A5017539702- Adaptive optics and wavefront sensing
- Optical Systems and Laser Technology
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Advanced optical system design
- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- Optical Wireless Communication Technologies
- Astronomical Observations and Instrumentation
- Calibration and Measurement Techniques
- Astro and Planetary Science
- Optical Coherence Tomography Applications
- Advanced Measurement and Metrology Techniques
- History and Developments in Astronomy
- Optical measurement and interference techniques
- Advanced Optical Sensing Technologies
- Optical Network Technologies
- High-pressure geophysics and materials
- Advanced Image Processing Techniques
- Meteorological Phenomena and Simulations
- Mechanics and Biomechanics Studies
- Photonic and Optical Devices
- Infrared Target Detection Methodologies
- solar cell performance optimization
Sorbonne Université
2014-2024
Laboratoire d’études spatiales et d’instrumentation en astrophysique
2015-2024
Centre National de la Recherche Scientifique
2014-2024
Délégation Paris 7
2010-2024
Observatoire de Paris
2014-2024
Université Paris Sciences et Lettres
2016-2024
Université Paris Cité
2014-2024
Australian National University
2019-2024
Sorbonne Paris Cité
2016-2024
Université de Versailles Saint-Quentin-en-Yvelines
2011-2024
Here we show that the ~10 Myr Beta Pictoris system hosts a massive giant planet, b, located 8 to 15 AU from star. This result confirms gas planets form rapidly within disks and validates use of disk structures as fingerprints embedded planets. Among few already imaged, b is closest its parent Its short period could allow recording full orbit 17 years.
Since the discovery of its dusty disk in 1984, Beta Pictoris has become prototype young early-type planetary systems, and there are now various indications that a massive Jovian planet is orbiting star at ~ 10 AU. However, no planets have been detected around this so far. Our goal was to investigate close environment Pic, searching for companion(s). Deep adaptive-optics L'-band images Pic were recorded using NaCo instrument Very Large Telescope. A faint point-like signal projected distance 8...
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...
The Gemini Multi-conjugate adaptive optics System (GeMS) at the South telescope in Cerro Pach{\'o}n is first sodium-based multi-Laser Guide Star (LGS) system. It uses five LGSs and two deformable mirrors to measure compensate for atmospheric distortions. GeMS project started 1999, saw light 2011. now regular operation, producing images close diffraction limit near infrared, with uniform quality over a field of view square arcminutes. present paper (I) one two-paper review GeMS. describes...
We investigate the fueling and feedback of nuclear activity in Seyfert 2 galaxy NGC1068, by studying distribution kinematics molecular gas torus its connections. use ALMA to image emission a set tracers circumnuclear disk (CND) using CO(2-1), CO(3-2) HCO+(4-3) lines with spatial resolutions ~0.03"-0.09"(2-6pc). resolves CND as an asymmetric ringed D~400pc-size mass ~1.4x10^8 Msun. The inner edge ring is associated edge-brightened arcs NIR polarized identified working surface AGN ionized...
Adaptive optics provides real time correction of wavefront disturbances on ground based telescopes.Optimizing control and performance is a key issue for ever more demanding instruments larger telescopes affected not only by atmospheric turbulence, but also vibrations, windshake tracking errors.Linear Quadratic Gaussian achieves optimal when provided with temporal model the disturbance.We present in this paper first on-sky results Kalman filter LQG vibration mitigation CANARY instrument at...
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...
Using VLTI/GRAVITY and SINFONI data, we investigate the subparsec gas dust structure around nearby type 1 active galactic nucleus (AGN) hosted by NGC 3783. The K -band coverage of GRAVITY uniquely allows simultaneous analysis size kinematics broad line region (BLR), near-infrared(near-IR)-continuum-emitting hot dust, coronal (CLR). We find BLR, probed through Br γ emission, to be well described a rotating, thick disc with radial distribution clouds peaking in inner region. In our BLR model,...
Context. A giant planet was recently discovered around the young star β Pictoris. This is closest to its parent ever imaged. With an estimated mass of about 9 MJup and separation 8–15 AU, it explains most peculiarities Pictoris disk.
Context. A new challenging adaptive optics (AO) system, called multi-object (MOAO), has been successfully demonstrated on-sky for the first time at 4.2 m William Herschel Telescope, Canary Islands, Spain, end of September 2010.
We present new near-infrared VLTI/GRAVITY interferometric spectra that spatially resolve the broad Br$\gamma$ emission line in nucleus of active galaxy IRAS 09149-6206. use these data to measure size region (BLR) and estimate mass central black hole. Using an improved phase calibration method reduces differential uncertainty 0.05 degree per baseline across spectrum, we detect a signal reaches maximum ~0.5 between continuum. This represents offset ~120 $\mu$as (0.14 pc) BLR centroid hot dust...
