T. Paumard
A5040601859- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Adaptive optics and wavefront sensing
- Pulsars and Gravitational Waves Research
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- History and Developments in Astronomy
- Optical Systems and Laser Technology
- Geophysics and Gravity Measurements
- Calibration and Measurement Techniques
- High-pressure geophysics and materials
- Advanced optical system design
- Molecular Spectroscopy and Structure
- Spectroscopy and Laser Applications
- Advanced Measurement and Metrology Techniques
- Optical Coherence Tomography Applications
- Optical measurement and interference techniques
- Atmospheric Ozone and Climate
- Mechanics and Biomechanics Studies
- Advanced Optical Sensing Technologies
Max Planck Institute for Extraterrestrial Physics
2005-2024
Université de Versailles Saint-Quentin-en-Yvelines
2014-2024
Sorbonne Université
2014-2024
Université Paris Cité
2014-2024
Laboratoire d’études spatiales et d’instrumentation en astrophysique
2014-2024
Observatoire de Paris
2014-2024
Centre National de la Recherche Scientifique
2014-2024
Université Paris Sciences et Lettres
2016-2024
Sorbonne Paris Cité
2016-2024
Délégation Paris 7
2010-2024
The highly elliptical, 16-year-period orbit of the star S2 around massive black hole candidate Sgr A ✻ is a sensitive probe gravitational field in Galactic centre. Near pericentre at 120 AU ≈ 1400 Schwarzschild radii, has an orbital speed ≈7650 km s −1 , such that first-order effects Special and General Relativity have now become detectable with current capabilities. Over past 26 years, we monitored radial velocity motion on sky S2, mainly SINFONI NACO adaptive optics instruments ESO Very...
We report on 75 mas resolution, near-IR imaging spectroscopy within the central 30 lt-days of Galactic center, taken with new adaptive optics-assisted integral-field spectrometer SINFONI ESO VLT. To a limiting magnitude K ~ 16, 9 10 stars in 04, and 13 17 out to 07 from black hole have spectral properties B0-B9 main-sequence stars. Based 2.1127 μm He I line width, all brighter early-type normal rotation velocities, similar solar neighborhood combine radial velocities SHARP/NACO astrometry...
GRAVITY is a new instrument to coherently combine the light of European Southern Observatory Very Large Telescope Interferometer form telescope with an equivalent 130 m diameter angular resolution and collecting area 200 m$^2$. The comprises fiber fed integrated optics beam combination, high spectroscopy, built-in analysis control, near-infrared wavefront sensing, phase-tracking, dual operation laser metrology [...]. This article gives overview reports on performance first astronomical...
We report the definite spectroscopic identification of ≃40 OB supergiants, giants, and main-sequence stars in central parsec Galaxy. Detection their absorption lines has become possible with high spatial spectral resolution sensitivity adaptive optics integral field spectrometer SPIFFI/SINFONI on ESO VLT. Several these appear to be helium- nitrogen-rich. Almost all ≃80 massive now known (central arcsecond excluded) reside one two somewhat thick (⟨ /R⟩ ≃ 0.14) rotating disks. These stellar...
The star S2 orbiting the compact radio source Sgr A* is a precision probe of gravitational field around closest massive black hole (candidate). Over last 2.7 decades we have monitored star’s radial velocity and motion on sky, mainly with SINFONI NACO adaptive optics (AO) instruments ESO VLT, since 2017, four-telescope interferometric beam combiner instrument GRAVITY. In this Letter report first detection General Relativity (GR) Schwarzschild Precession (SP) in S2’s orbit. Owing to its highly...
We report the detection of continuous positional and polarization changes compact source SgrA* in high states ('flares') its variable near- infrared emission with near-infrared GRAVITY-Very Large Telescope Interferometer (VLTI) beam-combining instrument. In three prominent bright flares, position centroids exhibit clockwise looped motion on sky, scales typically 150 micro-arcseconds over a few tens minutes, corresponding to about 30% speed light. At same time, flares rotation angle,...
We present new observations of the nuclear star cluster in central parsec Galaxy with adaptive optics assisted, integral field spectrograph SINFONI on ESO/VLT. Our work allows spectroscopic detection early- and late-type stars to mK ⩾ 16, more than 2 mag deeper our previous data sets. result a total sample 177 bona fide early-type stars. find that most these Wolf Rayet (WR), O-, B-stars reside two strongly warped disks between 08 12'' from Sgr A*, as well compact concentration (the S-star...
We present a 0.16% precise and 0.27% accurate determination of R0, the distance to Galactic Center. Our measurement uses star S2 on its 16-year orbit around massive black hole Sgr A* that we followed astrometrically spectroscopically for 27 years. Since 2017, added near-infrared interferometry with VLTI beam combiner GRAVITY, yielding direct separation vector between an accuracy as good 20 micro-arcsec in best cases. passed pericenter highly eccentric May 2018, passage dense sampling...
The stars orbiting the compact radio source Sgr A* in Galactic Centre are precision probes of gravitational field around closest massive black hole. In addition to adaptive optics assisted astrometry (with NACO / VLT) and spectroscopy SINFONI VLT, NIRC2 Keck GNIRS Gemini) over three decades, since 2016/2017 we have obtained 30-100 mu-as with four-telescope interferometric beam combiner GRAVITY VLTI reaching a sensitivity mK = 20 when combining data from one night. We present simultaneous...
