A5066395722- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Molecular Spectroscopy and Structure
- Astronomical Observations and Instrumentation
- History and Developments in Astronomy
- Historical and Architectural Studies
- Gamma-ray bursts and supernovae
- Atmospheric Ozone and Climate
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- Photonic and Optical Devices
- Advanced Combustion Engine Technologies
- Pulsars and Gravitational Waves Research
- High-pressure geophysics and materials
- Advanced optical system design
- Spectroscopy and Laser Applications
- Electromagnetic Scattering and Analysis
- Radiation Therapy and Dosimetry
- Historical Geography and Cartography
- Calibration and Measurement Techniques
- GNSS positioning and interference
- Space Science and Extraterrestrial Life
Centre National de la Recherche Scientifique
2012-2024
Université de Bordeaux
2013-2024
Laboratoire d'Astrophysique de Bordeaux
2014-2024
Observatoire Aquitain des Sciences de l'Univers
2013-2015
Massachusetts Institute of Technology
2012
European Southern Observatory
2000-2011
Astrophysique, Instrumentation et Modélisation
2010-2011
Université Paris Cité
2006-2011
Délégation Paris 7
2009-2011
Observatoire de Paris
2006-2011
The availability of a number new interferometric measurements Main Sequence and subgiant stars makes it possible to calibrate the surface brightness relations these using exclusively direct angular diameter measurements. These empirical laws make predict limb darkened diameters dwarfs subgiants their dereddened Johnson magnitudes, or effective temperature. smallest intrinsic dispersions in are obtained for based on K L instance . Our calibrations valid between spectral types A0 M2 dwarf...
Context. TW Hya is a classical T Tauri star that shows significant radial-velocity variations in the optical regime. These have been attributed to 10 planet orbiting at 0.04 AU.
We measured the radii of 7 low and very low-mass stars using long baseline interferometry with VLTI interferometer its VINCI AMBER near-infrared recombiners. use these new data, together literature measurements, to examine luminosity- radius mass-radius relations for K M dwarfs. The precision interferometric now competes what can be obtained double-lined eclipsing binaries. Interferometry provides access much less active stars, as well better distances luminosities, therefore complements...
Context. Dust is expected to be ubiquitous in extrasolar planetary systems owing the dynamical activity of minor bodies. Inner dust populations are, however, still poorly known because high contrast and small angular separation with respect their host star, yet, a proper characterisation exozodiacal mandatory for design future Earth-like planet imaging missions.
ou non, émanant des établissements d'enseignement et de recherche français étrangers, laboratoires publics privés.
We have obtained high-precision interferometric measurements of Vega with the CHARA Array and FLUOR beam combiner in K' band at projected baselines between 103 273 m. The measured visibility amplitudes beyond first lobe are significantly weaker than expected for a slowly rotating star characterized by single effective temperature surface gravity. Our measurements, when compared to synthetic visibilities spectrophotometry from Roche-von Zeipel gravity-darkened model atmosphere, provide strong...
Context.Only a handful of debris disks have been imaged up to now. Due the need for high dynamic range and angular resolution, very little is known about inner planetary region, where small amounts warm dust are expected be found.
Although debris discs have been detected around a significant number of main-sequence stars, only few them are known to harbour hot dust in their inner part where terrestrial planets may formed. Thanks infrared interferometric observations, it is possible obtain direct measurement these regions, which prime importance for preparing future exo-Earth characterisation missions. In this context, we resolved the exozodiacal disc Vega with help stellar interferometry and estimated integrated...
The accuracy of masses pre-main sequence (PMS) stars derived from their locations on the Hertzsprung-Russell Diagram (HRD) can be tested by comparison with accurate and precise determined independently. We present 29 single in Taurus star-forming region (SFR) 3 Ophiuchus SFR measured dynamically to a precision at least $10 \%$. Our results include 9 updated mass determinations that have not had dynamical published before. This list fundamental, masses, M$_{dyn}$, is drawn larger 39 targets 6...
