A5024679457- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Astro and Planetary Science
- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- Calibration and Measurement Techniques
- Planetary Science and Exploration
- Astrophysics and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Pulsars and Gravitational Waves Research
- Space Exploration and Technology
- History and Developments in Astronomy
- CCD and CMOS Imaging Sensors
- Sensor Technology and Measurement Systems
- Optical Wireless Communication Technologies
- Optical Systems and Laser Technology
- Scientific Research and Discoveries
- Scientific Measurement and Uncertainty Evaluation
- Advanced Frequency and Time Standards
- Atmospheric aerosols and clouds
- Soil Moisture and Remote Sensing
European Southern Observatory
2013-2022
European Southern Observatory
2007-2015
Université de Montpellier
2011
Institut National de Physique Nucléaire et de Physique des Particules
2011
Centre National de la Recherche Scientifique
2011
Nanjing University
2011
Atacama Large Millimeter Submillimeter Array
2008
University of Maryland, College Park
2005
University of Liège
2005
Pomona College
2005
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 describe the design, development, and performance of HAWK-I, new High-Acuity Wide-field K-band Imager for ESO's Very Large Telescope, which is equipped with a mosaic four 2 k arrays operates from 0.9-2.4 μm over 0.1´´ pixels. A novel feature use all reflective optics that, together filters excellent throughput detectors high quantum efficiency, has yielded an extremely throughput. Commissioning science verification observations have already delivered variety deep images that demonstrate...
The massive Arches cluster near the Galactic center should be an ideal laboratory for investigating star formation under extreme conditions. But it comes at a high price: is hidden behind several tens of magnitudes visual extinction. Severe crowding requires space or AO-assisted instruments to resolve stellar populations, and even with best interpreting data far from direct. Several investigations using NICMOS most advanced AO imagers on ground revealed overall top-heavy IMF cluster, very...
Nova shells are the remnants of a nova eruption in cataclysmic variable system. By studying their geometry we can better understand physical mechanisms that shape such during eruption. A shell challenges our current understanding these processes is observed around V1425 Aql. It has at least two different components: an inner, symmetric and outer, asymmetric shell, with latter expanding faster than former. The reason for ejecta not clear. We aim to characterise properties differences between...
We present a new integral-field spectroscopic dataset of the central part Orion Nebula (M 42), observed with MUSE instrument at ESO VLT. reduced data public pipeline. The output products are two FITS cubes spatial size ~5.9'x4.9' (corresponding to ~0.76 pc x 0.63 pc) and contiguous wavelength coverage 4595...9366 Angstrom, spatially sampled 0.2". provide versions sampling 1.25 Angstrom 0.85 in dispersion direction. Together variance these files have 75 110 GiB on disk. They represent one...
We use HAWK-I, the recently-commissioned near-IR imager on Yepun (VLT-UT4), to obtain wide-field, high-resolution images of X-ray luminous galaxy cluster XMMU J2235.3-2557 in J and Ks bands, we these build a colour-magnitude diagram galaxies. Galaxies core form tight red sequence with mean colour 1.9 (Vega system). The intrinsic scatter galaxies that lie is similar measured for Coma cluster. slope location can be modelled by passively evolving backwards time. Using simple stellar population...
Two narrow and dense rings (called C1R C2R) were discovered around the Centaur object (10199) Chariklo during a stellar occultation observed on 2013 June 3. Following this discovery, we planned observations of several occultations by Chariklo's system in order to better characterize physical properties ring main body. Here, use 12 successful occulations between 2014 2016. They provide profiles (physical width, opacity, edge structure) constraints radii pole position. Our new are currently...
Two scenarios have been proposed to match the existing observational constraints of object HR 6819. The system could consist a close inner B-type giant plus black hole (BH) binary with an additional Be companion in wide orbit. Alternatively, it be composed stripped B star and Either scenario makes 6819 cornerstone as stellar BH closest Earth, or example important transitional, non-equilibrium phase for stars solid evidence its nature. We aimed distinguish between two Both models predict...
Nova shells are the remnants of a nova eruption in cataclysmic variable system. By studying their geometry we can better understand physical mechanisms that shape them during eruption. A shell challenges our current understanding these processes is observed around V1425 Aql. It has at least two different components: an inner and symmetric shell, outer asymmetric with latter expanding faster than former. The reason behind ejecta not clear. We aim to characterize properties differences between...
