A5028898239- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Radio Astronomy Observations and Technology
- Spectroscopy and Laser Applications
- CCD and CMOS Imaging Sensors
- Cosmology and Gravitation Theories
- Pulsars and Gravitational Waves Research
- Calibration and Measurement Techniques
- History and Developments in Astronomy
- Photocathodes and Microchannel Plates
- Scientific Research and Discoveries
- Geophysics and Gravity Measurements
- Plant Water Relations and Carbon Dynamics
- Semiconductor Lasers and Optical Devices
- Remote Sensing in Agriculture
- Dark Matter and Cosmic Phenomena
- Superconducting and THz Device Technology
- Advanced optical system design
Université Claude Bernard Lyon 1
2016-2025
École Normale Supérieure de Lyon
2016-2025
Centre National de la Recherche Scientifique
2016-2025
Centre de Recherche Astrophysique de Lyon
2016-2025
Observatoire de Lyon
2012-2024
University of Geneva
2011-2024
PSG INSTITUTE OF TECHNOLOGY AND APPLIED RESEARCH
2024
California Institute of Technology
2004-2023
Centre de Recherche en Linguistique Appliquée
2022-2023
Leibniz Institute for Astrophysics Potsdam
2014-2022
We estimate the galaxy stellar mass function and density for star-forming quiescent galaxies with 0.2<z<4. construct a deep K<24 sample of 220000 selected using UltraVISTA DR1 data release. Our analysis is based on precise 30-band photometric redshifts. By comparing these redshifts 10800 spectroscopic from zCOSMOS bright faint surveys, we find precision sigma(dz/(1+z))=0.008 at i<22.5 sigma(dz/(1+zs))=0.03 1.5<z<4. derive correct Eddington bias. mass-dependent evolution global populations....
We present the MUSE Hubble Ultra Deep Survey, a mosaic of nine fields covering 90\% entire HUDF region with 10-hour deep exposure time, plus deeper 31-hour in single 1.15 arcmin2 field. The improved observing strategy and advanced data reduction results datacubes sub-arcsecond spatial resolution (0.65 arcsec at 7000 A) accurate astrometry (0.07 rms). compare broadband photometric properties to HST photometry, finding good agreement zeropoint up mAB=28 but an increasing scatter for faint...
Abstract What are the faintest distant galaxies we can see with Hubble Space Telescope ( HST ) now, before launch of James Webb ? This is challenge taken up by Frontier Fields, a Director’s discretionary time campaign and Spitzer to deeper into universe than ever before. The Fields combines power natural gravitational telescopes massive high-magnification clusters produce deepest observations their lensed obtained. Six clusters—Abell 2744, MACSJ0416.1-2403, MACSJ0717.5+3745,...
We introduce Zurich Atmosphere Purge (ZAP), an approach to sky subtraction based on principal component analysis (PCA) that we have developed for the Multi Unit Spectrographic Explorer (MUSE) integral field spectrograph. ZAP employs filtering and data segmentation enhance inherent capabilities of PCA subtraction. Extensive testing shows reduces emission residuals while robustly preserving flux line shapes astronomical sources. The method works in a variety observational situations from...
Processing of raw data from modern astronomical instruments is nowadays often carried out using dedicated software, so-called "pipelines" which are largely run in automated operation. In this paper we describe the reduction pipeline Multi Unit Spectroscopic Explorer (MUSE) integral field spectrograph operated at ESO's Paranal observatory. This a complex machine: it records 1152 separate spatial elements on detectors its 24 units. Efficiently handling such requires sophisticated high degree...
We have used the Institut de Radioastronomie Millimétrique (IRAM) Plateau Bure Interferometer and Expanded Very Large Array to obtain a high-resolution map of CO(6–5) CO(1–0) emission in lensed, star-forming galaxy SMM J2135−0102 at z = 2.32. The kinematics gas are well described by model rotationally supported disk with an inclination-corrected rotation speed, vrot 320 ± 25 km s−1, ratio rotational-to-dispersion support v/σ 3.5 0.2, dynamical mass (6.0 0.5) × 1010 M☉ within radius 2.5 kpc....
