for the quiet Sun in the east and west coronal streamers. We
discuss our conclusions in light of results from previous missions.

---------------------------------------------------------
Title: New Insights into the Physical Mechanisms of Polar Plumes
with Observations from the SUMER Instrument on SOHO
Authors: Hassler, Donald M.; Wilhelm, Klaus; Lemaire, Philippe;
Schuehle, Udo
1997SPD....28.0802H Altcode: 1997BAAS...29..912H
SUMER (Solar Ultraviolet Measurements of Emitted Radiation)
line profiles above the limb in coronal holes are important for
constraining thermodynamic models governing the outflow of the solar
wind. Observational constraints in terms of thermal and nonthermal
velocities, and upper limits on wave velocity amplitudes can be directly
compared with in-situ observations. We present new observations of
line profiles in polar plumes, and inter-plume regions, above the
limb in coronal holes obtained with the SUMER instrument on the SOHO
spacecraft. Detailed structure can be seen extending beyond 1.5 solar
radii (out to the edge of the SUMER field-of-view), with intensities in
the plume regions roughly 10-50% brighter than the inter-plume regions,
but line widths in the plumes roughly 10% narrower than the inter-plume
regions. Possible explanations for this observed anti-correlation
between line width and intensity, and the correspondence with observed
in-situ solar wind signatures will be discussed.

---------------------------------------------------------
Title: Observations of Doppler Shifts and Nonthermal Broadening in
the North Polar Coronal Hole and Adjacent Quiet Sun
Authors: Mariska, J. T.; Warren, H. P.; Wilhelm, K.; Lemaire, P.
1997SPD....28.0118M Altcode: 1997BAAS...29..882M
Coronal holes are thought to be the source of high-speed solar
wind streams. It is, however, unclear at what height the outflow
of material first becomes apparent. Using the Solar Ultraviolet
Measurements of Emitted Radiation (SUMER) experiment on the Solar and
Heliospheric Observatory (SOHO), we have obtained observations in the
north polar coronal hole, its boundary region, and the adjacent quiet
Sun at wavelengths that cover emission lines of O VI at 1032 and 1038
Angstroms, Ne VIII at 770 Angstroms, and Mg X at 625 Angstroms. These
lines are formed at temperatures of 0.3, 0.8, and 1.25 MK, respectively,
and should thus help to determine the temperature at which outflows
are first detected. For O VI and Mg X, we will report on Doppler shift
measurements made relative to cooler chromospheric lines. Since there
are no suitable emission lines from ions formed in the chromosphere
for the Ne VIII line, we are only able to measure relative differences
between the coronal hole and the adjacent quiet Sun. We will also
report on the magnitude of the nonthermal broadening in these lines
in the different solar regions. This work was supported by a NASA SOHO
Guest Investigator Program grant.

---------------------------------------------------------
Title: Doppler Shifts and Nonthermal Broadening in the Quiet Solar
Transition Region: O VI
Authors: Warren, H. P.; Mariska, J. T.; Wilhelm, K.; Lemaire, P.
1997SPD....28.0117W Altcode: 1997BAAS...29..882W
Using observations from the Solar Ultraviolet Measurements of Emitted
Radiation (SUMER) experiment flown on the Solar and Heliospheric
Observatory (SOHO ) spacecraft, we have measured Doppler wavelength
shifts and nonthermal broadening in the 1032 and 1038 Angstroms emission
lines of Ovi and the 1036 and 1037 Angstroms emission lines of Cii. Near
Sun center the Cii lines exhibit an average redshift of 2+/-3km s(-1)
, consistent with earlier observations in this temperature range. The
Ovi emission lines exhibit average Doppler velocities of 5+/-3km s(-1)
suggesting the presence of redshifted material at 2.9*E(5) K. For the
Ovi lines, the average nonthermal component of the observed line width
is 34+/-3km s(-1) . These observations indicate a tendency for brighter
regions to have larger average redshifts and line widths than faint
features although the relationship is very weak. Preliminary analysis of
observations at the limb suggests that the Doppler velocities for Ovi do
not approach zero as would be expected for predominately radial motions.

---------------------------------------------------------
Title: VizieR Online Data Catalog: Solar disk spectrum (660-1175A)
(Curdt+ 1997)
Authors: Curdt, W.; Feldman, U.; Laming, J. M.; Wilhelm, K.; Schuehle,
U.; Lemaire, P.
1997yCat..41260281C Altcode:
The near-limb quiet-Sun spectrum recorded on January 25, 1996
near the solar North pole is presented in tabular form and in
graphical form. Table 1 - the line list - lists all lines found
in the spectrum providing absolute peak intensities, measured and
literature wavelengths, identification, and classification of the
transition. Fig. 4 is a display the composite spectrum. The most
prominent lines are labelled. In this figure intensities are given in
instrumental units and logarithmic scale. (1 data file).

---------------------------------------------------------
Title: Determination of the Formation Temperature of Si IV in the
Solar Transition Region
Authors: Doschek, G. A.; Mariska, J. T.; Warren, H. P.; Wilhelm, K.;
Lemaire, P.; Kucera, T.; Schühle, U.
1997ApJ...477L.119D Altcode:
Using spectra obtained with the Solar Ultraviolet Measurements
of Emitted Radiation (SUMER) spectrometer flown on the Solar and
Heliospheric Observatory spacecraft, we deduce the temperature
of formation of the Si IV ion in the solar transition region
from the Si IV ultraviolet spectral line intensity ratio, 3p
2P3/2-3d 2D3/2,5/2/3s
2S1/2-3p 2P1/2,
and compare the result to the temperature predicted under the
assumption of ionization equilibrium. The wavelengths are as
follows: 2D3/2,5/2, 1128.325, 1128.340 Å
2P1/2, 1402.770 Å. Ratios are derived for
typical features of the quiet Sun, such as cell center and network,
and are systematically higher than those predicted at the 6.3 ×
104 K ionization equilibrium temperature of formation
of Si IV. For most solar features the ratios imply a temperature
of formation of about 8.5 × 104 K. The ratios for the
faintest features imply a temperature of formation of up to 1.6 ×
105 K. It is not clear, however, that all the discrepancies
between the measured and theoretical ratios are due to a temperature
effect. Accurate temperature measurements are important since a large
discrepancy from ionization equilibrium has significant implications
for the physics of the transition region, such as the possible presence
of nonthermal electrons.

---------------------------------------------------------
Title: Working Group 2: Flows of Mass, Momentum and Energy
Authors: Lemaire, P.
1997ESASP.404..131L Altcode: 1997cswn.conf..131L
No abstract at ADS

---------------------------------------------------------
Title: First Results from SOHO on Waves Near the Solar Transition
Region
Authors: Steffens, S.; Deubner, F. -L.; Fleck, B.; Wilhelm, K.;
Schuhle, U.; Curdt, W.; Harrison, R.; Gurman, J.; Thompson, B. J.;
Brekke, P.; Delaboudiniere, J. -P.; Lemaire, P.; Hessel, B.; Rutten,
R. J.
1997ASPC..118..284S Altcode: 1997fasp.conf..284S
We present first results from simultaneous observations with the
CDS, EIT and SUMER instruments {please see Solar Physics 162 (1995)
for a description of the instruments} onboard SOHO and the VTT at
Tenerife. Our aim is to study the wave propagation, shock formation,
and transmission properties of the upper chromosphere and transition
region. The preliminary results presented here include the variation
of velocity power spectra with height, difference in power between
internetwork and network regions, and variations in mean flows displayed
by different spectral lines.

---------------------------------------------------------
Title: A New Look at the Quiet Sun Network in the Upper Atmosphere
During a Minimum of Activity Cycle
Authors: Lemaire, P.; Schuehle, U.; Curdt, W.; Wilhelm, K.; Poland,
A.; Falciani, R.
1997ESASP.404..517L Altcode: 1997cswn.conf..517L
No abstract at ADS

---------------------------------------------------------
Title: First Results of the SUMER Telescope and Spectrometer on SOHO -
I. Spectra and Spectroradiometry
Authors: Wilhelm, K.; Lemaire, P.; Curdt, W.; Schühle, U.; Marsch, E.;
Poland, A. I.; Jordan, S. D.; Thomas, R. J.; Hassler, D. M.; Huber,
M. C. E.; Vial, J. -C.; Kühne, M.; Siegmund, O. H. W.; Gabriel, A.;
Timothy, J. G.; Grewing, M.; Feldman, U.; Hollandt, J.; Brekke, P.
1997SoPh..170...75W Altcode:
SUMER - the Solar Ultraviolet Measurements of the Emitted Radiation
instrument on the Solar and Heliospheric Observatory (SOHO) - observed
its first light on January 24, 1996, and subsequently obtained a
detailed spectrum with detector B in the wavelength range from 660
to 1490 Å (in first order) inside and above the limb in the north
polar coronal hole. Using detector A of the instrument, this range
was later extended to 1610 Å. The second-order spectra of detectors
A and B cover 330 to 805 Å and are superimposed on the first-order
spectra. Many more features and areas of the Sun and their spectra
have been observed since, including coronal holes, polar plumes and
active regions. The atoms and ions emitting this radiation exist at
temperatures below 2 × 106 K and are thus ideally suited
to investigate the solar transition region where the temperature
increases from chromospheric to coronal values. SUMER can also be
operated in a manner such that it makes images or spectroheliograms
of different sizes in selected spectral lines. A detailed line profile
with spectral resolution elements between 22 and 45 mÅ is produced for
each line at each spatial location along the slit. From the line width,
intensity and wavelength position we are able to deduce temperature,
density, and velocity of the emitting atoms and ions for each emission
line and spatial element in the spectroheliogram. Because of the high
spectral resolution and low noise of SUMER, we have been able to detect
faint lines not previously observed and, in addition, to determine
their spectral profiles. SUMER has already recorded over 2000 extreme
ultraviolet emission lines and many identifications have been made on
the disk and in the corona.

