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101. TIMASSS : The IRAS16293-2422 Millimeter And Submillimeter Spectral Survey: Tentative Detection of Deuterated Methyl Formate (DCOOCH3)

Author

Sandrine Bottinelli, Alain Castets, Charlotte Vastel, Emmanuel Caux, K. Demyk, Claudine Kahane, Cecilia Ceccarelli, Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, 010304 chemical physics, Methyl formate, Analytical chemistry, Rotational transition, FOS: Physical sciences, Astronomy and Astrophysics, Excitation temperature, Astrophysics, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, chemistry.chemical_compound, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Deuterium, chemistry, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Protostar, Isotopologue, Methanol, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], 010303 astronomy & astrophysics, Line (formation)
Abstract

International audience; High deuterium fractionation is observed in various types of environment such as prestellar cores, hot cores and hot corinos. It has proven to be an efficient probe to study the physical and chemical conditions of these environments. The study of the deuteration of different molecules helps us to understand their formation. This is especially interesting for complex molecules such as methanol and bigger molecules for which it may allow to differentiate between gas-phase and solid-state formation pathways. Methanol exhibits a high deuterium fractionation in hot corinos. Since CH3OH is thought to be a precursor of methyl formate we expect that deuterated methyl formate is produced in such environments. We have searched for the singly-deuterated isotopologue of methyl formate, DCOOCH3, in IRAS 16293-2422, a hot corino well-known for its high degree of methanol deuteration. We have used the IRAM/JCMT unbiased spectral survey of IRAS 16293-2422 which allows us to search for the DCOOCH3 rotational transitions within the survey spectral range (80-280 GHz, 328-366 GHz). The expected emission of deuterated methyl formate is modelled at LTE and compared with the observations.} We have tentatively detected DCOOCH3 in the protostar IRAS 16293-2422. We assign eight lines detected in the IRAM survey to DCOOCH3. Three of these lines are affected by blending problems and one line is affected by calibration uncertainties, nevertheless the LTE emission model is compatible with the observations. A simple LTE modelling of the two cores in IRAS 16293-2422, based on a previous interferometric study of HCOOCH3, allows us to estimate the amount of DCOOCH3 in IRAS 16293-2422. Adopting an excitation temperature of 100 K and a source size of 2\arcsec and 1\farcs5 for the A and B cores, respectively, we find that N(A,DCOOCH3) = N(B,DCOOCH3) ~ 6.10^14 /cm2. The derived deuterium fractionation is ~ 15%, consistent with values for other deuterated species in this source and much greater than that expected from the deuterium cosmic abundance. DCOOCH3, if its tentative detection is confirmed, should now be considered in theoretical models that study complex molecule formation and their deuteration mechanisms. Experimental work is also needed to investigate the different chemical routes leading to the formation of deuterated methyl formate.

Published
2010
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102. Chemical modeling of L183 (L134N): an estimate of the ortho/para H_2 ratio

Author

Chris H. Greene, S. Schlemmer, E. Bayet, Cecilia Ceccarelli, Charlotte Vastel, Aurore Bacmann, Laurent Pagani, Viatcheslav Kokoouline, Edouard Hugo, Renshui Peng, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Univ Toulouse UPS, Ctr Etud Spatiale Rayonnements, F-31062 Toulouse 9, France, Centre Etud Spatiale Rayonnements Toulouse, CNRS INSU, UMR 5187, F-31028 Toulouse 4, France, UMR 5187 Toulouse, Technologies et systèmes d'information pour les agrosystèmes (UR TSCF), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire Aimé Cotton (LAC), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Department of Physics, University of Central Florida (UCF), University of Central Florida [Orlando], Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Laboratoire de Radioastronomie (LRA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany, Univ Cologne, Inst Phys 1, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), I. Physikalisches Institut [Köln], Universität zu Köln = University of Cologne, Department of Physics [Orlando] (UCF | Physics), University of Central Florida [Orlando] (UCF), Joint Institute for Laboratory Astrophysics (JILA), National Institute of Standards and Technology [Gaithersburg] (NIST)-University of Colorado [Boulder], Dept of physics and astrophysics, University College of London [London] (UCL), Caltech Submillimeter Observatory, California Institute of Technology (CALTECH), École normale supérieure - Paris (ENS Paris), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École normale supérieure - Cachan (ENS Cachan), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Universität zu Köln, Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Abundance (chemistry), Chemical process modeling, ISM: structure, FOS: Physical sciences, Context (language use), Astrophysics, ISM: individual objects: L183, 01 natural sciences, Molecular physics, ISM: clouds, ISM: abundances, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Reaction rate, Trihydrogen cation, 0103 physical sciences, Isotopologue, 010306 general physics, 010303 astronomy & astrophysics, Dissociative recombination, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], astrochemistry, Astrophysics (astro-ph), Astronomy and Astrophysics, molecular processes, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Space and Planetary Science, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], ISM: individual objects : L183, Order of magnitude
Abstract

