A5061168955- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Molecular Spectroscopy and Structure
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Galaxies: Formation, Evolution, Phenomena
- Atmospheric Ozone and Climate
- Astronomical Observations and Instrumentation
- Advanced Combustion Engine Technologies
- Spectroscopy and Laser Applications
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Atomic and Molecular Physics
- Radio Astronomy Observations and Technology
- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Scientific Research and Discoveries
- Solar and Space Plasma Dynamics
- Space Exploration and Technology
- Superconducting and THz Device Technology
- High-pressure geophysics and materials
- Advanced Chemical Physics Studies
- Diamond and Carbon-based Materials Research
- Statistical Methods and Applications
- History and Developments in Astronomy
Institut de Planétologie et d'Astrophysique de Grenoble
1996-2024
Université Grenoble Alpes
2015-2023
Centre National de la Recherche Scientifique
2014-2023
CEA Paris-Saclay
2012-2021
CEA Paris-Saclay - Etablissement de Saclay
2005-2021
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2011-2020
Université Paris Cité
2011-2020
Institut de Recherche sur les Lois Fondamentales de l'Univers
2011-2020
Astrophysique, Instrumentation et Modélisation
2011-2020
Délégation Paris 7
2010-2019
We summarize the first results from Gould Belt survey, obtained toward Aquila Rift and Polaris Flare regions during 'science demonstration phase' of Herschel. Our 70-500 micron images taken in parallel mode with SPIRE PACS cameras reveal a wealth filamentary structure, as well numerous dense cores embedded filaments. Between ~ 350 500 prestellar 45-60 Class 0 protostars can be identified field, while unbound starless no are observed field. The core mass function (CMF) derived for region...
<i>Context. <i/>Thanks to its excellent 5100 m high site in Chajnantor, the Atacama Pathfinder Experiment (APEX) systematically explores southern sky at submillimeter wavelengths, both continuum and spectral line emission. Studying emission from interstellar dust is essential locating highest density regions medium, deriving their masses, column densities, structures, large-scale morphologies. In particular, early stages of (massive) star formation remain poorly understood, mainly because...
We present the first results from science demonstration phase for Hi-GAL survey, <i>Herschel<i/> key program that will map inner Galactic plane of Milky Way in 5 bands. outline our data reduction strategy and some highlights on two observed 2° × tiles approximately centered at <i>l<i/> = 30° 59°. The regions are extremely rich intense highly structured extended emission which shows a widespread organization filaments. Source SEDs can be built hundreds objects fields, physical parameters...
We provide a first look at the results of Herschel Gould Belt survey toward IC5146 molecular cloud and present preliminary analysis filamentary structure in this region. The column density map, derived from our 70-500 micron data, reveals complex network filaments, confirms that these filaments are main birth sites prestellar cores. analyze profiles 27 show underlying radial fall off as r^{-1.5} to r^{-2.5} large radii. Our result is seem be characterized by narrow distribution widths having...
Hi-GAL, the Herschel infrared Galactic Plane Survey, is an Open Time Key Project of Space Observatory. It will make unbiased photometric survey inner plane by mapping a 2° wide strip in longitude range ∣l∣ < 60° five wavebands between 70 μm and 500 μm. The aim Hi-GAL to detect earliest phases formation molecular clouds high-mass stars use optimum combination wavelength coverage, sensitivity, strategy, speed deliver homogeneous census star-forming regions cold structures interstellar medium....
We present first results from the Herschel Gould Belt survey for B211/L1495 region in Taurus molecular cloud. Thanks to their high sensitivity and dynamic range, images reveal structure of dense, star-forming filament B211 with unprecedented detail, along presence striations perpendicular generally oriented magnetic field direction as traced by optical polarization vectors. Based on column density dust temperature maps derived data, we find that radial profile approaches a power-law behavior...
We present a detailed 1.2 mm continuum and CS spectral line study of large sample 69 massive star forming regions in very early stages evolution, most them prior to building up an ultracompact H II region. The data show zoo different morphologies give information on the spatial distributions, masses, column densities, average densities whole sample. Fitting radial intensity profiles shows that three parameters are needed describe distribution sources: constant emission from center out few...
This review examines the state-of-the-art knowledge of high-mass star and massive cluster formation, gained from ambitious observational surveys, which acknowledge multi-scale characteristics these processes. After a brief overview theoretical models main open issues, we present searches for evolutionary phases first among high-luminosity sources more recently young protostars elusive prestellar cores. We then introduce most likely scenario emphasizes link formation to cloud formation....
For many years feedback processes generated by OB-stars in molecular clouds, including expanding ionization fronts, stellar winds, or UV-radiation, have been proposed to trigger subsequent star formation. However, hydrodynamic models radiation and gravity show that UV-illumination has little no impact on the global dynamical evolution of cloud. The Rosette cloud, irradiated NGC2244 cluster, is a template region for triggered star-formation, we investigated its spatial density structure...
Thermal images of cold dust in the Central Molecular Zone Milky Way, obtained with far-infrared cameras on board Herschel satellite, reveal a ∼3 × 107 M☉ ring dense and clouds orbiting Galactic center. Using simple toy model, an elliptical shape having semi-major axes 100 60 pc is deduced. The major axis this inclined by about 40° respect to plane sky oriented perpendicular Bar. appears trace system stable x2 orbits predicted for barred potential. Sgr A⋆ displaced geometrical center symmetry...
The formation of massive stars is a highly complex process in which it not clear whether the star-forming gas global gravitational collapse or an equilibrium state, supported by turbulence. By studying one most and dense regions Galaxy at distance less than 3 kpc, filament containing well-known sources DR21 DR21(OH), we expect to find observational signatures that allow discriminate between two views. We use molecular line data from our 13CO 1-0, CS 2-1, N2H+ 1-0 survey Cygnus X region...