---------------------------------------------------------
Title: SOHO observations of the north polar solar wind
Authors: Peres, G.; Ciaravella, A.; Betta, R.; Orlando, S.; Reale,
F.; Kohl, J.; Noci, G.; Fineschi, S.; Romoli, M.; Brekke, P.; Fludra,
A.; Gurman, J. B.; Lemaire, P.; Schuhle, U.
1997ESASP.404..587P Altcode: 1997cswn.conf..587P
No abstract at ADS

---------------------------------------------------------
Title: High resolution solar ultraviolet measurements
Authors: Lemaire, P.; Wilhelm, K.; Schühle, U.; Curdt, W.; Poland,
A. I.; Jordan, S. D.; Thomas, R. J.; Hassler, D. M.; Vial, J. -C.
1997AdSpR..20.2249L Altcode:
The increase of our understanding of the processes acting in the solar
corona and maintaining it is strongly dependent on the quality of the
data that are obtained to check theories. The fine structure of the
solar atmosphere seen from the photosphere and extending to the hottest
parts of the corona requires data with high resolution in all parameter
space (angular, spectral and temporal). To constrain the hypotheses that
are proposed to describe the solar corona, it is necessary to establish
an accurate energy budget taking into account the processes which are
acting from the chromosphere to the corona. Some requirements can be
established and compared with the data collected so far (or about to
be collected) with the present SUMER (Solar Utraviolet Measurements
of Emitted Radiations) instrumentation.

---------------------------------------------------------
Title: Polarization sensitivity of the SUMER instrument on SOHO
Authors: Hassler, D. M.; Lemaire, P.; Longval, Y.
1997ApOpt..36..353H Altcode:
No abstract at ADS

---------------------------------------------------------
Title: First Results of the SUMER Telescope and Spectrometer on SOHO -
II. Imagery and Data Management
Authors: Lemaire, P.; Wilhelm, K.; Curdt, W.; SchÜle, U.; Marsch,
E.; Poland, A. I.; Jordan, S. D.; Thomas, R. J.; Hassler, D. M.; Vial,
J. C.; KÜhne, M.; Huber, M. C. E.; Siegmund, O. H. W.; Gabriel, A.;
Timothy, J. G.; Grewing, M.
1997SoPh..170..105L Altcode:
SUMER - Solar Ultraviolet Measurements of Emitted Radiation - is not
only an extreme ultraviolet (EUV) spectrometer capable of obtaining
detailed spectra in the range from 500 to 1610 Å, but, using the
telescope mechanisms, it also provides monochromatic images over
the full solar disk and beyond, into the corona, with high spatial
resolution. We report on some aspects of the observation programmes
that have already led us to a new view of many aspects of the Sun,
including quiet Sun, chromospheric and transition region network,
coronal hole, polar plume, prominence and active region studies. After
an introduction, where we compare the SUMER imaging capabilities to
previous experiments in our wavelength range, we describe the results
of tests performed in order to characterize and optimize the telescope
under operational conditions. We find the spatial resolution to be
1.2 arc sec across the slit and 2 arc sec (2 detector pixels) along
the slit. Resolution and sensitivity are adequate to provide details
on the structure, physical properties, and evolution of several solar
features which we then present. Finally some information is given on
the data availability and the data management system.

---------------------------------------------------------
Title: Building the Spectrum of a G2V Star During a Minimum of
Activity Cycle
Authors: Lemaire, P.; Schuehle, U.; Curdt, W.; Wilhelm, K.; Hassler, D.
1997ESASP.404..513L Altcode: 1997cswn.conf..513L
No abstract at ADS

---------------------------------------------------------
Title: Microwave and UV observations of filaments with SOHO and
the VLA
Authors: Alissandrakis, C. E.; Drago, F.; Bastian, T.; Bocchialini,
K.; Delaboudiniere, J. -P.; Lemaire, P.; Vial, J. -C.; Harrison,
R. A.; Thompson, B.
1997ASPC..118..289A Altcode: 1997fasp.conf..289A
Observations performed in coordination between SOHO instruments and
ground-based observatories offer the unique possibility to derive
information simultaneously in several wavelengths formed at different
altitudes and/or temperatures in the solar atmosphere. The SUMER and
CDS spectrometers, the imaging telescope EIT aboard SOHO, and the VLA
provide complementary information in the UV and the radio ranges. We
illustrate such a coordination with observations of filaments in the
transition region, performed in July 1996. The observations in the UV
between 10(4) and 10(6) K provide the differential emission measure
as a function of temperature; this can be used to compute the expected
brightness temperature in the microwave range and check models of the
filament-corona transition region.

---------------------------------------------------------
Title: Coordinated SOHO Observations of Polar Plumes
Authors: Deforest, C. E.; Scherrer, P. H.; Tarbell, T.; Harrison,
R. A.; Fludra, A.; Delaboudiniere, J. P.; Gurman, J. B.; Wilhelm,
K.; Lemaire, P.; Hassler, D. M.; Kohl, J. L.; Noci, G.; Fineschi,
S.; Brueckner, G. E.; Howard, R. A.; Cyr, O. C. St.
1996AAS...188.4909D Altcode: 1996BAAS...28R.898D
On 7 and 8 March 1996, SOHO instruments engaged in their first
joint science operation, a 12-hr observation of polar plumes
over the South polar coronal hole. The observing mini-campaign
included observations from SOHO, other spacecraft, and ground-based
observatories. Contributing SOHO instruments -- in order of altitude,
MDI, CDS, SUMER, EIT, UVCS, and LASCO -- made overlapping, simultaneous
observations of plume structures from the photosphere out to the
LASCO C3 limit of 32 solar radii. MDI provided line-of-sight surface
magnetograms with a one-min cadence and 0.6 arcsec resolution;
CDS, SUMER, and EIT supplied temperature-sensitive images of the
lower corona with varying cadences and resolutions; UVCS measured
fluctuations in Ly B intensity across the coronal hole with a one-min
cadence at 1.4 R0; and LASCO imaged the entire corona out to 30 R0 in
various visible passbands. Plume footpoints in the lower corona are
observed by EIT and CDS to vary by a factor of two in EUV brightness
with a timescale of tens of minutes, while the structures above are
(as as been previously observed) quiescent on at least a ten-hr time
scale. We present preliminary results of cross-instrument analysis
of the observed plumes, and suggest how this and similar future data
sets can be used to constrain quiet-sun wind acceleration and coronal
heating models for the coronal hole. This research is supported by
the SOI-MDI NASA contract NAG5-3077 at Stanford University. SOHO is
project of international cooperation between NASA and ESA.

---------------------------------------------------------
Title: A Solar EUV Spectral Atlas Observed with SUMER
Authors: Brekke, P.; Wilhelm, K.; Lemaire, P.; Curdt, W.; Schuhle,
U.; Poland, A.; Kucera, T.; Hassler, D. M.; Siegmund, O. H. W.
1996AAS...188.3713B Altcode: 1996BAAS...28..879B
We present the first solar EUV spectral atlas in the wavelength range
500 -- 1600 { Angstroms}. The spectra were recorded with the Solar
Ultraviolet Measurements of Emitted Radiation (SUMER) which is part
of the ESA/NASA Solar and Heliospheric Observatory (SOHO). The solar
spectrum below 1200 { Angstroms} is not very well known. Thus, the
present spectral atlas, and SUMER observations in general, represents
a new important diagnostic tool to study essential physical parameters
of the solar atmosphere. It includes emission from atoms and ions in
the temperature range 10(4) to 2 x 10(6) K. Thus, emission lines and
continua emitted from the lower chromosphere to the lower corona
can be studied. The atlas is also useful as a planning tool for
SUMER studies to determine useful dwell times, possible blends, and
to select proper data extraction windows. The angular resolution of
SUMER is close to 1 arcsec, but the atlas presented here represents an
average along part of the 1-arcsec wide slit, typically 30 arcsec. The
spectral resolving power of the instrument is lambda /Delta lambda =
17770-38300. For more details about the SUMER instrument we refer to
Wilhelm et al. (Solar Physics, 162, 189, 1995). The spectral data in
this atlas were obtained with the spectrometer slit positioned at the
center of the solar disk with a dwell time of 300 s to bring up weak
lines and continua. The full spectral range was put together from
a number of exposures each covering approximately 20 { Angstroms}
in 1st order on the coated, and therefore most sensitive, part (KrB)
of the detector. 1st and 2nd order spectra are superimposed. The
spectral atlas is available in a computer readable format together
with a IDL program to read and display the data using a widget
interface. The atlas and the programs can be obtained via the World
Wide Web (http://hydra.mpae.gwdg.de/mpae_projects/SUMER/sumer.html)
or by contacting one of the authors.

---------------------------------------------------------
Title: Intercalibration and Co-Registration of the LASCO, UVCS and
SUMER instruments on SOHO
Authors: Michels, J.; Kohl, J. L.; Noci, G.; Antonucci, E.; Tondello,
G.; Huber, M. C. E.; Curdt, W.; Hollandt, J.; Lemaire, P.; Schuhle,
U.; Wilhelm, K.; Korendyke, C.; Moran, T.; Raymond, J. C.; Romoli,
M.; Benna, C.; Ciaravella, A.; Fineschi, S.; Gardner, L. D.; Giordano,
S.; Naletto, G.; Nicolosi, P.; Siegmund, O. H. W.; Spadaro, D.; Smith,
P. L.; Strachan, L.
1996AAS...188.3706M Altcode: 1996BAAS...28..878M
Joint observations of equatorial streamers by three SOHO instruments
have been used for radiometric intercalibration, co-registration and
other spectroscopic comparisons. The results are used to track the
stability of the radiometric calibrations of the Ultraviolet Coronagraph
Spectrometer (UVCS) and the Solar Ultraviolet Measurements of Emitted
Radiation (SUMER) experiment at overlapping wavelenghs. Observations
of equatorial streamers at heliocentric heights from 1.25 to 1.5
R_⊙ are used for the intercalibrations. The results are compared to
pre-launch laboratory calibrations and to observations of stars. The
first stellar observation was for 38 AQI. These UV observations are
compared to coronal green line (Fe XIV) observations obtained with the
Large Angle Spectrometric Coronagraph (LASCO) C1 coronagraph obtained
in the same time frame. Intercomparisons of spectral line profiles
among LASCO, SUMER, and UVCS are also planned. The LASCO research is
supported by NASA Grant NDPR S92835D; the UVCS research is supported by
NASA Contract NAS5-31250 to the Smithsonian Astrophysical Observatory,
by the Italian Space Agency and by Switzerland, and SUMER is financially
supported by BMFT/DARA, CNES, NASA and PRODEX (Swiss Contribution).

