A5052490271- Astrophysics and Star Formation Studies
- Molecular Spectroscopy and Structure
- Atmospheric Ozone and Climate
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Spectroscopy and Laser Applications
- Advanced Chemical Physics Studies
- Astronomical Observations and Instrumentation
- Calibration and Measurement Techniques
- Atomic and Molecular Physics
- Distributed and Parallel Computing Systems
- Superconducting and THz Device Technology
- Spacecraft and Cryogenic Technologies
- Ionosphere and magnetosphere dynamics
- Galaxies: Formation, Evolution, Phenomena
- SAS software applications and methods
- Astrophysical Phenomena and Observations
- Optical Coatings and Gratings
- Adaptive optics and wavefront sensing
- Gamma-ray bursts and supernovae
- Scientific Measurement and Uncertainty Evaluation
- Advanced Computational Techniques and Applications
- Inorganic Fluorides and Related Compounds
- Thermodynamic properties of mixtures
Université de Toulouse
2015-2024
Centre National de la Recherche Scientifique
2015-2024
Université Toulouse III - Paul Sabatier
2015-2024
Institut de Recherche en Astrophysique et Planétologie
2012-2023
Roche (France)
1998-2018
Laboratoire d'Analyse et d'Architecture des Systèmes
1994-2017
Max Planck Institute for Radio Astronomy
2015
Max Planck Society
2015
Observatoire Midi-Pyrénées
2014
Roche (Switzerland)
2010-2013
<i>Aims. <i/>This paper describes the Heterodyne Instrument for Far-Infrared (HIFI) that was launched onboard ESA's <i>Herschel<i/> Space Observatory in May 2009. <i>Methods. <i/>The instrument is a set of 7 heterodyne receivers are electronically tuneable, covering 480–1250 GHz with SIS mixers and 1410–1910 range hot electron bolometer (HEB) mixers. The local oscillator (LO) subsystem comprises Ka-band synthesizer followed by 14 chains frequency multipliers 2 each band. A pair...
While warm dense gas is prevalent around low-mass protostars, the presence of complex saturated molecules—the chemical inventory characteristic hot cores—has remained elusive in such environments. Here we report results an IRAM 30 m study molecular composition associated with protostar IRAS 16293-2422. Our observations highlight extremely rich organic this source abundant amounts O- and N-bearing molecules as formic acid, HCOOH, acetaldehyde, CH3CHO, methyl formate, CH3OCHO, dimethyl ether,...
Aims. In this paper the calibration and in-orbit performance of Heterodyne Instrument for Far-Infrared (HIFI) is described.
We report the detection of complex molecules (HCOOCH3, HCOOH, and CH3CN), signposts a hot core-like region, toward low-mass Class 0 source NGC 1333 IRAS 4A. This is second protostar in which such have been searched for reported, other being 16293-2422. It therefore likely that compact (a few tens AU) regions dense warm gas, where chemistry dominated by evaporation grain mantles are found, common sources. Given chemical formation timescale much shorter than gas hot-core crossing time, it not...
We report the first detection of doubly-deuterated methanol (CHD2OH), as well firm detections two singly-deuterated isotopomers (CH2DOH and CH3OD), towards solar-type protostar IRAS 16293-2422. From present multifrequency observations, we derive following abundance ratios: , . The total deuterated forms is greater than that its normal hydrogenated counterpart in circumstellar material 16293-2422, a circumstance not previously encountered. Formaldehyde, which thought to be chemical precursor...
We report the first detection of triply-deuterated methanol, with 12 observed transitions, towards low-mass protostar IRAS 16293-2422, as well multifrequency observations 13CH3OH, used to derive column density main isotopomer CH3OH. The derived fractionation ratio [CD3OH]/[CH3OH] averaged on a 10'' beam is 1.4%. Together previous CH2DOH and CHD2OH observations, present CD3OH are consistent formation methanol grain surfaces, if atomic D/H 0.1 0.3 in accreting gas. Such high can be reached...
Complex organic molecules have been observed for decades in the interstellar medium. Some of them might be considered as small bricks macromolecules at base terrestrial life. It is hence particularly important to understand chemistry Solar-like star forming regions. In this article, we present a new observational project: SOLIS (Seeds Of Life Space). This Large Project IRAM-NOEMA interferometer, and its scope image emission several crucial sample regions different evolutionary stage...
Context. Unbiased spectral surveys are powerful tools to study the chemistry and physics of star forming regions, because they can provide a complete census molecular content observed lines probe physical structure source.
We present initial results from the Herschel GT key program: observations of EXtra-Ordinary Sources (HEXOS) and outline promise potential spectral surveys with Herschel/HIFI. The HIFI instrument offers unprecedented sensitivity, as well continuous coverage across gaps imposed by atmosphere, opening up a largely unexplored wavelength regime to high-resolution spectroscopy. show spectrum Orion KL between 480 560 GHz 1.06 1.115 THz. From these data, we confirm that separately measures dust...