The origin and possible universality of the stellar initial mass function (IMF) is a major issue in astrophysics. One main objectives Herschel Gould Belt Survey to clarify link between prestellar core (CMF) IMF. We present discuss derived from data for large population cores discovered with SPIRE PACS Aquila Rift cloud complex at d ~ 260 pc. detect total 541 starless entire ~11 deg^2 area field imaged 70-500 micron SPIRE/PACS. Most these appear be gravitationally bound, thus nature. Our...
(Abridged) We present the first public release of high-quality data products (DR1) from Hi-GAL, {\em Herschel} infrared Galactic Plane Survey. Hi-GAL is keystone a suite continuum surveys near-IR to radio, and covers five wavebands at 70, 160, 250, 350 500 micron, encompassing peak spectral energy distribution cold dust for 8 < T 50K. This inner Milky Way in longitude range 68{\deg} > l -70{\deg} |b|<1{\deg} latitude strip. Photometric maps have been produced with ROMAGAL pipeline, that...
A key parameter to the description of all star formation processes is density structure gas. In this Letter, we make use probability distribution functions (PDFs) Herschel column maps Orion B, Aquila, and Polaris, obtained with Gould Belt survey (HGBS). We aim understand which physical influence PDF shape, signatures. The PDFs B (Aquila) show a lognormal for low densities until AV ∼ 3 (6), power-law tail high densities, consistent ρ∝r−2 profile equivalent spherical distribution. broadened by...
We present a complete 1.3 mm continuum mapping survey of the embedded young stellar objects (YSOs) in Taurus molecular cloud. have also imaged several isolated Bok globules, as well protostellar Perseus cluster. Our maps, taken with IRAM 30 m telescope and MPIfR bolometer arrays, are sensitive to column density structure sources on spatial scales ranging from 1 500-5 000 AU > 15 000-50 AU. For envelopes mapped Taurus, results roughly consistent predictions self-similar inside-out collapse...
We present the results of 1.3-mm continuum mapping observations eight pre-stellar cores, taken with IRAM 30-m telescope equipped 19-channel MPIfR bolometer array. The new data, which were obtained in 'on-the-fly' mode, have higher angular resolution and sensitivity than previous surveys, reaching an rms noise level ̃ 3–9 mJy per 13-arcsec beam. study supports conclusions our James Clerk Maxwell Telescope (JCMT) survey suggests that, contrast some theoretical predictions, most cores flat...
Aims.Our current knowledge of high-mass star formation is mainly based on follow-up studies bright sources found by IRAS, and thus biased against its earliest phases, inconspicuous at infrared wavelengths. We therefore started searching, in an unbiased way the closest star-forming complexes, for analogs low-mass pre-stellar cores class 0 protostars.
Our PACS and SPIRE images of the Aquila Rift part Polaris Flare regions, taken during science demonstration phase <i>Herschel<i/> discovered fascinating, omnipresent filamentary structures that appear to be physically related compact cores. We briefly describe a new multi-scale, multi-wavelength source extraction method used detect objects measure their parameters in our images. All extracted starless cores (541 302 Polaris) form long very narrow filaments. With its combination far-IR...
We present the initial highlights of HOBYS key program, which are based on <i>Herschel<i/> images Rosette molecular complex and maps RCW120 H ii region. Using both SPIRE at 250/350/500 <i>μ<i/>m PACS 70/160 or 100/160 <i>μ<i/>m, survey provides an unbiased complete census intermediate- to high-mass young stellar objects, some not detected by <i>Spitzer<i/>. Key core properties, such as bolometric luminosity mass (as derived from spectral energy distributions), used constrain their...
The relative importance of primordial molecular cloud fragmentation versus large-scale accretion still remains to be assessed in the context massive core/star formation. Studying kinematics dense gas surrounding massive-star progenitors can tell us extent which flow material impacts growth mass star-forming cores. Here we present a comprehensive dataset 5500(+/-800) Msun infrared dark SDC335.579-0.272 (hereafter SDC335) exhibits network cold, dense, parsec-long filaments. Atacama Large...
Context.The Cygnus X region is one of the richest star formation sites in Galaxy. There a long-standing discussion about whether chance superposition several complexes along line sight or single coherent complex at distance 1.5 to 2 kpc.
We present the first Herschel PACS and SPIRE results of Vela C molecular complex in far-infrared submillimetre regimes at 70, 160, 250, 350, 500 um, spanning peak emission cold prestellar or protostellar cores. Column density multi-resolution analysis (MRA) differentiates into five distinct sub-regions. Each sub-region displays differences their column temperature probability distribution functions (PDFs), particular, PDFs `Centre-Ridge' `South-Nest' sub-regions appear stark contrast to each...
We present a power spectrum analysis of the Herschel-SPIRE observations Polaris flare, high Galactic latitude cirrus cloud midway between diffuse and molecular phases. The SPIRE images flare reveal for first time structure interstellar medium down to 0.01 parsec over 10 square degrees region. These exceptional highlight highly filamentary clumpy even in regions map. shows that is well described by single law with an exponent -2.7 +- 0.1 at all scales from 30" 8 degrees. That slope dust...
The earliest phases of clustered star formation and the origin stellar initial mass function (IMF) are currently much debated. In order to constrain IMF, we investigated internal relative motions starless condensations protostars previously detected by us in dust continuum at 1.2mm L1688 protocluster Ophiuchus molecular cloud complex. have a spectrum resembling IMF therefore likely representative stages protocluster. We carried out detailed line observations, including some N2H+(1-0)...