---------------------------------------------------------
Title: Solar Coronal Heating - Present Knowledge and Hopes from SOHO
Authors: Lemaire, P.
1996MmSAI..67..979L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: SUMER - Solar Ultraviolet Measurements of Emitted Radiation
Authors: Wilhelm, K.; Curdt, W.; Marsch, E.; Schühle, U.; Lemaire,
P.; Gabriel, A.; Vial, J. -C.; Grewing, M.; Huber, M. C. E.; Jordan,
S. D.; Poland, A. I.; Thomas, R. J.; Kühne, M.; Timothy, J. G.;
Hassler, D. M.; Siegmund, O. H. W.
1995SoPh..162..189W Altcode:
The instrument SUMER - Solar Ultraviolet Measurements of Emitted
Radiation is designed to investigate structures and associated dynamical
processes occurring in the solar atmosphere, from the chromosphere
through the transition region to the inner corona, over a temperature
range from 104 to 2 × 106K and above. These
observations will permit detailed spectroscopic diagnostics of plasma
densities and temperatures in many solar features, and will support
penetrating studies of underlying physical processes, including plasma
flows, turbulence and wave motions, diffusion transport processes,
events associated with solar magnetic activity, atmospheric heating,
and solar wind acceleration in the inner corona. Specifically, SUMER
will measure profiles and intensities of EUV lines; determine Doppler
shifts and line broadenings with high accuracy; provide stigmatic
images of the Sun in the EUV with high spatial, spectral, and temporal
resolution; and obtain monochromatic maps of the full Sun and the inner
corona or selected areas thereof. SUMER will be flown on the Solar
and Heliospheric Observatory (SOHO), scheduled for launch in November,
1995. This paper has been written to familiarize solar physicists with
SUMER and to demonstrate some command procedures for achieving certain
scientific observations.

---------------------------------------------------------
Title: Some design and performance features of SUMER: solar
ultraviolet measurements of emitted radiation
Authors: Wilhelm, Klaus; Curdt, W.; Marsh, E.; Schuehle, Udo H.;
Lemaire, Philippe; Gabriel, Alan H.; Vial, J. -C.; Grewing, Michael;
Huber, Martin C.; Jordan, S. D.; Poland, Arthur I.; Thomas, Roger J.;
Kuehne, Mikhael; Timothy, J. Gethyn; Hassler, Donald M.; Siegmund,
Oswald H.
1995SPIE.2517....2W Altcode:
The instrument SUMER (solar ultraviolet measurements of emitted
radiation) is designed to investigate structures and associated
dynamical processes occurring in the solar atmosphere from the
chromosphere through the transition region to the inner corona, over a
temperature range from 104 to 2 multiplied by 106
K and above. The observations will be performed, on board SOHO (solar
and heliospheric observatory) scheduled for launch in November 1995,
by a scanning, normal-incidence telescope/spectrometer system in
the wavelength range from 500 to 1610 angstrom. Spatial resolution
requirements compatible with the pointing stability of SOHO are less
than 1000 km corresponding to about 1-arcsec angular resolution. Doppler
observations of EUV line shifts and broadenings should permit solar
plasma velocity measurements down to 1 km s-1. We report
here on some specific features of this instrument related to its
pointing as well as its spatial and spectral resolution capabilities.

---------------------------------------------------------
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: High resolution profiles of the MG II H and MG II K lines.
Authors: Staath, E.; Lemaire, P.
1995A&A...295..517S Altcode:
Spectra of the Mg II h and k lines have been recorded by the
balloon-borne telescope spectrograph RASOLBA. The observations have
been made at the center of the solar disk and across the limb with
an angular resolution of 1arcsec along the 30x0.3arcsec^2^ slit and
a spectral resolution of 15pm within the 20nm wavelength range. We
present here the method used to reduce the data and profiles of these
lines at several locations on the solar disk with uncertainties in
the intensity of 16% at sun center. Integral and spectral intensity,
line of sight velocities and limb darkening curve derived from these
spectra are discussed.

---------------------------------------------------------
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: Study of the quiet corona with the SOHO/SUMER spectrometer
Authors: Lemaire, P.; Wilhelm, K.
1994AdSpR..14d.171L Altcode: 1994AdSpR..14..171L
The SOHO/SUMER spectrometer is developed to study the low corona and
chromosphere-corona transition zone. The main scientific objectives are
oriented towards the search of mechanisms producing the coronal heating
and driving the first impulse of the solar wind. The main contribution
will be given by an accurate measurement of line profiles, intensities
and shifts combined with high angular resolution on the solar disk and
above the limb. In this paper, we recall the scientific objectives,
we describe the corresponding instrument capabilities and we show how
the observations can be performed and the kind of data expected. The
complementary role of the SOHO coronal instruments in coordinating
observations to optimize the quality of the data is emphasized.

---------------------------------------------------------
Title: Center-to-limb observations of the lambda 285.2 NM MgI UV
resonance line
Authors: Briand, C.; Lemaire, P.
1994A&A...282..621B Altcode:
We present here new results about the 285.212 nm Mg I resonance
line. The spectra have been obtained from the RASOLBA balloon experiment
of the LPSP launched in 1986 from France. The data have both high
spectral (1.5 pm) and spatial (1 sec) resolution. Spectra of either
the Sun center and the solar limb have been recorded in the 280 nm
range. We paid a careful attention on the spatial evolution of the Mg
I absorption line with the hope to find predicted but not confirmed
emission feature in the central core. The very faint emission detected
at Sun center becomes bright when observed off-limb. We give some
measurements of the Mg I core Doppler shifts.

---------------------------------------------------------
Title: 'SUMER' - Solar Ultraviolet Measurements of Emitted Radiation
Authors: Wilhelm, K.; Curdt, W.; Gabriel, A. H.; Grewing, M.; Huber,
M. C. E.; Jordan, S. D.; Kuhne, M.; Lemaire, P.; Marsch, E.; Poland,
A. I.; Schuhle, U.; Thomas, R. J.; Timothy, J. G.; Vial, J. -C.
1994scs..conf..619W Altcode: 1994IAUCo.144..619W
SUMER is designed for the investigations of plasma flow characteristics,
turbulence and wave motions, plasma densities and temperatures,
structures and events associated with solar magnetic activity in the
chromosphere, the transition zone and the corona. The spatial and
spectral resolution capabilities of the instrument are considered in
some detail, and a new detector concept is introduced.

---------------------------------------------------------
Title: Space instrumentation
Authors: Lemaire, P.
1994LNP...432..297L Altcode: 1994LNPM...11..297L
The capabilities of space instrumentation are in a continuous state
of evolution with the improvement of new techniques such as the
metallic multilayer coatings in the Extreme UltraViolet. After a
brief review of a few of the new techniques that will provide improved
detectors, a survey of current instrumentation is given (Yohkoh, HRTS,
MSSA, NIXT). Several missions are in preparation (SOHO, CORONAS); a
description of the payload capabilities of these is furnished. Finally,
we speculate on the outlook for the new, improved instruments on
future missions.

---------------------------------------------------------
Title: High Resolution Mg II h and Mg II k Line Profiles
Authors: Staath, E.; Lemaire, P.
1994emsp.conf..107S Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Mg I UV and IR Lines of the Quiet Sun
Authors: Briand, C.; Lemaire, P.
1994emsp.conf...53B Altcode:
No abstract at ADS

---------------------------------------------------------
Title: PRISMA: A mission to study interior and surface of stars
Authors: Lemaire, P.
1994esa..conf..540L Altcode: 1994IAUCo.147..540L
No abstract at ADS

---------------------------------------------------------
Title: Prospects for improved instrumentation on future solar space
missions.
Authors: Lemaire, P.
1993ESASP1157...67L Altcode: 1993srfs.book...67L
After a brief summary of the status of space-based instrumentation
at the time when Soho is launched, the areas where improvements
are foreseeable are examined and an overview of the gains that can
be achieved is presented. Special attention is paid to identifying
intrinsic limitations related to classical mountings in the ultraviolet
(UV)/extreme-ultraviolet (EUV) range. Some mountings are then discussed,
with their limitations, in the context of missions already proposed.

---------------------------------------------------------
Title: High Resolution Measurements of the 273-293 nm Solar Spectrum
from a Balloon Instrumentation
Authors: Lemaire, P.; Briand, C.; Staath, E.; Samain, D.
1993BAAS...25.1221L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Une proposition pour le sondage de l'interieur des étoiles
et l'étude de la génération de l'activité (PRISMA).
Authors: Lemaire, P.; Catala, C.
1993JAF....44...35L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Prisma - the First Space Mission to See Inside the Stars
Authors: Appourchaux, T.; Gough, D. O.; Catala, C.; Frandsen, S.;
Frohlich, C.; Hoyng, P.; Jones, A.; Lemaire, P.; Tondello, G.; Weiss,
W. W.
1993ASPC...42..411A Altcode: 1993gong.conf..411A
No abstract at ADS

---------------------------------------------------------
Title: SOHO: a PRISMA precursor
Authors: Lemaire, P.
1993ASPC...40..755L Altcode: 1993ist..proc..755L; 1993IAUCo.137..755L
No abstract at ADS

---------------------------------------------------------
Title: Stellar seismology and activity: the need to go to space
(PRISMA) (invited paper)
Authors: Appourchaux, T.; Catala, C.; Catalano, S.; Frandsen, S.;
Jones, A.; Lemaire, P.; Weiss, W. W.
1993MmSAI..64..415A Altcode:
No abstract at ADS

---------------------------------------------------------
Title: PRISMA: Probing Stars from Core to Corona
Authors: Appourchaux, T.; Catala, C.; Catalano, S.; Fransden, S.;
Fröhlich, C.; Gough, D. O.; Hoyng, P.; Jones, A.; Lemaire, P.;
Tondello, G.; Weiss, W.
1993ASSL..183..505A Altcode: 1993pssc.symp..505A
No abstract at ADS

---------------------------------------------------------
Title: PRISMA: a new space mission for stellar physics.
Authors: Appourchaux, T.; Gough, D.; Hyoyng, P.; Catala, C.; Frandsen,
S.; Froehlich, C.; Jones, A.; Lemaire, P.; Tondello, G.; Weiss, W. W.
1993ASPC...40..812A Altcode: 1993ist..proc..812A; 1993IAUCo.137..812A
This paper mainly focuses on the scientific objectives that can be
achieved with a new space mission of the European Space Agency -
PRISMA (Probing Rotation and Interior of Stars: Microvariability
and Activity). The scientific objectives can be classified into
three areas of interest: (1) Stellar structure and evolution. (2)
Stellar atmospheres and magnetic fields. (3) Stellar dynamics and
stellar dynamos.

