L. Delchambre
A5004885355- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Scientific Research and Discoveries
- Distributed and Parallel Computing Systems
- Geomagnetism and Paleomagnetism Studies
- Geophysics and Gravity Measurements
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Cosmology and Gravitation Theories
- Remote Sensing in Agriculture
- CCD and CMOS Imaging Sensors
- Radio Astronomy Observations and Technology
- Astrophysical Phenomena and Observations
- Earth Systems and Cosmic Evolution
- Statistical and numerical algorithms
- Regional Economic and Spatial Analysis
- Relativity and Gravitational Theory
- Advanced Measurement and Metrology Techniques
- Complex Systems and Time Series Analysis
- Solar and Space Plasma Dynamics
- Advanced Statistical Methods and Models
University of Liège
2013-2024
Institut d'Astrophysique Spatiale
2017-2023
Max Planck Society
2018
Context. We present the second Gaia data release, DR2, consisting of astrometry, photometry, radial velocities, and information on astrophysical parameters variability, for sources brighter than magnitude 21. In addition epoch astrometry photometry are provided a modest sample minor planets in solar system. Aims. A summary contents DR2 is presented, accompanied by discussion differences with respect to DR1 an overview main limitations which still survey. Recommendations made responsible use...
Gaia is a cornerstone mission in the science programme of EuropeanSpace Agency (ESA). The spacecraft construction was approved 2006, following study which original interferometric concept changed to direct-imaging approach. Both and payload were built by European industry. involvement scientific community focusses on data processing for international Data Processing Analysis Consortium (DPAC) selected 2007. launched 19 December 2013 arrived at its operating point, second Lagrange point...
We present the early installment of third Gaia data release, EDR3, consisting astrometry and photometry for 1.8 billion sources brighter than magnitude 21, complemented with list radial velocities from DR2. EDR3 contains celestial positions apparent brightness in G approximately sources. For 1.5 those sources, parallaxes, proper motions, (G_BP-G_RP) colour are also available. The passbands G, G_BP, G_RP provided as part release. ease use, 7 million DR2 included this after removal a small...
We present the third data release of European Space Agency's Gaia mission, GDR3. The GDR3 catalogue is outcome processing raw collected with instruments during first 34 months mission by Data Processing and Analysis Consortium. contains same source list, celestial positions, proper motions, parallaxes, broad band photometry in G, G$_{BP}$, G$_{RP}$ pass-bands already Early Third Release. introduces an impressive wealth new products. More than 33 million objects ranges $G_{rvs} < 14$ $3100...
At about 1000 days after the launch of Gaia we present first data release, DR1, consisting astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. We summarize DR1 provide illustrations scientific quality data, followed by a discussion limitations due to preliminary nature this release. consists of: primary astrometric set which contains positions, parallaxes, mean proper motions 2 million brightest stars in common with Hipparcos Tycho-2 catalogues secondary...
Context. Gaia Data Release 2 provides high-precision astrometry and three-band photometry for about 1.3 billion sources over the full sky. The precision, accuracy, homogeneity of both are unprecedented. Aims. We highlight power DR2 in studying many fine structures Hertzsprung-Russell diagram (HRD). allows us to present different HRDs, depending particular on stellar population selections. do not aim here completeness terms types stars or evolutionary aspects. Instead, we have chosen several...
The goal of this paper is to demonstrate the outstanding quality second data release Gaia mission and its power for constraining many different aspects dynamics satellites Milky Way. We focus here on determining proper motions 75 Galactic globular clusters, nine dwarf spheroidal galaxies, one ultra-faint system, Large Small Magellanic Clouds. Using extracted from archive, we derived parallaxes these systems, as well their uncertainties. that errors, statistical systematic, are relatively...
We produce a clean and well-characterised catalogue of objects within 100\,pc the Sun from \G\ Early Data Release 3. characterise through comparisons to full data release, external catalogues, simulations. carry out first analysis science that is possible with this sample demonstrate its potential best practices for use. The selection used selected training sets, machine-learning procedures, astrometric quantities, solution quality indicators determine probability reliable. set construction...
To illustrate the potential of GDR2, we provide a first look at kinematics Milky Way disc, within radius several kiloparsecs around Sun. We benefit for time from sample 6.4 million F-G-K stars with full 6D phase-space coordinates, precise parallaxes, and Galactic cylindrical velocities . From this sample, extracted sub-sample 3.2 giant to map velocity field disc $\sim$5~kpc $\sim$13~kpc centre up 2~kpc above below plane. also study distribution 0.3 solar neighbourhood ($r < 200$~pc), median...
We present the early installment of third Gaia data release, EDR3, consisting astrometry and photometry for 1.8 billion sources brighter than magnitude 21, complemented with list radial velocities from DR2. EDR3 contains celestial positions apparent brightness in G approximately sources. For 1.5 those sources, parallaxes, proper motions, (G_BP-G_RP) colour are also available. The passbands G, G_BP, G_RP provided as part release. ease use, 7 million DR2 included this after removal a small...