We introduce VLT-MUSE observations of the central 2$'\times2'$ (30$\times$30 pc) Tarantula Nebula in Large Magellanic Cloud. The provide an unprecedented spectroscopic census massive stars and ionised gas vicinity R136, young, dense star cluster located NGC 2070, at heart richest star-forming region Local Group. Spectrophotometry radial-velocity estimates nebular (superimposed on stellar spectra) are provided for 2255 point sources extracted from MUSE datacubes, we present radial velocities...
The diffuse intracluster light (ICL) contains a significant fraction of the total stellar mass in clusters galaxies, and contributes roughly equal proportion as hot medium to baryon content clusters. Because potential importance understanding origin ICL context formation evolution structure Universe, field has recently undergone revival both quality quantity observational theoretical investigations. cosmological dimming, work mostly concentrated on low-redshift clusters, but clearly...
Secondary eclipses are a powerful tool to measure directly the thermal emission from extrasolar planets, and constrain their type physical parameters. We started project obtain reliable broad-band measurements of transiting exoplanets. Ground-based high-cadence near-infrared relative photometry was used sub-millimagnitude precision light curve secondary eclipse WASP-4b -- 1.12 M_J hot Jupiter on 1.34 day orbit around G7V star. The data show clear ~10-σdetection planet's at 2.2 μm. calculated...
On the basis of multislit spectroscopy 180 stars in ionising cluster 30 Doradus we present reliable radial velocities for 55 stars. We calculate a velocity dispersion km s-1 and analyse possible influence spectroscopic binaries this rather large dispersion. use numerical simulations to show that observations are consistent with hypothesis all binaries, total mass is ~ . A simple test shows only marginal evidence dynamical segregation which if most likely not due relaxation.
Currently the only technique sensitive to Earth mass planets around nearby stars (that are too close for microlensing) is monitoring of transit time variations transiting extrasolar planets. We search additional in systems hot Neptune GJ 436b, and hot-Jupiter XO-1b, using high cadence observations J Ks bands. New high-precision timing measurements reported: 436b Tc = 2454238.47898 \pm 0.00046 HJD; XO-1b Tc(A) 2454218.83331 0.00114 HJD, Tc(B) 2454222.77539 0.00036 Tc(C) 2454222.77597 0.00039...
Our recent determination of a Salpeter slope for the IMF in field 30 Doradus (Selman and Melnick 2005) appears to be conflict with simple probabilistic counting arguments advanced past support observational claims steeper LMC field. In this paper we re-examine these show by explicit construction that, contrary claims, is expected exactly same as stellar clusters out which was presumably formed. We that current data on mass distribution themselves excellent agreement our model, consistent...
Not all stars exhibiting the optical spectral characteristics of B[e] share same evolutionary stage. The Galactic star MWC 137 is a prime example an object with uncertain classification, previous work suggesting pre- and post-main sequence classification. Our goal to settle this debate provide reliable Integral field spectrograph observations VLT MUSE cluster SH 2-266 are used analyze nature 137. A collimated outflow discovered that geometrically centered on central position in within larger...
We present spectral types for 175 stars in the ionising cluster of 30 Doradus derived from multislit observations 231 stars. Comparison with published classifications 70 common other authors reveals excellent agreement exception a few cases which are discussed detail. Our new raise to 261 total number Dor known types, outside R136. analyse spatial distribution these according their and find evidence mass segregation.
A substantial fraction of the total stellar mass in rich clusters galaxies resides a diffuse intergalactic component usually referred to as intracluster light (ICL). Theoretical models indicate that these stars originate mostly from tidal interaction cluster during assembly history cluster, and significant could have formed situ late infall cold metal-poor gas clouds on cluster. However, also overpredict ICL by margin, something is still not well understood. The make predictions about age...
Context . Nova eruptions occur in cataclysmic variables when enough material has been accreted onto the surface of white dwarf primary. As a consequence, that accumulated until then is expelled into interstellar medium, forming an expanding nova shell around system. Understanding physical process shapes morphology shells essential to fully comprehend how ejection mechanism operates during eruptions. Because its closeness and age, classical RR Pic (Nova 1925) ideal target for studying...
Diffuse Interstellar Bands (DIBs) are non-stellar weak absorption features of unknown origin found in the spectra stars viewed through one or several clouds Medium (ISM). Research DIBs outside Milky Way is currently very limited. Specifically spatially resolved investigations Local Group is, to our knowledge, inexistent. Here, we explore capability high sensitivity Integral Field Spectrograph, MUSE, as a tool map diffuse interstellar bands at distances larger than 100 Mpc. We use MUSE...
Context.About 500 new variable stars enter the General Catalogue of Variable Stars (GCVS) every year. Most them however lack spectroscopic observations, which remains critical for a correct assignement variability type and understanding object.