---------------------------------------------------------
Title: SUMER: temperatures, densities, and velocities in the outer
solar atmosphere.
Authors: Lemaire, P.; Wilhelm, K.; Axford, W. I.; Curdt, W.; Gabriel,
A. H.; Grewing, M.; Huber, M. C. E.; Jordan, S. D.; Kuehne, M.;
Marsch, E.; Poland, A. I.; Richter, A. K.; Thomas, R. J.; Timothy,
J. G.; Vial, J. C.
1992ESASP.348...13L Altcode: 1992cscl.work...13L
The SUMER instrumentation, that will be mounted on the SOHO spacecraft,
is in development under MPAE leadership. It has some capability
to improve the solar angular resolution and the spectral resolution
already obtained in the far UV to the extreme UV, corresponding to the
temperature range between 104 and a few 106K. The
authors give some insights into the SUMER spectrometer that is developed
to study the dynamics and to infer temperatures and densities of the
low corona and the chromosphere-corona transition zone in using the
50 - 160 nm wavelength range. First, they recall the SUMER scientific
goals and the technics used. Then, after a brief description of the
instrumentation the expected performances are described. The way the
observations can be conducted is emphasized and it is shown how SUMER
is operated in coordination with other SOHO instrumentations and in
cooperation with ground-based observations.

---------------------------------------------------------
Title: "SUMER" - Solar Ultraviolet Measurements of Emitted Radiation.
Authors: Wilhelm, K.; Axford, W. I.; Curdt, W.; Gabriel, A. H.;
Grewing, M.; Huber, M. C. E.; Jordan, S. D.; Kühne, M.; Lemaire, P.;
Marsch, E.; Poland, A. I.; Richter, A. K.; Thomas, R. J.; Timothy,
J. G.; Vial, J. C.
1992eocm.rept..225W Altcode:
The experiment Solar Ultraviolet Measurements of Emitted Radiation
(SUMER) is designed for the investigations of plasma flow
characteristics, turbulence and wave motions, plasma densities
and temperatures, structures and events associated with solar
magnetic activity in the chromosphere, the transition zone and the
corona. Specifically, SUMER will measure profiles and intensities
of extreme ultraviolet (EUV) lines emitted in the solar atmosphere
ranging from the upper chromosphere to the lower corona; determine line
broadenings, spectral positions and Doppler shifts with high accuracy;
provide stigmatic images of selected areas of the Sun in the EUV with
high spatial, temporal and spectral resolution and obtain full images of
the Sun and the inner corona in selectable EUV lines, corresponding to a
temperature range from 104 to more than 1.8×106K.

---------------------------------------------------------
Title: Planned observations at high resolution from space.
Authors: Lemaire, P.; Marsch, E.
1992ESASP.344...15L Altcode: 1992spai.rept...15L
The next generation of solar space experiments is under
development. SOHO with its set of coronal instruments has some
capability to improve the angular resolution already obtained in
the far UV to the extreme UV, corresponding to the temperature
range between 10 and a few 10K. The authors give some insights
into the two spectrometers SUMER and CDS, and the extreme UV imager
EIT. SUMER is developed to study the dynamics of the low corona and the
chromosphere-corona transition zone in using the 50 - 160 nm wavelength
range. CDS is a spectrometer built to observe the highest part of the
chromosphere-corona transition zone up to the high corona of several
millions of degrees in using the 15 - 80 nm wavelength range. EIT is
a multi-wavelength imager that will provide either full or partial
solar images in upper chromospheric and coronal lines.

---------------------------------------------------------
Title: SUMER - Solar ultraviolet measurements of emitted radiation
Authors: Wilhelm, K.; Axford, W. I.; Gurdt, W.; Marsch, E.; Richter,
A. K.; Grewing, M.; Gabriel, A. H.; Lemaire, P.; Vial, J. -C.; Huber,
M. C. E.
1992sws..coll..129W Altcode:
The SUMER (solar ultraviolet measurements of emitted radiation)
experiment is described. It will study flows, turbulent motions, waves,
temperatures and densities of the plasma in the upper atmosphere of
the Sun. Structures and events associated with solar magnetic activity
will be observed on various spatial and temporal scales. This will
contribute to the understanding of coronal heating processes and the
solar wind expansion. The instrument will take images of the Sun in EUV
(extreme ultraviolet) light with high resolution in space, wavelength
and time. The spatial resolution and spectral resolving power of the
instrument are described. Spectral shifts can be determined with
subpixel accuracy. The wavelength range extends from 500 to 1600
angstroms. The integration time can be as short as one second. Line
profiles, shifts and broadenings are studied. Ratios of temperature
and density sensitive EUV emission lines are established.

---------------------------------------------------------
Title: PRISMA: A Space Facility for Studying the Rotation; Interior
of Stars
Authors: Lemaire, P.; Appourchaux, T.; Jones, A.; Catala, C.; Catalano,
S.; Frandsen, S.; Weiss, W.
1992ASPC...26..643L Altcode: 1992csss....7..643L
No abstract at ADS

---------------------------------------------------------
Title: Ultraviolet conical diffraction: a near-stigmatic tandem
grating mounting spectrometer
Authors: Lemaire, Philippe
1991ApOpt..30.1294L Altcode:
A tandem conical diffraction mount for UV and EUV operation is
proposed which improves spectral resolution and virtually eliminates
monochromatic slit-image rotation, thereby improving spectral image
quality. Attention is given to the illustrative example of a complete
solar telescope-spectrometer instrumentation; a comparison is made of
the spectral and angular resolution qualities and lower-efficiency
limits of the mountings with other, recently developed solar
instrumentations for the 30-135 nm bandpass. As expected, however,
the equivalent efficiency of the present instrument is lower than that
of the alternatives with which it is compared.

---------------------------------------------------------
Title: A solar interferometric mission for ultrahigh resolution
imaging and spectroscopy: SIMURIS
Authors: Damé, L.; Acton, L.; Bruner, M.; Connes, P.; Cornwell, T.;
Foing, B. H.; Heyvaerts, J.; Lemaire, P.; Martić, M.; Muller, R.;
Porteneuve, J.; Roca Cortés, T.; Riehl, J.; Rutten, R.; Séchaud,
M.; Smith, P.; Thorne, A. P.; Title, A. M.; Vial, J. -C.; Visser,
H.; Weigelt, G.
1991AdSpR..11a.383D Altcode: 1991AdSpR..11..383D
SIMURIS is an interferometric investigation of the very fine structure
of the solar atmosphere from the photosphere to the corona. It was
proposed to ESA /1/, November 30 1989, for the Next Medium Size
Mission - M2, and accepted in February 1990 for an Assessment Study
in the context of the Space Station. The main scientific objectives
will be outlined, and the ambitious model payload featuring the Solar
Ultraviolet Network (SUN), a 2 m long monolithic array of 4 telescopes
of Ø20 cm, and the Imaging Fourier Transform Spectrometer (IFTS),
an UV and Visible Imaging Fourier Transform Spectrometer coupled to
a Ø40 cm Gregory, described.

---------------------------------------------------------
Title: Solar physics at ultrahigh resolution from the space station
with the Solar Ultraviolet Network (SUN)
Authors: Damé, L.; Acton, L.; Bruner, M.; Connes, P.; Cornwell,
T.; Foing, B.; Heyvaerts, J.; Lemaire, P.; Martić, M.; Muller, R.;
Roca Cortés, T.; Riehl, J.; Rutten, R.; Title, A. M.; Vial, J. -C.;
Visser, H.; Weigelt, G.
1991AdSpR..11e.267D Altcode: 1991AdSpR..11..267D
The SUN experiment is a UV and visible Space Interferometer aimed at
ultra-high resolution in the solar atmosphere. It has been proposed
to ESA as part of the SIMURIS Mission Proposal which has recently
been accepted for an Assessment Study in the framework of the
Space Station. The 4 × 20 cm telescopes of the SUN linear array are
non-redundantly placed to cover a 2 m baseline, and the instrument makes
full use of stabilized interferometry potential, the 4 telescopes being
co-aligned and co-phased on a reference field on the sun. After a brief
outline of the scientific objectives, the concept of the instrument
is described, and its image reconstruction potential is illustrated.

---------------------------------------------------------
Title: Prisma - a Space Facility for Studying Rotation and Activity
Authors: Lemaire, P.; Appourchaux, T.; Catala, C.; Catalano, S.;
Frandsen, S.; Jones, A.; Weiss, W.
1991ASIC..340..397L Altcode: 1991amey.conf..397L
No abstract at ADS

---------------------------------------------------------
Title: ESO observations with the IAP/IAS Ca II K special spectrometer
during the MUSICOS 89 campaign.
Authors: Char, S.; Foing, B.; Lemaire, P.; Lagrange, A. M.; Beust,
H.; Vidal Madjar, A.; Vitry, R.; Zimmerman, J. P.
1991musi.work...69C Altcode:
HR 1099, a highly active RS CVn star was monitored in the chromospheric
Ca II K line during the Musicos campaign. The authors used a special
spectrometer developed to monitoring variations of the Ca II lines on
stars (circumstellar absorption for β Pictoris and emissive features
on stars showing solar-like magnetic activity such as the RS CVn and
late type stars). They describe the characteristics of the instrument
and show a sample of obtained spectra for HR 1099.

---------------------------------------------------------
Title: SOHO-A high resolution solar physics mission
Authors: Lemaire, P.
1991AdSpR..11e.169L Altcode: 1991AdSpR..11..169L
SOHO (SOlar and Heliospheric Observatory) is a joint ESA/NASA mission
within the ISTP-International Solar Terrestrial Program. The satellite,
with a pointing stability of 1 arcsecond, will be launched in 1995 to
the L1 Lagrangian point between Sun and Earth. The selected
payload, in accordance with the scientific objectives of the mission,
is being developed: -to obtain long and uninterrupted series of
solar oscillations measurements either in flux or in velocity in order
to sound the solar interior using high resolution in the frequency
domain. -to probe the upper solar atmosphere with high resolution
UV/EUV imager/spectrometers and UV/visible coronagraphs and photometers
in order to bring new constraints on the coronal heating, to identify
the source and accelerating mechanisms of the solar wind. -to
measure in-situ the solar wind flow in front of the Earth and so,
establish the link between the Sun and the near-Earth environment.

---------------------------------------------------------
Title: Sensitivity changes in the CNRS ultraviolet spectrometer
aboard OSO-8.
Authors: Lemaire, P.
1991ESAJ...15..237L Altcode:
The CNRS solar ultraviolet multichannel experiment on the OSO-8
spacecraft operated from Jun 1975 to Sep 1978. At the beginning
of orbital operations, a strong sensitivity change appeared in the
ultraviolet channels. After a brief description of the instrumentation,
the main optical parameters and the principle of the experiment,
and the integration procedures and preflight calibration control,
the in-orbit measurements of sensitivity are presented and the results
are critically discussed.