Using deep Keck spectroscopy of Lyman break galaxies selected from infrared imaging data taken with WFC3/IR onboard the Hubble Space Telescope, we present new evidence for a reversal in redshift-dependent fraction star forming detectable alpha emission redshift range 6.3 < z 8.8. Our earlier surveys DEIMOS spectrograph demonstrated significant increase line emitting over interval 4 6, particularly intrinsically faint systems which dominate luminosity density. longer wavelength sensitivities...
We present Keck/MOSFIRE observations of UV metal lines in four bright gravitationally-lensed z~6-8 galaxies behind the cluster Abell 1703. The spectrum A1703-zd6, a highly-magnified star forming galaxy with Lyman-alpha redshift z=7.045, reveals confident detection nebular CIV emission line (unresolved FWHM < 125 km/s). are not detected three other galaxies. At z~2-3, is observed just 1% UV-selected presence strong one small sample targeted this paper may indicate hard ionizing spectra more...
We observed the Hubble Deep Field South with new panoramic integral field spectrograph MUSE that we built and just commissioned at VLT. The data cube resulting from 27 hours of integration covers one arcmin^2 view an unprecedented depth a 1 sigma emission line surface brightness limit 1x$10^{-19}$ erg/s/cm$^2$/arcsec$^2$ contains ~90,000 spectra. present combined calibrated cube, perform first-pass analysis sources detected in HDF-S imaging. measured redshifts 189 up to magnitude F814W =...
Extending over three Hubble Space Telescope (HST) cycles, the Frontier Fields (HFF) initiative constitutes largest commitment ever of HST time to exploration distant Universe via gravitational lensing by massive galaxy clusters. Here, we present models mass distribution in six HFF cluster lenses, derived from a joint strong- and weak-lensing analysis anchored total 88 multiple-image systems identified existing data. The resulting maps projected magnification effectively calibrate clusters as...
With the Hubble Frontier Fields program, gravitational lensing has provided a powerful way to extend study of ultraviolet luminosity function (LF) galaxies at $z \sim 6$ down unprecedented magnitude limits. At same time, significant discrepancies between different studies were found very faint end LF. In an attempt understand such disagreements, we present comprehensive assessment uncertainties associated with models and size distribution galaxies. We use end-to-end simulations from source...
We present deep spectroscopy of 17 very low mass (M⋆ ≃ 2.0 × 106–1.4 109 M⊙) and luminosity (MUV −13.7 to −19.9) gravitationally lensed galaxies in the redshift range z 1.5-3.0. Deep rest-frame ultraviolet spectra reveal large equivalent width emission from numerous lines (N iv], O iii], C iv, Si iii]) which are rarely seen individual more massive star-forming galaxies. iii] is detected 16 low-mass systems with widths as 13.5 Å. Nebular iv most extreme emitters, requiring an ionizing source...
We report the detection of extended Lyman-alpha (Lya) haloes around 145 individual star-forming galaxies at redshifts 3 M_{UV}> -22) Lya emitters (LAEs). Using a 2D, two-component decomposition emission assuming circular exponential distributions, we measure scale lengths and luminosities haloes. find that 80% our objects having reliable halo measurements show is significantly more than UV continuum detected by HST (by factor ~4 to >20). The median length in sample ~4.5 kpc. By...
Deep spectroscopic observations of z ≳ 6.5 galaxies have revealed a marked decline with increasing redshift in the detectability Ly α emission. While this may offer valuable insight into end reionization process, it presents challenge to detailed study bright photometrically-selected distant sources now being found via deep Hubble Space Telescope imaging, and particularly those highly magnified viewed through foreground lensing clusters. In paper, we demonstrate validity new way forward...