We present a novel formulation of closed-loop adaptive optics (AO) control as multi-agent reinforcement learning (MARL) problem in which the controller is able to learn non-linear policy and does not need priori information on dynamics atmosphere. identify different challenges applying (RL) method AO and, solve them, propose combination model-free MARL for with an autoencoder neural network mitigate effect noise. Moreover, we extend current existing methods error budget analysis include RL...
We present the first high‐contrast images obtained at ESO Very Large Telescope using a four‐quadrant phase mask coronagraph. The two‐night commissioning was carried out in 2004 January on NACO, near‐IR camera with adaptive optics UT4. evaluated behavior of coronagraph variety astrophysical targets: binary stars, circumstellar disks, and active galactic nuclei. performance is agreement our expectations based numerical simulations. provides stellar peak attenuation factor about 10 average (for...
We present recent results from the initial testing of an artificial neural network (ANN)-based tomographic reconstructor Complex Atmospheric Reconstructor based on Machine lEarNing (CARMEN) CANARY, adaptive optics demonstrator operated 4.2 m William Herschel Telescope, La Palma. The was compared with contemporaneous data using Learn and Apply (L&A) reconstructor. find that fully optimized L&A outperforms CARMEN by approximately 5 per cent in Strehl ratio or 15 nm rms wavefront error. also...
MICADO will equip the E-ELT with a first light capability for diffraction limited imaging at near-infrared wavelengths. The instrument's observing modes focus on various flavours of imaging, including astrometric, high contrast, and time resolved. There is also single object spectroscopic mode optimised wavelength coverage moderately resolution. This contribution provides an overview key functionality instrument, outlining scientific rationale its modes. interface between adaptive optics...
MICADO is the adaptive optics imaging camera for E-ELT. It has been designed and optimised to be mounted LGS-MCAO system MAORY, will provide diffraction limited over a wide (~1 arcmin) field of view. For initial operations, it can also used with its own simpler AO module that provides on-axis performance using natural guide stars. We discuss instrument's key capabilities expected performance, show how science drivers have shaped design. outline technical concept, from opto-mechanical design...
Aims. One of the main observational challenges for investigating central regions active galactic nuclei (AGN) at short wavelengths, using high angular resolution, and contrast observations, is to directly detect circumnuclear optically thick material hiding core emission when viewed edge-on. The lack direct evidence limiting our understanding AGN, several scenarios have been proposed cope diverse observed aspects activity in a unified approach.
The compute and control for adaptive optics (cacao) package is an open-source modular software environment real-time of modern system. By leveraging many-core CPU GPU hardware, it can scale up to meet the demanding computing requirements current future high frame rate, actuator count (AO) systems. cacao's design enables both simple/barebone operation, complex full-featured AO centered on data streams that hold in shared memory along with a synchronization mechanism processes. Users...
We propose a novel control approach that combines offline supervised learning to address the challenges posed by non-linear phase reconstruction using unmodulated pyramid wavefront sensors (P-WFS) and online reinforcement for predictive control. The uses high-order P-WFS drive tip-tilt stage high-dimensional mirror concurrently. Simulation results demonstrate our method outperforms traditional techniques, showing significant improvements in performance under challenging conditions such as...
We recently reported on the detection of a possible planetary-mass companion to Beta Pictoris at projected separation 8 AU from star, using data taken in November 2003 with NaCo, adaptive-optics system installed Very Large Telescope UT4. Eventhough no second epoch was available, there are strong arguments favor gravitationally bound rather than background object. If confirmed and located physical AU, this young, hot (~1500 K), massive Jovian (~8 Mjup) would be closest planet its star ever...
We present a detailed analysis of high-resolution near-infrared imaging and spectroscopy the potential star cluster IRS13E very close to massive black hole in Galactic center. detect 19 objects from Ks-band images, 15 which are also detected reliably H band. derive consistent proper motions for these two bands. Most share similar westward motion. characterize using (1.45–2.45 μm) (narrowband) (1.66 L' band (3.80 μm). Nine both Ks bands red, we find that they all with being warm dust clumps....
This White Paper presents the scientific motivations for a multi-object spectrograph (MOS) on European Extremely Large Telescope (E-ELT). The MOS case draws all fields of contemporary astronomy, from extra-solar planets, to study halo Milky Way and its satellites, resolved stellar populations in nearby galaxies out observations earliest 'first-light' structures partially-reionised Universe. material presented here results thorough discussions within community over past four years, building...