---------------------------------------------------------
Title: Possible observations of coronal heating and solar/stellar
winds with space instruments.
Authors: Lemaire, P.
1991cwlt.conf...33L Altcode:
The need for new observations of solar/stellar coronae and winds
is clearly established and requires dedicated instrumentation in
coordinated missions. The objectives and the expected performance of
the SOHO coronal payload are described on one hand. On the other hand,
some insight into the stellar PRISMA mission in study at ESA are given.

---------------------------------------------------------
Title: Prisma-probing rotation and interior of stars: Microvariability
and activity
Authors: Lemaire, P.; Appourchaux, T.; Catala, C.; Catalano, S.;
Frandsen, S.; Jones, A.; Weiss, W.
1991AdSpR..11d.141L Altcode: 1991AdSpR..11..141L
The measurement of frequencies, amplitudes and lifetimes of solar
oscillations has proven to be a very powerful tool to sound the
properties of the solar internal structure. Combined with observations
of emerging solar magnetic field parameters of the solar internal
structure and dynamo can be inferred. The same techniques may be
used to sound stellar interiors: asteroseismology and observation
of magnetic activity (emerging magnetic fields). The observation of
photometric fluctuations down to micromagnitudes on stars along or
near the main sequence when complemented with measurements of activity
levels will provide a wealth of information on the internal structure
and rotation rates, and its evolutions with age. The PRISMA mission
is an ESA Assessment Study currently underway. We present here the
scientific objectives of the mission, the measurements to be made, the
techniques to be used, and the main characteristics of a model payload.

---------------------------------------------------------
Title: The imaging fourier transform spectrometer for the SIMURIS
mission
Authors: Foing, B. H.; Dame, L.; Thorne, A. P.; Lemaire, P.
1991AdSpR..11a.387F Altcode: 1991AdSpR..11..387F
The Solar Interferometric Mission for Ultrahigh Resolution Imaging and
Spectroscopy (SIMURIS) is an interferometric investigation in space
at ultraviolet and visible wavelengths aimed at reconnaissance of
solar features at angular scales from 0.3 to 0.01 arcsec. The Imaging
Fourier Transform Spectrometer (IFTS) is, with the Solar Ultraviolet
Network (SUN), one of the core instruments of the proposed SIMURIS
mission. It consists of a 40 cm Gregory telescope feeding a double
grating pre-dispersive spectrometer before entering a Fourier transform
spectrometer for a field of 10 × 10 arcsec2 at 0.3 arcsec
resolution. The SIMURIS/IFTS requires upgrading of existing FTS down
to 120 nm, with imaging capabilities. For the IFTS imaging a detector
with fast readout must be used. There are also demanding constraints
on the real time processing, and the subsequent important data rate,
and requirements on an upgraded instrument pointing system (IPS),
within the resources and capabilities of the Space Station.

---------------------------------------------------------
Title: Experimental study of the role of plasma polarization on line
shape in dense laboratory plasmas.
Authors: Jamelot, G.; Jaegle, P.; Lemaire, P.; Carillon, A.
1990JQSRT..44...71J Altcode:
This paper presents an experimental study of the spectral line profiles
emitted by multicharged ions in dense laser-produced plasmas. The time
and/or space integrated spectra of the Lyman series of H-like lithium
show a strong red asymmetry and, in some cases, a red shift of the top
of the lines. It is shown that such profiles have to be interpreted
as due to space and time integration of mostly symmetric profiles,
which are red shifted by an amount that depends on the emitting plasma
zone. Theoretically calculated profiles show the role, in the observed
profiles, of the plasma polarization shift due to the penetration of
atomic orbits by the plasma free electrons.

---------------------------------------------------------
Title: Fine structure observation in a solar prominence
Authors: Lemaire, P.; Samain, D.; Vial, J. C.
1990AdSpR..10i.191L Altcode: 1990AdSpR..10..191L
The high resolution balloon spectrograph (RASOLBA) has obtained
ultraviolet prominence spectra during its September 19th, 1986,
flight. The high resolution spectra (one arcsecond along the
30 arcseconds spectrograph slit length, and 0.0015 nm spectral
resolution within the 20 nm wavelength band) have been recorded on
film. The wavelength band was centered on the Mgll h and k (279.6
nm and 280.3 nm) resonance doublet lines inside the cross-dispersion
echelle spectrograph. The analysis of the prominence spectra shows
evidence of sheared velocities (up to 20 km/s) which very within few
arcseconds with the distance above the limb. This shear may appear
inside magnetic loops confining the prominence material. We present
the observations and a preliminary analysis of the data.

---------------------------------------------------------
Title: 8-25 eV high resolution solar spectrometer
Authors: Lemaire, Philippe; Wilhelm, Klaus
1989SPIE.1140..522L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Solar Ultraviolet Network: an interferometric investigation
of the fundamental solar astrophysical scales
Authors: Dame, Luc; Moreau, Bernard G.; Cornwell, Timothy J.;
Visser, H.; Title, Alan M.; Acton, Loren W.; Aime, Claude; Braam,
Bart M.; Bruner, Marilyn E.; Connes, Pierre; Faucherre, Michel; Foing,
B. H.; Haisch, Bernhard M.; Hoekstra, Roel; Heyvaerts, Jean; Jalin,
Rene; Lemaire, Philippe; Martic, Milena; Muller, R.; Noens, J. C.;
Porteneuve, Jacques; Schulz-Luepertz, E.; von der Luehe, Oskar
1989SPIE.1130..126D Altcode:
The Solar UV Network (SUN) presently proposed is an interferometric
system, based on the principles of stabilized interferometry, which
will be capable of solar observations with spatial resolutions better
than 0.013 arcsec. SUN will consist of four 20-cm diameter telescopes
aligned nonredundantly on a 2-m baseline. SUN is judged to be ideally
deployable by the NASA Space Station, if implemented on a pointing
platform whose performance is of the order of the Instrument Pointing
System flown on Spacelab 2. The compact, nonredundant configuration of
SUN's telescopes will allow high-resolution imaging of a 2 x 2 arcsec
field on the solar disk.

---------------------------------------------------------
Title: High resolution observations of the solar UV spectrum from
balloon
Authors: Lemaire, P.; Samain, D.
1989hsrs.conf..551L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Use of thinned backside illuminated CCD from the extreme
ultraviolet to the soft ultraviolet
Authors: Hochedez, Jean-Francois E.; Lemaire, Philippe; Delaboudiniere,
Jean-Pierre; Cougrand, Bernard; Barba, Julien
1989SPIE.1070...53H Altcode:
No abstract at ADS

---------------------------------------------------------
Title: SUMER - Solar ultraviolet measurements of emitted radiation.
Authors: Curdt, W.; Wilhelm, K.; Axford, W. I.; Marsch, E.; Richter,
A. K.; Gabriel, A. H.; Lemaire, P.; Vial, J. -C.; Grewing, M.; Huber,
M. C. E.; Jordan, S. D.; Poland, A. I.; Thomas, R. J.; Timothy, J. G.
1989AGAb....2...14C Altcode: 1989amt..conf...14C
No abstract at ADS

---------------------------------------------------------
Title: The diagnostic and modelling of the solar atmosphere through
non-LTE radiative transfer: some results and prospects.
Authors: Gouttebroze, Pierre; Vial, Jean-Claude; Lemaire, P.
1989mse..proc..245G Altcode:
The authors describe new results from non-LTE radiative transfer
calculations for solar UV continua and line profiles. The new non-LTE
codes include partial frequency redistribution in the lines, moving
atmospheres with differential velocities, and can treat finite objects
with external irradiation (loops, prominences). Selected examples are
given for: (1) a static atmosphere (plage); (2) a moving atmosphere
(waves); and (3) free standing slabs (prominences).

---------------------------------------------------------
Title: SUMER: Solar Ultraviolet Measurements of Emitted Radiation
Authors: Wilhelm, K.; Axford, W. I.; Curdt, W.; Gabriel, A. H.;
Grewing, M.; Huber, M. C. E.; Jordan, M. C. E.; Lemaire, P.; Marsch,
E.; Poland, A. I.
1988sohi.rept...31W Altcode:
The SUMER (solar ultraviolet measurements of emitted radiation)
experiment is described. It will study flows, turbulent motions, waves,
temperatures and densities of the plasma in the upper atmosphere of
the Sun. Structures and events associated with solar magnetic activity
will be observed on various spatial and temporal scales. This will
contribute to the understanding of coronal heating processes and the
solar wind expansion. The instrument will take images of the Sun in EUV
(extreme ultra violet) light with high resolution in space, wavelength
and time. The spatial resolution and spectral resolving power of the
instrument are described. Spectral shifts can be determined with
subpixel accuracy. The wavelength range extends from 500 to 1600
angstroms. The integration time can be as short as one second. Line
profiles, shifts and broadenings are studied. Ratios of temperature
and density sensitive EUV emission lines are established.

---------------------------------------------------------
Title: Needs for high resolution spectroscopy in ultraviolet solar
physics.
Authors: Lemaire, P.
1988JPhys..49..335L Altcode: 1988IAUCo.102..335L
The study of the solar atmosphere (from 5000K to few millions K)
is made through ultraviolet lines emitted by ionized elements. The
understanding of the heating processes, the solar wind generation
and its acceleration mechanisms require a global and detailed mass
and energy budget of the atmosphere. The new ultraviolet spectrometers
proposed on SOHO satellite are able to combine enough angular, spectral
and temporal resolutions to establish this budget.

---------------------------------------------------------
Title: Prospect for Stellar Seismology on Board an Interplanetary
Spacecraft
Authors: Praderie, F.; Mangeney, A.; Lemaire, P.; Puget, P.;
Bisnovatyi-Kogan, G. S.
1988IAUS..123..549P Altcode:
The authors describe a stellar seismology photometric experiment which
they have proposed to embark on-board the interplanetary vehicles
belonging to the VESTA mission (France-USSR mission towards Mars and
the asteroids belt, to be launched about 1994). The objective is to
use the cruise time to obtain long, uninterrupted observations of
the white light fluctuations in a few late-type stars, with a view to
the detection of global non-radial modes at the level 10-5
to 10-6mag.