The Gaia DR3 Catalogue contains for the first time about eight hundred thousand solutions with either orbital elements or trend parameters astrometric, spectroscopic and eclipsing binaries, combinations of them. This paper aims to illustrate huge potential this large non-single star catalogue. Using together models a catalogue tens thousands stellar masses, lower limits, partly consistent flux ratios, has been built. Properties concerning completeness binary catalogues are discussed,...
The chemo-physical parametrisation of stellar spectra is essential for understanding the nature and evolution stars Galactic populations. Gaia DR3 contains RVS data performed by General Stellar Parametriser-spectroscopy, module. Here we describe first 34 months observations. GSP-spec estimates parameters from combined single stars. main analysis workflow described here, MatisseGauguin, based on projection optimisation methods provides atmospheric parameters; individual chemical abundances N,...
(Abridged) Blue (BP) and Red (RP) Photometer low-resolution spectral data is one of the exciting new products in Gaia Data Release 3 (Gaia DR3). We calibrate about 65 billion individual transit spectra onto same mean BP/RP instrument through a series calibration steps, including background subtraction, CCD geometry an iterative procedure for efficiency as well variations line-spread function dispersion across focal plane time. The calibrated are then combined each source terms expansion into...
Gaia Data Release 3 contains a wealth of new data products for the community. Astrophysical parameters are major component this release. They were produced by inference system (Apsis) within Processing and Analysis Consortium. The aim paper is to describe overall content astrophysical in how they produced. In Apsis we use mean BP/RP RVS spectra along with astrometry photometry, derive following parameters: source classification probabilities 1.6 billion objects, interstellar medium...
We present the General Stellar Parameterizer from Photometry (GSP-Phot), which is part of astrophysical parameters inference system (Apsis). GSP-Phot designed to produce a homogeneous catalogue for hundreds millions single non-variable stars based on their astrometry, photometry, and low-resolution BP/RP spectra. These are effective temperature, surface gravity, metallicity, absolute $M_G$ magnitude, radius, distance, extinction each star. uses Bayesian forward-modelling approach...
Context. Gaia Data Release 3 contains astrometry and photometry results for about 1.8 billion sources based on observations collected by the European Space Agency (ESA) satellite during first 34 months of its operational phase (the same period covered early 3; EDR3). Low-resolution spectra 220 million are one important new data products included in this release. Aims. In paper, we focus external calibration low-resolution spectroscopic content, describing input data, algorithms, processing,...
Gaia Data Release 3 contains a wealth of new data products for the community. Astrophysical parameters are major component this release. They were produced by inference system (Apsis) within Processing and Analysis Consortium. The aim paper is to describe overall content astrophysical in how they produced. In Apsis we use mean BP/RP RVS spectra along with astrometry photometry, derive following parameters: source classification probabilities 1.6 billion objects, interstellar medium...
With the most recent Gaia data release number of sources with complete 6D phase space information (position and velocity) has increased to well over 33 million stars, while stellar astrophysical parameters are provided for more than 470 sources, in addition identification 11 variable stars. Using variability classifications DR3, we select various populations explore identify non-axisymmetric features disc Milky Way both configuration velocity space. about 580 thousand identified as hot OB...
Gravitational waves from black-hole merging events have revealed a population of extra-galactic BHs residing in short-period binaries with masses that are higher than expected based on most stellar evolution models - and also known stellar-origin black holes our Galaxy. It has been proposed those high-mass the remnants massive metal-poor stars. Gaia astrometry is to uncover many Galactic wide-binary systems containing dormant BHs, which may not detected before. The study this will provide...
The Gaia Data Release 2 contains the 1st release of radial velocities complementing kinematic data a sample about 7 million relatively bright, late-type stars. Aims: This paper provides detailed description spectroscopic processing pipeline, and approach adopted to derive presented in DR2. Methods: pipeline must perform four main tasks: (i) clean reduce spectra observed with Radial Velocity Spectrometer (RVS); (ii) calibrate RVS instrument, including wavelength, straylight, line-spread...
We compare the Gaia DR2 and EDR3 performances in study of Magellanic Clouds show clear improvements precision accuracy new release. also that systematics still present data make determination 3D geometry LMC a difficult endeavour; this is at very limit usefulness astrometry, but it may become feasible with use additional external data. derive radial tangential velocity maps global profiles for several subsamples we defined. To our knowledge, first time two planar components ordered random...
The Gaia satellite will survey the entire celestial sphere down to 20th magnitude, obtaining astrometry, photometry, and low resolution spectrophotometry on one billion astronomical sources, plus radial velocities for over hundred million stars. Its main objective is take a census of stellar content our Galaxy, with goal revealing its formation evolution. Gaia's unique feature measurement parallaxes proper motions hitherto unparalleled accuracy many objects. As survey, physical properties...