International audience; Context: The high degree of deuteration observed in some prestellar cores depends on the ortho-to-para H2 ratio through the H3+ fractionation. Aims: We want to constrain the ortho/para H2 ratio across the L183 prestellar core. This is required to correctly describe the deuteration amplification phenomenon in depleted cores such as L183 and to relate the total (ortho+para) H2D+ abundance to the sole ortho-H2D+ column density measurement. Methods: To constrain this ortho/para H2 ratio and derive its profile, we make use of the N2D^+/N2H+ ratio and of the ortho-H2D+ observations performed across the prestellar core. We use two simple chemical models limited to an almost totally depleted core description. New dissociative recombination and trihydrogen cation-dihydrogen reaction rates (including all isotopologues) are presented in this paper and included in our models. Results: We estimate the H2D+ ortho/para ratio in the L183 cloud, and constrain the H2 ortho/para ratio: we show that it varies across the prestellar core by at least an order of magnitude, being still very high (≈0.1) in most of the cloud. Our time-dependent model indicates that the prestellar core is presumably older than 1.5-2 × 105 years but that it may not be much older. We also show that it has reached its present density only recently and that its contraction from a uniform density cloud can be constrained. Conclusions: A proper understanding of deuteration chemistry cannot be attained without taking into account the whole ortho/para family of molecular hydrogen and trihydrogen cation isotopologues as their relations are of utmost importance in the global scheme. Tracing the ortho/para H2 ratio should also place useful constraints on the dynamical evolution of prestellar cores. Appendices A and B are only available in electronic form at http://www.aanda.org

Published
2009
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103. The Herschel-Heterodyne Instrument for the Far-Infrared (HIFI): instrument and pre-launch testing

Author

Michel Perault, René Liseau, Hubregt J. Visser, C. Kramer, Rudolf Schieder, Do Kester, L. Ravera, Jon Kawamura, Anthony Murphy, Bob Kruizenga, Xander Tielens, Fabrice Herpin, Nicolas Biver, Douwe Beintema, Thijs de Graauw, Willem Jellema, Jean-Michel Krieg, P. Planesas, Peer Zaal, L. Dubbeldam, John Ward, Claudia Comito, Emmanuel Dartois, Klaas Wildeman, Patrick W. Morris, Rolf Güsten, David Teyssier, John Pearson, Sabine Phillip, Rafael Moreno, N. Honingh, Gert de Lange, Willem Luinge, R. Shipman, Harald Franz Arno Merkel, H. Jacobs, Albert Naber, Frank Schmuelling, Steve Lord, Bengt Larsson, Adwin Boogert, H. Aarts, Volker Ossenkopf, Charlotte Vastel, Kees Wafelbakker, Teun M. Klapwijk, Christian Leinz, Ian Delorme, Pieter Dieleman, Piotr Orleanski, Anna DiGiorgio, Mirek Rataj, Anthony Marston, Sergey Cherednichenko, Frank Helmich, Roonan Higgins, Jürgen Stutzki, W. M. Laauwen, Albrecht de Jonge, M. Fich, Jesús Martín-Pintado, Arnold O. Benz, Thomas G. Phillips, Ryszard Szczerba, Odile Coeur-Joly, T. Klein, Francois Boulanger, Peter Roelfsema, Paolo Saraceno, K. Edwards, R. Huisman, Nick Whyborn, Micheal Olberg, Jacob Kooi, Emmanuel Caux, Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, California Institute of Technology (CALTECH), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology [Gothenburg, Sweden], Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), SRON Netherlands Institute for Space Research (SRON), Institut de biologie et chimie des protéines [Lyon] (IBCP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Department of physical chemistry, Uppsala University, Max-Planck-Institut für Radioastronomie (MPIFR), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Institute of Medical Technology and Tampere University Hospital, University of Tampere [Finland], Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), KOSMA, I. Physikalisches Institut, Universität zu Köln, Institut de Microélectronique, Electromagnétisme et Photonique (IMEP), Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique de Grenoble (INPG)-Université Joseph Fourier - Grenoble 1 (UJF), CSIRO Materials Sciences and Engineering, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Instituto de Estructura de la Materia (IEM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Onsala Space Observatory, Chalmers University of Technology [Göteborg], Department of Physics and Astronomy [Leicester], University of Leicester, Laboratoire de Radioastronomie (LRA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Photonics Centre, University College Cork (UCC), Dept Pathol & Microbiol, Université de Montréal (UdeM)-Faculté de médecine vétérinaire, Oschmann, Jacobus M., Jr., de Graauw, Mattheus W. M., MacEwen, Howard A., Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Nice Sophia Antipolis (1965 - 2019) (UNS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Universität zu Köln = University of Cologne, Université Joseph Fourier - Grenoble 1 (UJF)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Heterodyne, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], business.industry, Frequency band, Local oscillator, Bolometer, Superheterodyne receiver, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 020206 networking & telecommunications, 02 engineering and technology, 01 natural sciences, 7. Clean energy, Radio spectrum, law.invention, Optics, Far infrared, law, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Ka band, business, 010303 astronomy & astrophysics, Remote sensing
Abstract

International audience; This paper describes the Heterodyne Instrument for the Far-Infrared (HIFI), to be launched onboard of ESA's Herschel Space Observatory, by 2008. It includes the first results from the instrument level tests. The instrument is designed to be electronically tuneable over a wide and continuous frequency range in the Far Infrared, with velocity resolutions better than 0.1 km/s with a high sensitivity. This will enable detailed investigations of a wide variety of astronomical sources, ranging from solar system objects, star formation regions to nuclei of galaxies. The instrument comprises 5 frequency bands covering 480-1150 GHz with SIS mixers and a sixth dual frequency band, for the 1410-1910 GHz range, with Hot Electron Bolometer Mixers (HEB). The Local Oscillator (LO) subsystem consists of a dedicated Ka-band synthesizer followed by 7 times 2 chains of frequency multipliers, 2 chains for each frequency band. A pair of Auto-Correlators and a pair of Acousto-Optic spectrometers process the two IF signals from the dual-polarization front-ends to provide instantaneous frequency coverage of 4 GHz, with a set of resolutions (140 kHz to 1 MHz), better than < 0.1 km/s. After a successful qualification program, the flight instrument was delivered and entered the testing phase at satellite level. We will also report on the pre-flight test and calibration results together with the expected in-flight performance.