---------------------------------------------------------
Title: Solar Ultraviolet Spectrum Obtained from a Balloon Gondola
Authors: Samain, D.; Lemaire, P.
1987ESASP.270..347S Altcode: 1987erbp.symp..347S
A new flight of the L.P.S.P. balloon experiment on September 19, 1986
has permitted the recording of high resolution photographic spectra in
the 2800 Å channel (1 arcsec and 15 mÅ). Several time sequences at Sun
center, limb, intermediate location (μ = 0.5) and on a prominence have
been performed; some of these results are presented. Data reduction
of the high spectral resolution spectra recorded in 1982 has been
completed for the region 1950-2000 Å, in which many features have
been measured and tabulated; one of these detailed tracings is given
and some results on wavelength shifts analysed.

---------------------------------------------------------
Title: "Underluminous" Lyman-alpha Emission Associated with
Active-Region Magnetic Canopy
Authors: Jones, H. P.; Skumanich, A.; Lemaire, P.
1987BAAS...19..930J Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Physical structure and diagnostics of solar active regions
deduced from optical, visible and UV observations.
Authors: Lemaire, P.
1987PAICz..66..185L Altcode: 1987eram....1..185L
This paper reviews the status of our knowledge of the physical
properties of active regions in the photosphere, chromosphere and
transition zone, as inferred from observations.

---------------------------------------------------------
Title: Analysis of solar and stellar chromospheric calcium and
magnesium lines
Authors: Lemaire, P.; Simon, G.; Mangeney, A.; Clary, O.; Praderie,
F.; Mouradian, Z.
1986AdSpR...6h..73L Altcode: 1986AdSpR...6R..73L
Using a combination of ground-based and satellite observations of
the Sun, we determine several parameters of CaII H, K and MgII h,
k chromospheric lines. From simple chromospheric models (similar to
those proposed by T. Ayres) we establish semi-empirical laws obeyed by
some of these parameters. This allows us to deduce some constraints
on the chromospheric heating rate. These results are then applied to
observed spectra of main sequence stars.

---------------------------------------------------------
Title: Balloon-Borne Ultraviolet Solar Telescope and High Resolution
Echelle Spectrograph - Instrumentation and First Results
Authors: Samain, D.; Lemaire, P.
1985Ap&SS.115..227S Altcode:
A description of the LPSP balloon-borne telescope — spectrograph
combination is given. The payload comprises a one-axis stabilized
platform carrying a two-axes equatorial pointing system; the
instrumentation directed towards the Sun is a 300 mm telescope coupled
with an echelle spectrograph and a slit jaw camera. The scientific
objective of the experimental set-up is to observe spatial, spectral,
and temporal variations of fine structures of the solar atmosphere,
using ballon ultraviolet windows between 190 and 300 nm, with very
high angular and spectral resolutions (0.5 arc sec and 1 pm). In the
configuration of the first flight which successfully took place on 1
October, 1982 from Aire-sur'l'Adour (Landes), many stigmatic spectra
of the Sun were recorded in the 190 213 and 272 293 nm ranges, with
an angular resolution of 4 arc sec and a spectral resolution of 1.5
to 2 pm.

---------------------------------------------------------
Title: Solar High Resolution Balloon Spectra Obtained in the 190-300
nm Wavelength Band
Authors: Samain, D.; Lemaire, P.
1985LNP...233..123S Altcode: 1985hrsp.proc..123S
A balloon gondola with a solar telescope spectrograph has been
launched from Aire/Adour (France) October 1, 1982. High quality
spectra with a spectral resolution better than 1.5 pm and with a 4 -
5 arcseconds angular resolution have been recorded in the atmospheric
window domains: 195 - 212 nm and 272 - 292 nm. Results from this first
flight are discussed.

---------------------------------------------------------
Title: Solar Physics from Space
Authors: Lemaire, P.
1985ESASP.229..139L Altcode: 1985erbp.symp..139L
During the last years, as a result of a continuous effort, new insights
have been given on the physics of solar phenomena. Observational
data coming from satellites, rockets and balloon experiments have
been combined with ground based observations and have stimulated new
theoretical explanations. During the same period, global characteristics
of the sun (such as activity and magnetic fields, corona and solar
winds, oscillations) have been recognized as a feature of stars during
a period of their evolution. Unsatisfactory detailed mechanisms to
explain these characteristics are under study and to select and improve
theory new types of observations are required.

---------------------------------------------------------
Title: Solar high resolution balloon spectra obtained in the 190-300
nm wavelength band
Authors: Lemaire, P.; Samain, D.
1984AdSpR...4h..37L Altcode: 1984AdSpR...4...37L
To obtain solar high-resolution balloon spectra in the 190-300
nm wavelength range outside of the strong absorption ozone
band, a new solar instrumentation and an equatorial mounting
platform are developed. The instrumentation, which consists of a
telescope-spectrograph combination, and its characteristics are
described. Observations are made at an altitude of 38 km and two
sequences of spectra are taken near sun center, one on a supergranular
cell and the other one over an active network. The spectra recorded
during the flight show an intensity variation related to the wavelength
dependance of atmospheric transmission. The results obtained in two
wavelength domains (190-210 nm and 272-283 nm) during the first balloon
flight are presented and discussed. The spectral resolution is found
to be better than 2 pm in the 200 nm range and better than 1.5 pm in
the 280 nm range; and the angular resolution is found to be about
5 arcsec. Calibration in intensity is made by comparison to rocket
spectra. Stigmatic line profiles illustrate the results.

---------------------------------------------------------
Title: A Stabilized Platform Carrying One or Two Telescopes
Authors: Lemaire, P.
1984srps.conf..177L Altcode:
The study of a mission dedicated to stellar variability and activity
leads to two specific instrumentations: a white light photometer and
an ultraviolet multichannel spectrometer. Although it is possible to
combine the two objectives in one instrumentation, for the optimization
of the mission two separate instruments will give the best scientific
return. The optical schemes presented here are not intended to provide
the ultimate design; but they give the sensitivity and resolution
expected from classical instrumentation and are useful to define a
preliminary mission.

---------------------------------------------------------
Title: Simultaneous H and K Ca ii, h and k Mg ii, Lα and Lβ
H i profiles of the April 15, 1978 solar flare observed with the
OSO-8/L.P.S.P. experiment
Authors: Lemaire, P.; Choucq-Bruston, M.; Vial, J. -C.
1984SoPh...90...63L Altcode:
Solar flare observations have been performed with the multichannel
L.P.S.P. experiment on board OSO-8 NASA Satellite. Simultaneous H and K
CaII, h and k MgII, Lα and Lβ HI profiles have been recorded on the
plage just before the flare, during the flare onset and relaxation
phases. The different behaviour of line profiles and intensities
during the flare is evidenced and indicates a downward propagation
with relaxation times increasing from the upper part to the lower part
of the chromosphere related to line formation processes. Using the Hɛ
observed profile, an upper limit of 8 × 1013 cm-3
is derived for the electron density.

---------------------------------------------------------
Title: Simultaneous H and K CAII H and K MGII L-Alpha L-Beta HI
Profiles of a Solar Flare Observed with OSO-8 L.P.S.P. Spectrometer
Authors: Lemaire, P.; Choucq-Bruston, M.; Vial, J. C.
1984apoa.conf..266L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Increasing solar chromosphere line intensities with solar
activity
Authors: Lemaire, P.
1984AdSpR...4h..29L Altcode: 1984AdSpR...4...29L
Solar activity is characterized either by sunspots or by
plages. Sunspots are detected in the continuum visible as dark
features. Plages are defined in chromospheric lines such as CaII H and
K or HI H-alpha by brightness enhancements. Chromospheric activity
is an important parameter for the knowledge of the equilibrium
input and output energy of the outer solar atmosphere. The
OSO-8/L.P.S.P.-multichannel experiment has recorded simultaneous
chromospheric profiles in H and K CaII, h and k MgII, L-alpha and
L-beta HI lines. Those lines are formed from the temperature minimum
(4200 K) to the higher part of the chromosphere (30000 K). A data set
recorded over a quiet sun, plage, penumbra, and filament is presented
hereafter. The observations, data reduction, and calibration are
described. Then a comparison between line intensities is made and
results are discussed.

---------------------------------------------------------
Title: On the PSIVA approach to stellar seismology and activity
from space
Authors: Praderie, F.; Mangeney, A.; Lemaire, P.
1984AdSpR...4h.163P Altcode: 1984AdSpR...4..163P
We propose a modest payload, using a simple telescope and well known
technology, with the aim of placing the probing of stellar interiors
on an experimental basis. Indeed, a number of physical processes,
the seat of which is in stellar interiors and which are of basic
importance for physics and astrophysics, have not yet been mastered :
convection, differential rotation, dynamo generation of magnetic fields,
etc...Collecting significant observations is of prime importance to
elucidate those phenomena. Two types of observations are sought
: -The pulsation spectrum (detection of microvariability at the
level of that found in the Sun, i.e. 10-6 mag). -The
active phenomena of magnetic origin in the atmosphere, at various
altitudes simultaneously, for a representative sample of stars over
the Hertzsprung-Russell diagram. The basic requirements are long
series of continuous and homogeneous observations with high photometric
accuracy -in white light -in four spectroscopic indices,
three of them being in the UV range (CaII λ 3933 A, MgII λ 2800 A,
HeII λ 1640 A, CIV λ 1550 A). The motives to perform these
observations from space will be analyzed.

---------------------------------------------------------
Title: H and K Ca II plage profiles obtained with a Fourier Transform
Spectrometer
Authors: Lemaire, P.
1983SoPh...88...31L Altcode:
H and K Ca II plage profiles have been obtained with the Kitt Peak
Fourier Transform Spectrometer. A good correlation exists between the
K1 minimum separation and the K index. Correlation between
CN band index and magnetic field is also evidenced, but, probably due
to the poor statistic, no clear correlation appears between K index
and magnetic field.

---------------------------------------------------------
Title: Magnesium II line formation - The contribution of high atomic
levels to the resonance lines
Authors: Lemaire, P.; Gouttebroze, P.
1983A&A...125..241L Altcode:
An evaluation of the solar and stellar atmospheric modeling consequences
of the use of different Mg(+) ion atomic models in line profile
computations has determined that the h and k line cores appear to
be almost insensitive to the number of levels used in the profile
computations. A careful treatment of the blended resonance doublet wings
appears to be necessary, however, for atmospheric diagnostics using
the subordinate 279.1 and 179.9 lines. The cores and near wings of h
and k are strongly sensitive to the atmospheric model, from the higher
part of the photosphere to the upper part of the chromospheric plateau.