Aims: We attempt to determine the masses of single or multiple young T Tauri and HAeBe stars from rotation their Keplerian disks. Methods:We used IRAM PdBI interferometer perform arcsecond resolution images CN N=2-1 transition with good spectral resolution. Integrated spectra 30-m radiotelescope show that is relatively unaffected by contamination molecular clouds. Our sample includes 12 sources, among which isolated like DM Tau MWC 480 are demonstrate method its accuracy. derive dynamical...
(abridged) We used the IRAM 30-m to perform a sensitive wideband survey of 30 protoplanetary disks in Taurus Auriga region. simultaneously observed HCO$^+$(3-2), HCN(3-2), C$_2$H(3-2), CS(5-4), and two transitions SO. combine results with previous which $^{13}$CO (2-1), CN(2-1), o-H$_2$CO lines one use available interferometric data derive excitation temperatures CN C$_2$H several sources. determine characteristic sizes gas column densities all molecules using parametric power-law disk...
Context. Determining the gas density and temperature structures of protoplanetary disks is a fundamental task in order to constrain planet formation theories. This challenging procedure most determinations are based on model-dependent assumptions. Aims. We attempt direct determination radial vertical structure Flying Saucer disk, thanks its favorable inclination 90 degrees. Methods. present method tomographic study an edge-on disk. Using ALMA, we observe at 0.5″ resolution CO J = 2–1 CS 5–4....
Context. Planet formation is expected to take place in the first million years of a planetary system through various processes, which remain be tested observations. Aims. With recent discovery, using ALMA, two gaseous spiral arms inside 120 au cavity and connected dusty spirals, famous protoplanetary disk around AB Aurigae presents strong incentive for investigating mechanisms that lead giant planet formation. A candidate protoplanet located arm has already been claimed an earlier study...
Context.The quest for hot dust in the central region of debris disks requires high resolution and dynamic range imaging. Near-infrared interferometry is a powerful means to directly detect faint emission from grains.
Context. The young active star BD +20 1790 is believed to host a substellar companion, revealed by radial-velocity measurements that detected the reflex motion induced on parent star. Aims. A complete characterisation of signal necessary in order assess its nature. Methods. We used CORALIE spectrograph obtain precise (~10 m/s) velocity this star, while characterizing bisector span variations. Particular attention was given correctly sample both proposed planetary orbital period, 7.8 days,...
We use the IRAM 30-m telescope to perform a sensitive search for CN N=2-1 in 42 T Tauri or Herbig Ae systems located mostly Taurus-Auriga region. $^{13}$CO J=2-1 is observed simultaneously indicate level of confusion with surrounding molecular cloud. The bandpass also contains two transitions ortho-H$_2$CO, one SO and C$^{17}$O line which provide complementary information on nature emission. While general dominated by residual emission from cloud, exhibits high disk detection rate $> 50$%...
The increased sensitivity of millimeter-wave facilities now makes possible the detection low amounts gas in debris disks. Some gas-rich disks harbor peculiar properties, with pristine and secondary generated dust. origin these hybrid is strongly debated current sample too sparse to understand this phenomenon. More detections are necessary increase statistics on population. Lying at final stages evolution proto-planetary beginning disk phase, objects could provide new insight into processes...
We report the results of ALMA observations a protoplanetary disk surrounding Herbig Ae star AB Aurigae. obtained high-resolution (0.1"; 14 au) images in $^{12}$CO (J=2-1) emission and dust continuum at wavelength 1.3 mm. The is detected center ring with radius $\sim$ 120 au. CO dominated by two prominent spirals within ring. These are trailing appear to be about 4 times brighter than their medium. Their kinematics consistent Keplerian rotation an inclination 23 degree. apparent...
(abridged) Most Class II sources (of nearby star forming regions) are surrounded by disks with weak millimeter continuum emission. These "faint" may hold clues to the disk dissipation mechanism. We attempt determine characteristics of such faint around classical T Tauri stars, and explore link between faintness proposed dispersal mechanisms (accretion, viscous spreading, photo-evaporation, planetary system formation). performed high-angular resolution (0.3") imaging a small sample (9...