Published
2008
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104. Depletion and low gas temperature in the L183 (=L134N) prestellar core: the N2H^+-N2D+ tool

Author

Laurent Pagani, Aurore Bacmann, Sylvie Cabrit, Charlotte Vastel, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Coupling, Astronomy and Astrophysics, Context (language use), Astrophysics, 7. Clean energy, 01 natural sciences, Computational physics, Core (optical fiber), Deuterium, Space and Planetary Science, 0103 physical sciences, Radiative transfer, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010306 general physics, 010303 astronomy & astrophysics, Hyperfine structure, Beam (structure), Line (formation)
Abstract

International audience; Context: The study of pre-stellar cores (PSCs) suffers from a lack of undepleted species to trace the physical properties of the gas in their very dense inner parts. Aims: We carry out detailed modelling of N2H+ and N2D+ cuts across the L183 main core to evaluate the depletion of these species and their usefulness as a probe of physical conditions in PSCs. Methods: We have developed a non-LTE (NLTE) Monte-Carlo code treating the 1D radiative transfer of both N2H+ and N2D^+, making use of recently published collisional coefficients with He between individual hyperfine levels. The code includes line overlap between hyperfine transitions. An extensive set of core models is calculated and compared with observations. Special attention is paid to the issue of source coupling to the antenna beam. Results: The best-fitting models indicate that i) gas in the core center is very cold (7 ± 1 K) and thermalized with dust; ii) depletion of N2H+ does occur, starting at densities 5-7×105 cm-3 and reaching a factor of 6^+13-3 in abundance; iii) deuterium fractionation reaches ~70% at the core center; and iv) the density profile is proportional to r-1 out to ~4000 AU, and to r-2 beyond. Conclusions: Our NLTE code could be used to (re-)interpret recent and upcoming observations of N2H+ and N2D+ in many pre-stellar cores of interest, to obtain better temperature and abundance profiles. Based on observations made with the IRAM 30-m and the CSO 10-m. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain). Table 1, Figs. 5 and 6 are only available in electronic form at http://www.aanda.org

Published
2007
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105. Hyperfine structure of the cyanomethyl radical (CH2CN) in the L1544 prestellar core

Author

Charlotte Vastel, Rafael Bachiller, Bertrand Lefloch, and Satoshi Yamamoto

Subjects
Physics, Core (optical fiber), Astrochemistry, Space and Planetary Science, Radiative transfer, Molecule, Astronomy and Astrophysics, Spectral resolution, Atomic physics, Hyperfine structure, Line (formation), Dense core
Abstract

The L1544 prestellar core has been observed as part of the ASAI IRAM Large Program at 3 mm. These observations led to the detection of many complex molecules. In this Letter we report the detection of the cyanomethyl radical for the first time in a prototypical prestellar core, which is possible through the high sensitivity of the IRAM EMIR receiver. A complex structure in which we suspect the presence of the hyperfine transitions of the ortho and para forms is observed thanks to the high spectral resolution of ~50 kHz. We computed all transition frequencies and line intensities for all transitions including satellite hyperfine components for the ortho and para forms of CH2 CN at the frequencies observed by ASAI. We report the first detection of the fine and hyperfine structure of the ortho and para forms of the cyanomethyl radical at ~101 GHz, resolved in this cold dense core.

Published
2015
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106. Deuterium enhancement in H3+ in pre-stellar cores

Author

Charlotte, Vastel, T G, Phillips, P, Caselli, C, Ceccarelli, and L, Pagani

Abstract

Deuterium enhancement of monodeuterated species has been recognized for more than 30 years as a result of chemical fractionation that results from the difference in zero-point energies of deuterated and hydrogenated molecules. The key reaction is the deuteron exchange in the reaction between HD, the reservoir of deuterium in dark interstellar clouds, and the H3+ molecular ion, leading to the production of H2D+ molecule, and the low temperature in dark interstellar clouds favours this production. Furthermore, the presence of multiply deuterated species have incited our group to proceed further and consider the subsequent reaction of H2D+ with HD, leading to D2H+, which can further react with HD to produce D3+. In pre-stellar cores, where CO was found to be depleted, this production should be increased as CO would normally destroy H3+. The first model including D2H+ and D3+ predicted that these molecules should be as abundant as H2D+. The first detection of the D2H+ was made possible by the recent laboratory measurement for the frequency of the fundamental line of para-D2H+. Here, we present observations of H2D+ and D2H+ towards a sample of dark clouds and pre-stellar cores and show how the distribution of ortho-H2D+ (1(1,0)-1(1,1)) can trace the deuterium factory in pre-stellar cores. We also present how future instrumentation will improve our knowledge concerning the deuterium enhancement of H3+.

Published
2006

107. Ground State Rotational Lines of Doubly Deuterated Ammonia as Tracers of the Physical Conditions and Chemistry of Cold Interstellar Medium

Author

Evelyne Roueff, Thomas G. Phillips, Charlotte Vastel, Dariusz C. Lis, Maryvonne Gerin, California Institute of Technology, Downs Laboratory of Physics, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Interstellar medium, Caltech Submillimeter Observatory, Space and Planetary Science, Molecular cloud, Astronomy and Astrophysics, Isotopologue, Astrophysics, Excitation temperature, Atacama Large Millimeter Array, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Submillimeter Array, Line (formation)
Abstract