---------------------------------------------------------
Title: A high-resolution ultraviolet solar telescope/spectrograph
mounted on an equatorial balloon platform
Authors: Samain, D.; Lemaire, P.
1983ESASP.183..401S Altcode:
A balloon-borne 30 cm telescope-spectrograph combination was built
to observe fine structures of the solar atmosphere with very high
spectral and angular resolution in two atmospheric windows: 2700 to
2950 A and 1900 to 2300 A. Solar spectra with spectral resolution of
15 mA and angular resolution of 4 arcsec were recorded.

---------------------------------------------------------
Title: L'utilisation des ballons stratosphériques en astronomie:
la réalisation de nacelles pointées sur le soleil pour l'étude
du spectre ultraviolet solaire.
Authors: Lemaire, P.
1983LAstr..97..211L Altcode:
The design and performance characteristics of sun-pointing
nacelles for high altitude balloon observation of solar emissions is
described. Solar UV astronomy at altitudes above 30 km allows detection
of spectral lines below 3000 A otherwise absorbed by the atmosphere,
particularly by ozone. The resonance doublet of Mg is observable,
providing information on the mean chromospheric behavior. Emissions
below 2080 A are accessible, and originate in the thin atmospheric
layer around the sun. An equatorial nacelle allows the sun-pointing
fixation of the instruments. Meridional acquisition is achieved by
means of a magnetometer and a reaction wheel, which decouples the
nacelle from motions of the tether connecting the nacelle to the
balloon. Narrow-field sun sensors with successively higher resolution
within a series produce stabilization on the solar disk. The first
flight of the nacelle was in 1982, when a pointing accuracy of 4 deg
was demonstrated while using a spectrograph.

---------------------------------------------------------
Title: Physical properties of the solar chromosphere deduced from
optically thick lines. I - Observations, data reduction, and modelling
of an average plage
Authors: Lemaire, P.; Gouttebroze, P.; Vial, J. C.; Artzner, G. E.
1981A&A...103..160L Altcode:
Simultaneous Ca II H and K, Mg II h and k, and H I Lyman-alpha and
Lyman-beta profiles have been recorded by the OSO-8/LPSP spectrometer on
a quiet sun area and a part of plage, McMath 13738. After data reduction
and filtering, a full set of calibrated profiles is obtained. Using
a code developed at LPSP (Gouttebroze et al., 1978), profiles
computed from VAL III model C (Vernazza et al., 1981) are compared
to observations. A specific plage model has been computed to fit the
observed profiles. This model reproduces successfully Ca II H and K,
and H I Lyman-alpha and Lyman-beta, but partly fails with Mg II h and
k. Atmospheric inhomogeneities and dynamical effects may contribute to
this discrepancy, and it is proposed that the level number entering
in the Mg II computation be increased to take account of a likely
fluorescence induced by the H I Lyman-beta radiation field.

---------------------------------------------------------
Title: Absorption feature observed on the H Lyman-alpha solar line -
an interpretation
Authors: Artzner, G.; Cazes, S.; Emerich, C.; Vial, J. C.; Lemaire, P.
1981A&A...100..205A Altcode:
A narrow absorption feature on the red part of the solar H Lyman-alpha
profile has been observed by two instruments in 1975 and attributed
to atomic hydrogen of the nearby interplanetary gas. This hypothesis
implies that the absorption feature shifts with the position of the
earth on its orbit. New measurements above active regions at other
seasons rule out this hypothesis. On the other hand, appropriate
laboratory calibrations indicate that the absorption feature is likely
due to a ghost image of the geocoronal absorption.

---------------------------------------------------------
Title: OSO-8 Observations of CAII H and K MGII H and K Lyman-Alpha
and Lyman-Beta above a Sunspot
Authors: Kneer, F.; Scharmer, G.; Mattig, W.; Wyller, A.; Artzner,
G.; Lemaire, P.; Vial, J. C.
1981SoPh...69..289K Altcode:
Observations with the French (L.P.S.P.) experiment on board OSO-8 of
a sunspot and nearby plage region are described. The behaviour of the
emission cores of the Ca II H and K and Mg II h and k resonance lines is
very similar and the correspondence in intensity between the four lines
persists in all observed features. In contrast, the Lyman lines show
little correlation with the other lines. Their emission regions appear
broader in the spectroheliograms than the underlying sunspot structure
and must not necessarily possess a counterpart in lower layers. From
the central intensity of Lα above the umbra an electron density of
4.3 × 1010 cm-3 ≲ne*
≲2.3 × 1011 cm-3 at 20 000 K is estimated.

---------------------------------------------------------
Title: Solar H I LY alpha far wing measurement
Authors: Jouchoux, A.; Vial, J. C.; Artzner, G. E.; Gouttebroze, P.;
Lemaire, P.
1981A&A....93..415J Altcode:
High spectral resolution photoelectric observations of the solar H I
Ly alpha far wing are presented. Measurements above active regions and
quiet sun center are compared to photographic observations of Basri
et al. (1979).

---------------------------------------------------------
Title: Haute résolution U.V. solaire OSO8 - LPSP
Authors: Lemaire, P.
1981hrse.conf..197L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Haute résolution U.V. solaire HRTS - NRL
Authors: Lemaire, P.
1981hrse.conf..195L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: On VI (λ = 1032 Å) profiles in and above an active region
prominence, compared to quiet Sun center and limb profiles
Authors: Vial, J. C.; Lemaire, P.; Artzner, G.; Gouttebroze, P.
1980SoPh...68..187V Altcode:
O VI (λ = 1032 Å) profiles have been measured in and above a filament
at the limb, previously analyzed in H I, Mg II, Ca II resonance lines
(Vial et al., 1979). They are compared to profiles measured at the
quiet Sun center and at the quiet Sun limb.

---------------------------------------------------------
Title: Profiles of H I (Lalpha ), Mg II (h and k), Ca II (H and K)
lines of an active filament at the limb, with the LPSP instrument
aboard the OSO-8 satellite.
Authors: Vial, J. C.; Gouttebroze, P.; Artzner, G.; Lemaire, P.
1979SoPh...61...39V Altcode:
We scanned the H I Lα, Mg II h and k, Ca II K and H lines
simultaneously with the LPSP instrument on OSO-8, to investigate the low
and moderate temperature regions of an `active region filament'. The
Lα line is not reversed except for the innermost position in the
prominence. Intensity (k/h), (K/H) ratios are respectively 2 and 1.1,
indicating that the Mg II lines are optically thin, and that Ca II
K is saturated, although not clearly reversed. The results obtained
during the second sequence of observations (K saturated before Lα
for example) indicate that within the size of the slit (1″ × 10″)
we are not observing the same emitting features in the different lines.

---------------------------------------------------------
Title: LY α and β of hi, H and K of MG ii, H and K of CA II Profiles
of a Quiescent Prominence Obtained with the LPSP Instrument of OSO-8.
Authors: Vial, J. C.; Lemaire, P.; Gouttebroze, P.
1979phsp.coll...52V Altcode: 1979IAUCo..44...52V
No abstract at ADS

---------------------------------------------------------
Title: Solar optical telescope (SOT).
Authors: Dunn, R. B.; Fisher, R.; Harvey, J.; Lemaire, P.; Milkey,
R.; Smithson, R.; Beckers, J.; Mehltretter, J. P.; Zirin, H.
1979MmArc.106..135D Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Science opportunities with the SOT.
Authors: Dunn, R. B.; Fisher, R.; Harvey, J.; Lemaire, P.; Milkey,
R.; Smithson, R.; Beckers, J.; Mehltretter, J. P.; Zirin, H.
1979MmArc.106..245D Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Profiles of H i (Lyα), MG II (h and K), CA II (h and k)
Lines in an Active Filament at the Limb, Observed with the LPSP
Instrument Onboard the OSO-8 Satellite.
Authors: Vial, J. C.; Gouttebroze, P.; Artzner, G.; Lemaire, P.
1979phsp.coll..250V Altcode: 1979IAUCo..44..250V
No abstract at ADS

---------------------------------------------------------
Title: The solar hydrogen Lyman-beta and Lyman-alpha lines: disk
center observations from OSO 8 compared with theoretical profiles.
Authors: Gouttebroze, P.; Lemaire, P.; Vial, J. C.; Artzner, G.
1978ApJ...225..655G Altcode:
The solar La and Lfl lines of hydrogen have been measured at the center
of the disk with the LPSP spectrometer aboard OSO 8. These line profiles
are compared with theoretical profiles obtained with different solar
atmospheric models, assuming either complete or partial frequency
redistribution in scattering. The assumption of microturbulence for
the velocity fields appears insufficient to account for the profiles
of the line cores; better results are obtained with a blend of micro-
and macroturbulence, which shows the need of a generalized treatment of
the turbulent motions in the formation of these lines. If the effects
of partial redistribution are taken into account, a good fit of the
line wings requires higher temperatures, in the region under the
plateau, than in the reference atmospheric model of Vernazza, Avrett,
and Loeser. Subject headings: line formation - line profiles - Sun:
chromosphere - Sun: spectra - ultraviolet: spectra

---------------------------------------------------------
Title: Simultaneous time-resolved observations of the H Lalpha ,
Mg k 2795 Å, and Ca K solar lines.
Authors: Artzner, G.; Leibacher, J.; Vial, J. C.; Lemaire, P.;
Gouttebroze, P.
1978ApJ...224L..83A Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Calibrated full disk solar H I Lyman-alpha and Lyman-beta
profiles.
Authors: Lemaire, P.; Charra, J.; Jouchoux, A.; Vidal-Madjar, A.;
Artzner, G. E.; Vial, J. C.; Bonnet, R. M.; Skumanich, A.
1978ApJ...223L..55L Altcode:
Resolved solar H I Ly-alpha and -beta profiles have been recorded by the
French LPSP experiment on OSO 8. Intensity observations at the center
and the limb have been combined to obtain flux-equivalent profiles
(5.46 plus or minus 30 percent and 0.078 plus or minus 25 percent
erg/sq cm per sec for Ly-alpha and -beta, respectively). Comparison of
the flux profiles with unresolved calibration rocket profiles allows
one to obtain an absolute calibration.

---------------------------------------------------------
Title: Development of a High Resolution Ultraviolet Solar Spectrograph
to BE Launched on a Balloon Equatorial Platform
Authors: Lemaire, P.; Samain, D.
1978ESASP.135..283L Altcode: 1978esrb.rept..283L
A telescope-spectrometer instrumentation to study the sun in the
spectral ranges 1950-2200 A and 2650-2900 A is being developed to
obtain spatial, spectral, and time information on quiet and active
fine structures of the solar photosphere-chromosphere zone. To achieve
these objectives, an instrumentation able to give 0.5 arcsec angular
resolution on the solar surface and 0.01 A spectral resolution was
studied.