Formamide (NH2CHO), the simplest possible amide, has recently been suggested to be a central species in synthesis of metabolic and genetic molecules, chemical basis life. In this Letter, we report first detection formamide protostar, IRAS 16293−2422, which may similar Sun solar system progenitor. The data combine spectra from millimeter submillimeter TIMASSS survey with recent, more sensitive observations at IRAM 30 m telescope. With an abundance relative H2 ∼10−10, appears as abundant...
Context. Water is a primordial species in the emergence of life, and comets may have brought large fraction to Earth form oceans. To understand evolution water from first stages star formation planets comets, HDO/H2O ratio powerful diagnostic.
Context. Modern versions of the Miller-Urey experiment claim that formamide (NH2CHO) could be starting point for formation metabolic and genetic macromolecules. Intriguingly, is indeed observed in regions forming solar-type stars external galaxies.
Evidence is mounting that the small bodies of our Solar System, such as comets and asteroids, have at least partially inherited their chemical composition from first phases System formation. It then appears molecular complexity these most likely related to earliest stages star therefore important characterize understand how evolution changes with solar-type protostellar evolution. We present here Large Program "Astrochemical Surveys At IRAM" (ASAI). Its goal carry out unbiased millimeter...
Subarcsecond images of the rotational line emissions CCH, CS, H2CO, and CH3OH have been obtained toward low-mass protostar IRAS 04368+2557 in L1527 as one early science projects Atacama Large Millimeter/submillimeter Array. The intensity distributions CCH CS show a double-peaked structure along edge-on envelope with dip position, whereas those H2CO are centrally peaked. By analyzing position–velocity diagrams envelope, found to reside mainly where gas is infalling conservation its angular...
Complex organic molecules (COMs) are considered to be crucial molecules, since they connected with chemistry, at the basis of terrestrial life. More pragmatically, which in principle difficult synthesize harsh interstellar environments and, therefore, a test for astrochemical models. Current models assume that several COMs synthesized on lukewarm grain surfaces (≳30–40 K) and released gas phase dust temperatures ≳100 K. However, recent detections ≲20 K demonstrate we still need important...
ABSTRACT We report the first evidence of a hot corino in Bok globule. This is based on ALMA observations 1.2 mm band toward low-mass Class 0 protostar IRAS 19347+0727 B335. Saturated complex organic molecules (COMs), CH 3 CHO, HCOOCH , and NH 2 are detected compact region within few 10 au around protostar. Additionally, OCH C H 5 OH, CN, COCH tentatively detected. Carbon-chain related molecules, CCH c-C also found this source, whose distributions extended over scale 100 au. On other hand,...
Complex organic molecules have previously been discovered in solar-type protostars, raising the questions of where and how they form envelope. Possible formation mechanisms include grain mantle evaporation, interaction outflow with its surroundings, and/or impact UV/X-rays inside cavities. In this Letter we present first interferometric observations two complex molecules, CH3CN HCOOCH3, toward protostar IRAS 16293-2422. The images show that emission originates from compact regions centered...
We present a survey of the formaldehyde emission in sample eight Class 0 protostars obtained with IRAM and JCMT millimeter telescopes. The range energies observed transitions allows us to probe physical chemical conditions across protostellar envelopes. data have been analyzed three different methods increasing level sophistication. first analyze LTE approximation, derive rotational temperatures between 11 40 K, column densities 1 cm-2. Second, we use LVG code higher kinetic temperatures, 30...
Context : Despite the low cosmic abundance of deuterium (D/H ~ 1e-5), large degrees fractionation in molecules are observed star forming regions with enhancements that can reach 13 orders magnitude, which current models have difficulties to account for. Aims Multi-isotopologue observations a very powerful constraint for chemical models. The aim our is understand processes abundances methanol and formaldehyde low-mass protostellar envelopes (gas-phase ? chemistry on grain surfaces ?) better...
High resolution line spectra of star-forming regions are mines information: they provide unique clues to reconstruct the chemical, dynamical, and physical structure observed source. We present first results from <i>Herschel<i/> key project "Chemical <i>HErschel<i/> Surveys Star forming regions", CHESS. report discuss observations towards five CHESS targets, one outflow shock spot four protostars with luminosities bewteen 20 2 × 10<sup>5<sup/> : L1157-B1, IRAS 16293-2422, OMC2-FIR4, AFGL...
We present the first results of unbiased survey L1157-B1 bow shock, obtained with HIFI in framework key program Chemical <i>HErschel<i/> Survey Star forming regions (CHESS). The L1157 outflow is driven by a low-mass Class 0 protostar and considered prototype so-called chemically active outflows. bright blue-shifted shock B1 ideal laboratory for studying link between hot (~1000–2000 K) component traced H<sub>2<sub/> IR-emission cold (~10–20 swept-up material. main aim to trace warm gas...
We discuss the detection of absorption by interstellar hydrogen fluoride (HF) along sight line to submillimeter continuum sources W49N and W51. have used Herschel's HIFI instrument in dual beam switch mode observe 1232.4762 GHz J = 1 - 0 HF transition upper sideband band 5a receiver. detected foreground toward both over a wide range velocities. Optically thin components were on lines, allowing us measure as opposed obtain lower limit column density for first time. As previous observations...