International audience; We report the first detection of the NKAKC=111-->000 and 110-->000 ground state rotational lines of o-ND2H at 335.5 and 388.7 GHz, obtained in the Lynds 1689N, Barnard 1, and Lynds 1544 molecular clouds using the Caltech Submillimeter Observatory (CSO). The submillimeter ND2H lines have moderate opacities and simple hyperfine patterns, which allow accurate determination of the excitation temperature, H2 volume density, and molecular column density. Both transitions have high critical densities. The 389 GHz line, in particular, traces molecular material with densities above a few × 106 cm-3. The strong 389 GHz ND2H emission in LDN 1689N implies a high fraction of dense gas in this source, ~30%, as compared to ~15% in B1 and LDN 1544. All these regions are sites of strong molecular depletion and heavy deuteration. Nonaccreting molecules, H+3 and its isotopologues, are difficult to study, but in the sources studied here it appears that ammonia and its isotopologues are not completely frozen out, even in the high density gas. In the well-studied case of LDN 1544, the volume probed by the ND2H emission has densities of ~106-107 cm-3, within the range where the ``complete freezeout'' has been predicted to occur. The critical density of the 389 GHz ND2H line is close to that of the 309 GHz ND3 line. Observations of these two transitions thus provide an accurate measure of the [ND3]/[ND2H] fractionation ratio in the very dense gas. The [ND3]/[ND2H] ratio in LDN 1689N (~3%) appears lower than the values measured in B1 and LDN 1544 (~7%-10%), indicating that different chemical processes may be at work in these environments. The submillimeter lines of deuteroammonia are relatively strong and detectable from good sites, such as Mauna Kea or Chajnantor. Interferometric observations of these lines with the Submillimeter Array (SMA), and subsequently the Atacama Large Millimeter Array (ALMA), will provide new opportunities to study the physics and chemistry of cold, dense ISM, where most molecules are depleted onto dust grains.

Published
2006
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108. The puzzling detection of D_2CO in the molecular cloud L1689N

Author

Emmanuel Caux, Cecilia Ceccarelli, Alain Castets, Aggm Tielens, Charlotte Vastel, A. C. A. Boogert, and Laurent Loinard

Subjects
Physics, Space and Planetary Science, Molecular cloud, Ophiuchus, Molecule, Cold storage, Astronomy and Astrophysics, Astrophysics, Gas phase
Abstract

We present new observations of the D_2CO emission towards the small cloud L1689N in the ρ Ophiuchus complex. We surveyed five positions, three being a cut across a shock site and two probing the quiescent gas of the molecular cloud. We detected D_2CO emission in the first three positions. The measured [D_2CO] /[ H2CO] is about 3%, whereas it is ≤2% in the quiescent gas. We discuss the implications of these new observations, which suggest that the bulk of the D_2CO molecules is stored in grain mantles, and removed from the cold storage by the shock at the interface between the outflowing and quiescent gas. We review the predictions of the published models proposed to explain the observed high deuteration of formaldehyde. They fall in two basic schemes: gas phase and grain surface chemistry. None of the reviewed models is able to account for the observed [D_2CO] /[H_2CO] abundance ratio. A common characteristics shared by the models is apparently that all underestimate the atomic [D]/[H] ratio in the accreting gas.

Published
2002

109. First astronomical use of multiplexed transition edge bolometers

Author

Erich N. Grossman, Kent D. Irwin, Dominic J. Benford, Charlotte Vastel, S. A. Khan, George M. Voellmer, F. Pajot, J. A. Chervenak, Johannes G. Staguhn, Bruno Maffei, C. Rioux, Carl D. Reintsema, T. A. Ames, J. C. Renault, S. H. Moseley, Richard A. Shafer, Thomas G. Phillips, Porter, F. S., McCammon, D., Galeazi, M., and Stahle, C. K.

Subjects
Physics, Spectrometer, Physics::Instrumentation and Detectors, business.industry, Bolometer, Astrophysics::Instrumentation and Methods for Astrophysics, Physics::Optics, Astrophysics::Cosmology and Extragalactic Astrophysics, First light, Submillimetre astronomy, law.invention, Caltech Submillimeter Observatory, Interferometry, Optics, law, Spectral resolution, Transition edge sensor, business, Astrophysics::Galaxy Astrophysics
Abstract

We present performance results based on the first astronomical use of multiplexed superconducting bolometers. The Fabry-Perot Interferometer Bolometer Research Experiment (FIBRE) is a broadband submillimeter spectrometer that achieved first light in June 2001 at the Caltech Submillimeter Observatory (CSO). FIBRE'S detectors are superconducting transition edge sensor (TES) bolometers read out by a SQUID multiplexer. The Fabry-Perot uses a low resolution grating to order sort the incoming light. A linear bolometer array consisting of 16 elements detects this dispersed light, capturing 5 orders simultaneously from one position on the sky. With tuning of the Fabry-Perot over one free spectral range, a spectrum covering Δλ/λ= 1/7 at a resolution of δλ/λ ≈ 1/1200 can be acquired. This spectral resolution is sufficient to resolve Doppler-broadened line emission from external galaxies. FIBRE operates in the 350 µm and 450 µm bands. These bands cover line emission from the important star formation tracers neutral carbon [Cl] and carbon monoxide (CO). We have verified that the multiplexed bolometers are photon noise limited even with the low power present in moderate resolution spectrometry.