We use deep Hubble Space Telescope imaging of the Frontier Fields to accurately measure galaxy rest-frame ultraviolet luminosity function (UV LF) in redshift range z ∼ 6–8. combine observations three lensing clusters, A2744, MACS 0416, and 0717, their associated parallel fields select high-redshift dropout candidates. latest models estimate flux magnification effective survey volume combination with completeness simulations performed source plane. report detection 227 candidates at = 6–7 25...
One of the main goals JWST is to study first galaxies in Universe. We present a systematic photometric analysis very distant deep field towards massive lensing cluster SMACS0723. As result, we report discovery two galaxy candidates at $z\sim16$, only $250$ million years after Big Bang. also identify $z\sim 12$ and 6 9-11$. Our search extended out $z\lesssim21$ by combining color information across seven NIRCam NIRISS filters. By modelling Spectral Energy Distributions (SEDs) with...
We present the clump populations detected in 18 lensed galaxies at redshifts 1 to 8.5 within lensing cluster field SMACS0723. The recent JWST Early Release Observations of this poorly known region sky have revealed numerous point-like sources and surrounding their host galaxies, undetected shallower HST images. use multiband photometry model galaxy estimate intrinsic sizes magnitudes stellar clumps. derive optical restframe effective radii from $<$10 100s pc masses ranging $\sim10^5$ $10^9$...
We present a reconstruction of the mass distribution galaxy cluster Abell 1689 at z = 0.18 using detected strong lensing features from deep ACS observations and extensive ground based spectroscopy. Earlier analyses have reported up to 32 multiply imaged systems in this cluster, which only 3 were spectroscopically confirmed. In work, we parametric 34 24 newly determined spectroscopic redshifts, is major step forward building robust model. turn, new data allows more secure identification...
Clusters of galaxies are excellent locations to probe the distribution baryons and dark matter (DM) over a wide range scales. We study sample seven massive, relaxed galaxy clusters with centrally-located brightest cluster (BCGs) at z=0.2-0.3. Using observational tools strong weak gravitational lensing, combined resolved stellar kinematics within BCG, we measure total radial density profile, comprising both baryonic matter, scales ~3-3000 kpc. Lensing-derived mass profiles typically agree...
We present spatially-resolved dynamics for six strongly lensed star-forming galaxies at z=1.7-3.1, each enlarged by a linear magnification factor ~8. Using the Keck laser guide star AO system and OSIRIS integral field unit spectrograph we resolve kinematic morphological detail in our sample with an unprecedented fidelity, some cases achieving spatial resolutions of ~100 pc. With one exception sources have diameters ranging from 1-7 kpc, formation rates 2-40 Msun/yr (uncorrected extinction)...
We discuss the observational properties of a remarkably faint triply-imaged galaxy revealed in deep z-band ACS observation lensing cluster A2218. A well-constrained mass model for cluster, which incorporates outcome recent Keck spectroscopic campaigns, suggests that triple system arises via z>6 source viewed at high magnification (~x25). Optical and IR photometry from HST confirms hypothesis significant discontinuity occurs spectral energy distribution within 9250-9850A. If this break is...
Galaxy cluster Abell 3827 hosts the stellar remnants of four almost equally bright elliptical galaxies within a core radius 10kpc. Such corrugation distribution is very rare, and suggests recent formation by several simultaneous mergers. We map associated dark matter, using new Hubble Space Telescope imaging VLT/MUSE integral field spectroscopy gravitationally lensed system threaded through core. find that each central retains matter halo, but (at least) one these spatially offset from its...
Panchromatic observations of the best candidate HyLIRG from widest Herschel extragalactic imaging survey have led to discovery at least four intrinsically luminous z=2.41 galaxies across a ~100-kpc region - cluster starbursting proto-ellipticals. Via sub-arcsecond interferometric we measured accurate gas and star-formation surface densities. The two brightest span ~3 kpc FWHM in submm/radio continuum CO J=4-3, double that J=1-0. broad line is due partly multitude constituent large rotational...