---------------------------------------------------------
Title: The LPSP instrument on OSO 8. II. In-flight performance and
preliminary results.
Authors: Bonnet, R. M.; Lemaire, P.; Vial, J. C.; Artzner, G.;
Gouttebroze, P.; Jouchoux, A.; Leibacher, J. W.; Skumanich, A.;
Vidal-Madjar, A.
1978ApJ...221.1032B Altcode:
The paper describes the in-flight performance for the first 18 months of
operation of the LPSP (Laboratoire de Physique Stellaire et Planetaire)
instrument incorporated in the OSO 8 launched June 1975. By means of
the instrument, an absolute pointing accuracy of nearly one second
was achieved in orbit during real-time operations. The instrument
uses a Cassegrain telescope and a spectrometer simultaneously
observing six wavelengths. In-flight performance is discussed with
attention to angular resolution, spectral resolution, dispersion
and grating mechanism (spectral scanner) stability, scattered light
background and dark current, photometric standardization, and absolute
calibration. Real-time operation and problems are considered with
reference to pointing system problems, target acquisition, and L-alpha
modulation. Preliminary results involving the observational program,
quiet sun and chromospheric studies, quiet chromospheric oscillation
and transients, sunspots and active regions, prominences, and aeronomy
investigations are reported.

---------------------------------------------------------
Title: Doppler Shifts measured in 0 VI line from OSO-B observations
above and in the vicinity of plage Mc Math 13738.
Authors: Lemaire, P.; Skumanich, A.; Artzner, G.; Gouttebroze, P.;
Vial, J. C.; Bonnet, R. M.; McWhirter, P.
1978BAAS...10Q.440L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: OSO-8 Radio and X-ray observations of the 19 April 1977 flare.
Authors: Skumanich, A.; Jouchoux, A.; Castelli, J.; Lemaire, P.;
Artzner, G.; Gouttebroze, P.; Vial, J. C.; Bonnet, R. M.
1978BAAS...10..441S Altcode:
No abstract at ADS

---------------------------------------------------------
Title: EUV observations of class-C X-ray flare by the LPSP
(Laboratoire de Physique Stellaire et Planétaire du Centre National
de la Recherche Scientifique) spectrometer on OSO-8.
Authors: Jouchoux, A.; Skumanich, A.; Bonnet, R. M.; Lemaire, P.;
Artzner, G.; Leibacher, J.; Vial, J. C.; Vidal-Madjar, A.
1977BAAS....9..432J Altcode:
No abstract at ADS

---------------------------------------------------------
Title: The LPSP experiment on OSO-8. I - Instrumentation, description
of operations, laboratory calibrations and pre-launch performances
Authors: Artzner, G.; Bonnet, R. M.; Vial, J. C.; Jouchoux, A.;
Leibacher, J.; Vidal-Madjar, A.; Lemaire, P.
1977SSI.....3..131A Altcode:
The characteristics of OSO-8, including its solar-pointed instrument
assembly and rasters, are discussed, as well as the accompanying
Laboratoire de Physique Stellaire et Planetaire (LPSP) instrumentation,
which is designed to study the solar atmosphere with high spatial,
spectral, and temporal resolution. The LPSP instrument, which consists
of two subassemblies, a Cassegrainian telescope and a spectrometer,
is described; main optical characteristics, including spectral lines
observed, and means of correcting aberrations and eliminating stray
light, are given for the spectrometer. Detectors and their capacities,
and various filter wheel configurations available for detection of
polarized light and discrimination of low orders of diffraction, are
also described. The observation program, which consists of a study of
solar prominences, flares, and dynamic and three-dimensional physical
structures of the chromosphere, as well as determination of seasonal
variations of some gases in earth's atmosphere, is reviewed. A detailed
account of pre-launch tests and calibration procedures is also given.

---------------------------------------------------------
Title: Extreme-Ultraviolet Observations of New Cycle Sunspots with
the LPSP Spectrometer from OSO-8
Authors: Skumanich, A.; Jouchoux, A.; Artzner, G.; Bonnet, R. M.;
Leibacher, J.; Lemaire, P.; Vial, J. C.; Vidal-Madjar, A.
1977BAAS....9..340S Altcode:
No abstract at ADS

---------------------------------------------------------
Title: On VI Profiles of Solar Quiet and Active Areas Recorded by
OSO-8 LPSP Experiment".
Authors: Lemaire, P.; Artzner, G.; Vial, J. C.; Bonnet, R. M.;
Gottebroze, P.; Jouchoux, A.; Vidal-Madjar, A.; McWhirter, P.;
Leibacher, J.; Skumainich, A.
1977uxsa.coll...46L Altcode: 1977IAUCo..43...46L
No abstract at ADS

---------------------------------------------------------
Title: OSO-8 Observations of the EUV Chromospheric Network
Authors: Artzner, G.; Bonnet, R. M.; Leibacher, J.; Lemaire, P.;
Skumanich, A.; Vial, J. C.; Vidal-Madjar, A.
1976BAAS....8..332A Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Solar OVI Profiles as Observed by the French Experiment
Aboard OSO-8
Authors: Lemaire, P.; Artzner, G.; Bonnet, R. M.; Vial, F. C.;
Skumanich, A.; Leibacher, J.; Vidal-Madjar, A.
1976BAAS....8R.331L Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Evolution of sunspot and active region morphology as observed
on the resonance lines of Ca+ (K, H), Mg+
(k, h), hydrogen (Lalpha , Lbeta ), and O VI from OSO-8 (LPSP).
Authors: Artzner, G.; Skumanich, A.; Bonnet, R. M.; Vidal-Madjar,
A.; Leibacher, J.; Lemaire, P.; Vial, J. C.
1976BAAS....8..397A Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Periodic temporal phenomena in the solar chromosphere as
observed from OSO-8 (LPSP).
Authors: Vial, J. C.; Leibacher, J.; Lemaire, P.; Artzner, G.; Bonnet,
R. M.; Skumanich, A.; Vidal-Madjar, A.
1976BAAS....8..397V Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Spatial variations of solar profiles of Ca+ H and
K, Mg+ h and k, and Lyman alpha and beta (H I) resonance
lines as observed from OSO-8 (LPSP).
Authors: Bonnet, R. M.; Artzner, G.; Leibacher, J.; Lemaire, P.;
Skumanich, A.; Vial, J. C.; Vidal-Madjar, A.
1976BAAS....8..397B Altcode:
No abstract at ADS

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Title: Prominence Observations with the OSO-8 French Experiment
Authors: Vial, J. C.; Artzner, G.; Bonnet, R. M.; Lemaire, P.;
Leibacher, J.; Skumanich, A.; Vidalmadjar, A.
1976BAAS....8..344V Altcode:
No abstract at ADS

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Title: High-Resolution Atmospheric Extinction Measurements from the
French Experiment on Board the NASA Spacecraft OSO-8
Authors: Vidal-Madjar, A.; Roble, R. G.; Mankin, W. G.; Artzner, G.;
Bonnet, R. M.; Lemaire, P.; Vial, J. C.
1976ASSL...61..117V Altcode: 1976aps..conf..117V
No abstract at ADS

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Title: High resolution atmospheric extinction measurements from the
French experiment on board the NASA spacecraft OSO-8
Authors: Vidal-Madjar, A.; Artzner, G.; Bonnet, R. M.; Lemaire, P.;
Vial, J. C.; Roble, R. G.; Mankin, W. G.
1976atps.proc..117V Altcode:
The French instrument aboard OSO-8 is a multichannel, high-resolution UV
spectrometer for observing very small areas of the sun simultaneously
in the Ca II, Mg II, Lyman alpha, and Lyman beta lines. By observing
extinction through the earth atmosphere, the spectrometer studies the
three-dimensional structure and the composition of the atmosphere. The
quality of data appears to give a 500 m vertical resolution both for
O3 and O2; O3 is observed primarily from 55 to 75 km, while O2 is
observed from 85 to 200 km. Data on the hydrogen absorption present a
new method for evaluating exospheric temperature and atomic hydrogen
density at each point of the exobase.

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Title: A center-to-limb analysis of solar Mg II lines.
Authors: Gouttebroze, P.; Lemaire, P.
1974A&A....34..375G Altcode:
Center-to-limb variations of Mg II resonance line profiles, deduced
from balloon spectra of the sun, are studied. Limb-darkening in the line
wings agrees satisfactorily with frequency-indpendent source functions
and Voigt profiles for line absorption coefficients. Estimates of
Doppler widths from a line core analysis show a rapid increase of
turbulence velocities with height. The source functions of the two
lines are found to be unequal at the same geometrical depth, which
suggests that collisional coupling between fine-structure levels (3p)
is weak. Apparent source function variations with frequency are found
in the spectral interval from 0.2 to 0.5 A from line center. Several
possible explanations of this fact (partially conherent scattering,
geometrical and dynamical effects) are discussed.

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Title: Magnesium II Doublet Profiles of Chromospheric Inhomogeneities
at the Center of The Solar Disk
Authors: Lemaire, P.; Skumanich, A.
1973BAAS....5R.275L Altcode:
No abstract at ADS

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Title: Magnesium II Doublet Profiles of Chromospheric Inhomogeneities
at the Center of the Solar Disk
Authors: Lemaire, P.; Skumanich, A.
1973A&A....22...61L Altcode:
Summary. An analysis of a balloon spectrum of the sun obtained on
June 24 1970, with 7" angnlar resolution and 25 mA spectral resolution
respectively is presented. Average cell, network and plages profiles
near the center of the solar disk are identified and compared with
profiles computed on the basis of recent chromospheric models. Key
words: sun - spectrum - ultraviolet chromosphere

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Title: High Resolution Balloon-Borne Spectrograph for the Near
Solar Ultraviolet
Authors: Lemaire, P.
1971IAUS...41..263L Altcode:
No abstract at ADS

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Title: Resonance Lines in the Solar Chromosphere
Authors: Lemaire, P.
1970IAUS...36..250L Altcode:
No abstract at ADS

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Title: High Resolution Balloon Spectra of the Sun in the Mg II
Doublet Lines II
Authors: Lemaire, P.
1969ApL.....3...43L Altcode:
No abstract at ADS

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Title: Stigmatic Balloon Spectra of the Solar MG II Doublet
Authors: Lemaire, P.; Blamont, J. E.
1967ApJ...150L.129L Altcode:
No abstract at ADS