Published
2002
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110. A CHEMICAL VIEW OF PROTOSTELLAR-DISK FORMATION IN L1527

Author

Charlotte Vastel, Yoko Oya, Audrey Coutens, Shigehisa Takakuwa, Nagayoshi Ohashi, Emmanuel Caux, Satoshi Yamamoto, Nami Sakai, Bertrand Lefloch, Tomoya Hirota, Ana López-Sepulcre, Cecilia Ceccarelli, Yuri Aikawa, Hsi-Wei Yen, Claudine Kahane, Takeshi Sakai, Sandrine Bottinelli, and Yoshimasa Watanabe

Subjects
Physics, Angular momentum, Stars, Space and Planetary Science, Protostar, Astronomy, Astronomy and Astrophysics, Radius, Astrophysics, Submillimeter Array, Stellar evolution, Line (formation), Envelope (waves)
Abstract

Subarcsecond images of the rotational line emissions of CCH, CS, H2CO, and CH3OH have been obtained toward the low-mass protostar IRAS 04368+2557 in L1527 as one of the early science projects of the Atacama Large Millimeter/submillimeter Array. The intensity distributions of CCH and CS show a double-peaked structure along the edge-on envelope with a dip toward the protostar position, whereas those of H2CO and CH3OH are centrally peaked. By analyzing the position-velocity diagrams along the envelope, CCH and CS are found to reside mainly in the envelope, where the gas is infalling with conservation of its angular momentum. They are almost absent inward of the centrifugal barrier (a half of the centrifugal radius). Although H2CO exists in the infalling rotating envelope, it also resides in the disk component inside the centrifugal barrier to some extent. On the other hand, CH3OH seems to exist around the centrifugal barrier and in the disk component. Hence, the drastic chemical change occurs at the centrifugal barrier. A discontinuous infalling motion as well as the gas-grain interaction would be responsible for the chemical change. This result will put an important constraint on initial chemical compositions for chemical evolution of protostellar disks.

Published
2014
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111. WATER DEUTERIUM FRACTIONATION IN THE INNER REGIONS OF TWO SOLAR-TYPE PROTOSTARS

Author

Claudine Kahane, Vianney Taquet, Ana López-Sepulcre, Audrey Coutens, Cecilia Ceccarelli, Charlotte Vastel, and Roberto Neri

Subjects
Heavy water, Physics, Astrochemistry, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Type (model theory), Astrophysics - Astrophysics of Galaxies, chemistry.chemical_compound, Stars, chemistry, Deuterium, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Protostar, Molecule, Line (formation)
Abstract

The [HDO]/[H2O] ratio is a crucial parameter for probing the history of water formation. So far, it has been measured for only three solar type protostars and yielded different results, possibly pointing to a substantially different history in their formation. In the present work, we report new interferometric observations of the HDO 4 2,2 - 4 2,3 line for two solar type protostars, IRAS2A and IRAS4A, located in the NGC1333 region. In both sources, the detected HDO emission originates from a central compact unresolved region. Comparison with previously published interferometric observations of the H218$O 3 1,3 - 2 2,0 line shows that the HDO and H$_2$O lines mostly come from the same region. A non-LTE LVG analysis of the HDO and H218$O line emissions, combined with published observations, provides a [HDO]/[H2O] ratio of 0.3 - 8 % in IRAS2A and 0.5 - 3 % in IRAS4A. First, the water fractionation is lower than that of other molecules such as formaldehyde and methanol in the same sources. Second, it is similar to that measured in the solar type protostar prototype, IRAS16293-2422, and, surprisingly enough, larger than that measured in NGC1333 IRAS4B. {The comparison of the measured values towards IRAS2A and IRAS4A with the predictions of our gas-grain model GRAINOBLE gives similar conclusions to those for IRAS 16293, arguing that these protostars {share} a similar chemical history, although they are located in different clouds., Accepted for publication to ApJL. 6 pages, 2 figures

Published
2013
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112. Reversal of infall in SgrB2(M) revealed by Herschel/HIFI observations of HCN lines at THz frequencies

Author

P. J. Encrenaz, Sébastien Maret, Edwin A. Bergin, Emmanuel Caux, Shanshan Yu, Thomas G. Phillips, John Gill, Neil Trappe, Javier R. Goicoechea, M. Perault, José Cernicharo, D. Johnstone, Peter Schilke, Stephan Schlemmer, T. A. Bell, Maryvonne Gerin, Volker Ossenkopf, S.-L. Qin, Claudia Comito, P. F. Goldsmith, Martin Emprechtinger, S. D. Lord, H. Gupta, Dariusz C. Lis, Thomas F. Giesen, Rene Plume, Patrick W. Morris, Marie-Lise Dubernet, Charlotte Vastel, Cecilia Ceccarelli, Jesús Martín-Pintado, L. Nordh, Pierrick Martin, J. Stutzki, R. Rolffs, Karl M. Menten, Fabien Daniel, Rolf Guesten, W. D. Latter, Goutam Chattopadhyay, W. Baechtold, Geoffrey A. Blake, C. Joblin, Gary J. Melnick, H. S. P. Mueller, H. W. Yorke, J. A. Murphy, W. D. Langer, Michael Olberg, Nathan R. Crockett, Rafael Bachiller, Eric Herbst, J. C. Pearson, M. C. Diez-Gonzalez, Jonas Zmuidzinas, F. F. S. van der Tak, S. Wang, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Astronomy, Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Experimental Physics, 010504 meteorology & atmospheric sciences, Opacity, ISM: structure, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, COLOGNE DATABASE, STAR-FORMATION, 0103 physical sciences, Radiative transfer, Astrophysics::Solar and Stellar Astrophysics, Isotopologue, FACILITY, OUTFLOW, Emission spectrum, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, ISM: kinematics and dynamics, CDMS, stars: formation, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Star formation, Molecular cloud, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Accretion (astrophysics), ISM: molecules, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), MOLECULAR-SPECTROSCOPY, submillimeter: ISM, Vector field, Astrophysics::Earth and Planetary Astrophysics, ISM: individual objects: SgrB2(M), B2, HIFI
Abstract