The GRAVITY instrument on the ESO VLTI pioneers field of high-precision near-infrared interferometry by providing astrometry at $10 - 100\,\mu$as level. Measurements such high precision crucially depend control systematic effects. Here, we investigate how aberrations introduced small optical imperfections along path from telescope to detector affect astrometry. We develop an analytical model that describes impact measurement complex visibilities. Our formalism accounts for pupil-plane and...
Tight relationships exist in the local universe between central stellar properties of galaxies and mass their supermassive black hole. These suggest holes co-evolve, with main regulation mechanism being energetic feedback from accretion onto hole during its quasar phase. A crucial question is how relationship evolves time; a key epoch to probe this at peaks star formation growth 8-12 billion years ago (redshifts 1-3). Here we report dynamical measurement luminous redshift 2, look back time...
By using the GRAVITY instrument with near-infrared (NIR) Very Large Telescope Interferometer (VLTI), structure of broad (emission-)line region (BLR) in active galactic nuclei (AGNs) can be spatially resolved, allowing central black hole (BH) mass to determined. This work reports new NIR VLTI/GRAVITY interferometric spectra for four type 1 AGNs (Mrk 509, PDS 456, Mrk 1239, and IC 4329A) resolved broad-line emission. Dynamical modelling data constrains BLR radius BH measurements our targets...
Aims.We study a sample composed of 28 the brightest stars in Arches cluster. Our aim is to constrain their stellar and wind properties establish nature evolutionary status.
The central parsec around the supermassive black hole in Galactic center (GC) hosts more than 100 young and massive stars. Outside cusp (R ∼ 1'') majority of these O Wolf–Rayet (W–R) stars reside a main clockwise system, plus second, less prominent disk or streamer system at large angles with respect to system. Here we present results from new observations GC AO-assisted near-infrared imager NACO integral field spectrograph SINFONI on ESO/VLT. These include detection 27 reliably measured...
Context.How star formation proceeds in the Galactic Center is a debated question. Addressing this question will help us understand origin of cluster massive stars near supermassive black hole, and more generally, starburst phenomena galactic nuclei. In that context, it crucial to know properties young central parsec Galaxy.
This paper reports measurements of Sgr A* made with NACO in L' -band (3.80 um), Ks-band (2.12 um) and H-band (1.66 VISIR N-band (11.88 at the ESO VLT, as well XMM-Newton X-ray (2-10 keV) wavelengths. On 4 April, 2007, a very bright flare was observed from simultaneously L'-band No emission detected using VISIR. The resulting SED has blue slope (beta > 0 for nuL_nu ~ nu^beta, consistent nu^0.4) between 12 micron 3.8 micron. For first time our high quality data allow detailed comparison...
To date, infrared interferometry at best achieved contrast ratios of a few times $10^{-4}$ on bright targets. GRAVITY, with its dual-field mode, is now capable high observations, enabling the direct observation exoplanets. We demonstrate technique HR8799, young planetary system composed four known giant used GRAVITY fringe tracker to lock fringes central star, and integrated off-axis HR8799e planet situated 390 mas from star. Data reduction included post-processing remove flux leaking star...
Context. β Pictoris is arguably one of the most studied stellar systems outside our own. Some 30 yr observations have revealed a highly-structured circumstellar disk, with rings, belts, and giant planet: b. However very little known about how this system came into being. Aims. Our objective to estimate C/O ratio in atmosphere b obtain an dynamical mass planet, as well refine its orbital parameters using high-precision astrometry. Methods. We used GRAVITY instrument four 8.2 m telescopes Very...
We present near-infrared interferometric data on the Seyfert 2 galaxy NGC 1068, obtained with GRAVITY instrument European Southern Observatory Very Large Telescope Interferometer. The extensive baseline coverage from 5 to 60 M\lambda allowed us reconstruct a continuum image of nucleus an unrivaled 0.2 pc resolution in K-band. find thin ring-like structure emission radius r = 0.24+/-0.03 pc, inclination i 70+/-5 deg, position angle PA -50+/-4 and h/r < 0.14, which we associate dust...
Methods used to detect giant exoplanets can be broadly divided into two categories: indirect and direct. Indirect methods are more sensitive planets with a small orbital period, whereas direct detection is orbiting at large distance from their host star. %, thus on long period. This dichotomy makes it difficult combine the techniques single target once. Simultaneous measurements made by offer possibility of determining mass luminosity method testing formation models. Here, we aim show how...
We present K-band interferometric observations of the PDS 70 protoplanets along with their host star using VLTI/GRAVITY. obtained spectra and 100 $\mu$as precision astrometry both b c in two epochs, as well spatially resolving hot inner disk around star. Rejecting unstable orbits, we found a nonzero eccentricity for $0.17 \pm 0.06$, near-circular orbit c, an orbital configuration that is consistent planets migrating into 2:1 mean motion resonance. Enforcing dynamical stability, 95% upper...
Context. The Event Horizon Telescope (EHT) collaboration recently obtained first images of the surroundings supermassive compact object M87* at center galaxy M87. Aims. We want to develop a simple analytic disk model for accretion flow M87*. Compared general-relativistic magnetohydrodynamic (GRMHD) models, it has advantage being independent turbulent character flow, and controlled by only few easy-to-interpret, physically meaningful parameters. use this predict image assuming that is either...