To investigate the accretion and feedback processes in massive star formation, we analyze the shapes of emission lines from hot molecular cores, whose asymmetries trace infall and expansion motions. The high-mass star forming region SgrB2(M) was observed with Herschel/HIFI (HEXOS key project) in various lines of HCN and its isotopologues, complemented by APEX data. The observations are compared to spherically symmetric, centrally heated models with density power-law gradient and different velocity fields (infall or infall+expansion), using the radiative transfer code RATRAN. The HCN line profiles are asymmetric, with the emission peak shifting from blue to red with increasing J and decreasing line opacity (HCN to H$^{13}$CN). This is most evident in the HCN 12--11 line at 1062 GHz. These line shapes are reproduced by a model whose velocity field changes from infall in the outer part to expansion in the inner part. The qualitative reproduction of the HCN lines suggests that infall dominates in the colder, outer regions, but expansion dominates in the warmer, inner regions. We are thus witnessing the onset of feedback in massive star formation, starting to reverse the infall and finally disrupting the whole molecular cloud. To obtain our result, the THz lines uniquely covered by HIFI were critically important., A&A, HIFI special issue, accepted

Published
2010
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113. Herschelobservations of EXtra-Ordinary Sources (HEXOS): The Terahertz spectrum of Orion KL seen at high spectral resolution

Author

Thomas F. Giesen, S.-L. Qin, S. D. Lord, Alexandre Karpov, Rene Plume, Neil Trappe, Fabien Daniel, G. A. Blake, C. Joblin, Patrick W. Morris, R. Güsten, Emmanuel Caux, Peter Schilke, Rudolf Schieder, M. Perault, C. Comito, J. Stutzki, Bruce Bumble, José Cernicharo, E. A. Bergin, Stephan Schlemmer, P. J. Encrenaz, Frank Helmich, Marie-Lise Dubernet, Holger S. P. Müller, Shanshan Yu, E. Falgarone, W. D. Langer, W. D. Latter, S. Wang, Thomas G. Phillips, D. C. Lis, Pierrick Martin, S. Cabrit, David A. Neufeld, P. F. Goldsmith, H. W. Yorke, D. Johnstone, Gary J. Melnick, Karl M. Menten, Paul Hartogh, N. Honingh, Pieter R. Roelfsema, J.-M. Krieg, T. A. Bell, Volker Ossenkopf, H. Gupta, Sébastien Maret, J. Kawamura, Nathan R. Crockett, A. C. A. Boogert, Jacob Kooi, Martin Emprechtinger, Charlotte Vastel, Eric Herbst, Cecilia Ceccarelli, Aggm Tielens, J. R. Goicoechea, J. C. Pearson, J. A. Murphy, Jonas Zmuidzinas, F. F. S. van der Tak, Maryvonne Gerin, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Faure, Alexandre, and Astronomy

Subjects
Experimental Physics, 010504 meteorology & atmospheric sciences, Terahertz radiation, FOS: Physical sciences, Astrophysics, ISM: clouds, 7. Clean energy, 01 natural sciences, 0103 physical sciences, Emission spectrum, Spectral resolution, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS, ISM: general, 0105 earth and related environmental sciences, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], astrochemistry, Spectrum (functional analysis), Astronomy and Astrophysics, ISM: molecules, Space observatory, On board, Astrophysics - Solar and Stellar Astrophysics, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, submillimeter: ISM
Abstract

We present the first high spectral resolution observations of Orion KL in the frequency ranges 1573.4 - 1702.8 GHz (band 6b) and 1788.4 - 1906.8 GHz (band 7b) obtained using the HIFI instrument on board the Herschel Space Observatory. We characterize the main emission lines found in the spectrum, which primarily arise from a range of components associated with Orion KL including the hot core, but also see widespread emission from components associated with molecular outflows traced by H2O, SO2, and OH. We find that the density of observed emission lines is significantly diminished in these bands compared to lower frequency Herschel/HIFI bands., Accepted for publication in the Herschel HIFI special issue of Astronomy and Astrophysics Letters, 5 pages, 3 figures

Published
2010
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114. The CHESS spectral survey of star forming regions: Peering into the protostellar shock L1157-B1. II. Shock dynamics

Author

K. Schuster, M. Benedettini, F. Gueth, Gary J. Melnick, F. F. S. van der Tak, G. de Lange, S. D. Lord, D. C. Lis, P. J. Encrenaz, S. Pacheco, Emmanuel Caux, Asunción Fuente, Brunella Nisini, N. Crimier, Patrick Hennebelle, M. H. D. van der Wiel, Serena Viti, G. A. Blake, Valentine Wakelam, Peter Schilke, Paolo Saraceno, P. Hily-Blant, José Cernicharo, Frank Maiwald, Karine Demyk, Colin Borys, Friedrich Wyrowski, C. Kramer, E. Falgarone, T. Jacq, Berengere Parise, A. Klotz, A. Lorenzani, M. Salez, A. C. A. Boogert, P. Siegel, Imran Mehdi, Jesús Martín-Pintado, Rafael Bachiller, Cecilia Ceccarelli, David A. Neufeld, P. F. Goldsmith, Aggm Tielens, E. A. Bergin, Sébastien Maret, Laurent Pagani, Charlotte Vastel, T. A. Bell, Volker Ossenkopf, Th. Henning, J. C. Pearson, Thomas G. Phillips, Sylvie Cabrit, Bertrand Lefloch, Juan R. Pardo, Alain Baudry, Harold W. Yorke, Alain Castets, J. Stutzki, Aurore Bacmann, Bengt Larsson, Audrey Coutens, Frank Helmich, C. Comito, Claudine Kahane, Mihkel Kama, Y. Delorme, Maryvonne Gerin, Paola Caselli, Claudio Codella, J. H. Wunsch, Adam Walters, W. D. Langer, Carsten Dominik, R. Lai, Sandrine Bottinelli, Eric Herbst, Low Energy Astrophysics (API, FNWI), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Kapteyn Astronomical Institute, Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Roma (OAR), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Laboratoire de Radioastronomie (LRA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Ohio State University [Columbus] (OSU), Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Radioastronomie (MPIFR), Instituto de RadioAstronomía Milimétrica (IRAM), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, École normale supérieure - Paris (ENS Paris), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Civilisations atlantiques & Archéosciences (C2A), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ministère de la Culture et de la Communication (MCC)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Université de Nantes - UFR Histoire, Histoire de l'Art et Archéologie (UFR HHAA), Université de Nantes (UN)-Université de Nantes (UN), Harvard University [Cambridge]-Smithsonian Institution, Université Nice Sophia Antipolis (... - 2019) (UNS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Consiglio Nazionale delle Ricerche (CNR), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Osservatorio di Astrofisica di Roma (OAR), Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS)-Université de Nantes - UFR Histoire, Histoire de l'Art et Archéologie (UFR HHAA), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Faure, Alexandre, Université de Nantes - UFR Histoire, Histoire de l'Art et Archéologie (UFR HHAA), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Ministère de la Culture et de la Communication (MCC), and Smithsonian Institution-Harvard University [Cambridge]

Subjects
DATABASE, Astronomy, LINE EMISSION, Flux, Astrophysics, ISM: ets and outflows, 01 natural sciences, 7. Clean energy, ISM: individual objects: L1157, 0103 physical sciences, PROGRAM, Protostar, 14. Life underwater, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, QB, Line (formation), Physics, stars: formation, 010308 nuclear & particles physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], ISM: molecules, EVOLUTION, Shock (mechanics), 13. Climate action, Space and Planetary Science, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, 1157 MOLECULAR OUTFLOW, Outflow, METHANOL, Magnetohydrodynamics, SUBMILLIMETER, Order of magnitude, Excitation
Abstract

International audience; Context. The outflow driven by the low-mass class 0 protostar L1157 is the prototype of the so-called chemically active outflows. The bright bowshock B1 in the southern outflow lobe is a privileged testbed of magneto-hydrodynamical (MHD) shock models, for which dynamical and chemical processes are strongly interdependent. Aims: We present the first results of the unbiased spectral survey of the L1157-B1 bowshock, obtained in the framework of the key program “Chemical HErschel Surveys of star forming regions” (CHESS). The main aim is to trace the warm and chemically enriched gas and to infer the excitation conditions in the shock region. Methods: The CO 5-4 and o-H2O 110-101 lines have been detected at high-spectral resolution in the unbiased spectral survey of the HIFI-band 1b spectral window (555-636 GHz), presented by Codella et al. in this volume. Complementary ground-based observations in the submm window help establish the origin of the emission detected in the main-beam of HIFI and the physical conditions in the shock. Results: Both lines exhibit broad wings, which extend to velocities much higher than reported up to now. We find that the molecular emission arises from two regions with distinct physical conditions : an extended, warm (100 K), dense (3 × 105 cm-3) component at low-velocity, which dominates the water line flux in Band 1; a secondary component in a small region of B1 (a few arcsec) associated with high-velocity, hot (>400 K) gas of moderate density ((1.0-3.0) × 104 cm-3), which appears to dominate the flux of the water line at 179μm observed with PACS. The water abundance is enhanced by two orders of magnitude between the low- and the high-velocity component, from 8 × 10-7 up to 8 × 10-5. The properties of the high-velocity component agree well with the predictions of steady-state C-shock models. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Published
2010
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116. Sulfur-bearing Species Tracing the Disk/Envelope System in the Class I Protostellar Source Elias 29.

Author

Yoko Oya, Ana López-Sepulcre, Nami Sakai, Yoshimasa Watanabe, Aya E. Higuchi, Tomoya Hirota, Yuri Aikawa, Takeshi Sakai, Cecilia Ceccarelli, Bertrand Lefloch, Emmanuel Caux, Charlotte Vastel, Claudine Kahane, and Satoshi Yamamoto

Subjects
ACCRETION disks, HIGH temperatures, SPECIES, ROTATIONAL motion, MOTION
Abstract

We observed the Class I protostellar source Elias 29 with the Atacama Large Millimeter/submillimeter Array. We detected CS, SO, 34SO, SO2, and SiO line emissions in a compact component concentrated near the protostar, and a ridge component separated from the protostar by 4″ (∼500 au). The former component is abundant in SO and SO2, but deficient in CS. The abundance ratio SO/CS is as high as at the protostar, which is even higher than that in the outflow-shocked region of L1157 B1. However, organic molecules (HCOOCH3, CH3OCH3, CCH, and c-C3H2) are deficient in Elias 29. We attribute this deficiency in organic molecules and richness in SO and SO2 to the evolved nature of the source or the relatively high dust temperature (≳20 K) in the parent cloud of Elias 29. The SO and SO2 emissions trace rotation around the protostar. Assuming a highly inclined configuration (i ≥ 65°; 0° for a face-on configuration) and Keplerian motion for simplicity, the protostellar mass is estimated to be (0.8–1.0) . The 34SO and SO2 emissions are asymmetric in their spectra; the blueshifted components are weaker than the redshifted ones. Although this may be attributed to the asymmetric molecular distribution, other possibilities are also discussed. [ABSTRACT FROM AUTHOR]

Published
2019
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117. Molecular Cloud Cores with High Deuterium Fractions: Nobeyama Mapping Survey

Author

Di Li, Hiroko Shinnaga, Mark Thompson, Mika Juvela, Siyi Feng, Ryo Kandori, Quang Nguyen Luong, Jinhua He, Charlotte Vastel, Isabelle Ristorcelli, Takeshi Sakai, Ken'ichi Tatematsu, Xing Lu, Somnath Dutta, Sheng-Yuan Liu, L. Viktor Tóth, Tie Liu, Ke Wang, Jungha Kim, James Di Francesco, O. Fehér, Dipen Sahu, Patricio Sanhueza, Gary A. Fuller, Hee-Weon Yi, Kee-Tae Kim, Yuefang Wu, Naomi Hirano, Neal J. Evans, Miju Kang, Tomoya Hirota, David Eden, J. X. Ge, Gwanjeong Kim, Satoshi Ohashi, Minho Choi, Jeong-Eun Lee, and Department of Physics

Subjects
Physics, Star formation, Young stellar object, Molecular cloud, Continuum (design consultancy), FOS: Physical sciences, Velocity dispersion, Astronomy and Astrophysics, Astrophysics, 115 Astronomy, Space science, Astrophysics - Astrophysics of Galaxies, Deuterium, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), interstellar clouds, Emission spectrum, QC, Line (formation), QB
Abstract

We present the results of on-the-fly mapping observations of 44 fields containing 107 SCUBA-2 cores in the emission lines of molecules, N$_2$H$^+$, HC$_3$N, and CCS at 82$-$94 GHz using the Nobeyama 45-m telescope. This study aimed at investigating the physical properties of cores that show high deuterium fractions and might be close to the onset of star formation. We found that the distributions of the N$_2$H$^+$ and HC$_3$N line emissions are approximately similar to that of 850-$\mu$m dust continuum emission, whereas the CCS line emission is often undetected or is distributed in a clumpy structure surrounding the peak position of the 850-$\mu$m dust continuum emission. Occasionally (12%), we observe the CCS emission which is an early-type gas tracer toward the young stellar object, probably due to local high excitation. Evolution toward star formation does not immediately affect nonthermal velocity dispersion., Comment: 45 pages, 15 figures, ApJS, in press

118. Seeds of Life in Space (SOLIS). III. Zooming Into the Methanol Peak of the Prestellar Core L1544.

Author

Anna Punanova, Paola Caselli, Siyi Feng, Ana Chacón-Tanarro, Cecilia Ceccarelli, Roberto Neri, Francesco Fontani, Izaskun Jiménez-Serra, Charlotte Vastel, Luca Bizzocchi, Andy Pon, Anton I. Vasyunin, Silvia Spezzano, Pierre Hily-Blant, Leonardo Testi, Serena Viti, Satoshi Yamamoto, Felipe Alves, Rafael Bachiller, and Nadia Balucani

Subjects
CENTROIDAL Voronoi tessellations, METHANOL, SUBSONIC flow, FLOW velocity, LOCAL thermodynamic equilibrium
Abstract

Toward the prestellar core L1544, the methanol (CH3OH) emission forms an asymmetric ring around the core center, where CH3OH is mostly in solid form, with a clear peak at 4000 au to the northeast of the dust continuum peak. As part of the NOEMA Large Project SOLIS (Seeds of Life in Space), the CH3OH peak has been spatially resolved to study its kinematics and physical structure and to investigate the cause behind the local enhancement. We find that methanol emission is distributed in a ridge parallel to the main axis of the dense core. The centroid velocity increases by about 0.2 km s−1 and the velocity dispersion increases from subsonic to transonic toward the central zone of the core, where the velocity field also shows complex structure. This could be an indication of gentle accretion of material onto the core or the interaction of two filaments, producing a slow shock. We measure the rotational temperature and show that methanol is in local thermodynamic equilibrium (LTE) only close to the dust peak, where it is significantly depleted. The CH3OH column density, Ntot(CH3OH), profile has been derived with non-LTE radiative transfer modeling and compared with chemical models of a static core. The measured Ntot(CH3OH) profile is consistent with model predictions, but the total column densities are one order of magnitude lower than those predicted by models, suggesting that the efficiency of reactive desorption or atomic hydrogen tunneling adopted in the model may be overestimated; or that an evolutionary model is needed to better reproduce methanol abundance. [ABSTRACT FROM AUTHOR]

Published
2018
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119. The TOP-SCOPE Survey of Planck Galactic Cold Clumps: Survey Overview and Results of an Exemplar Source, PGCC G26.53+0.17

Author

Tie Liu, Kee-Tae Kim, Mika Juvela, Ke Wang, Ken’ichi Tatematsu, James Di Francesco, Sheng-Yuan Liu, Yuefang Wu, Mark Thompson, Gary Fuller, David Eden, Di Li, I. Ristorcelli, Sung-ju Kang, Yuxin Lin, D. Johnstone, J. H. He, P. M. Koch, Patricio Sanhueza, Sheng-Li Qin, Q. Zhang, N. Hirano, Paul F. Goldsmith, Neal J. Evans II, Glenn J. White, Minho Choi, Chang Won Lee, L. V. Toth, Steve Mairs, H.-W. Yi, Mengyao Tang, Archana Soam, N. Peretto, Manash R. Samal, Michel Fich, Harriet Parsons, Jinghua Yuan, Chuan-Peng Zhang, Johanna Malinen, George J. Bendo, A. Rivera-Ingraham, Hong-Li Liu, Jan Wouterloot, Pak Shing Li, Lei Qian, Jonathan Rawlings, Mark G. Rawlings, Siyi Feng, Yuri Aikawa, S. Akhter, Dana Alina, Graham Bell, J.-P. Bernard, Andrew Blain, Rebeka Bőgner, L. Bronfman, D.-Y. Byun, Scott Chapman, Huei-Ru Chen, M. Chen, Wen-Ping Chen, X. Chen, Xuepeng Chen, A. Chrysostomou, Giuliana Cosentino, M. R. Cunningham, K. Demyk, Emily Drabek-Maunder, Yasuo Doi, C. Eswaraiah, Edith Falgarone, O. Fehér, Helen Fraser, Per Friberg, G. Garay, J. X. Ge, W. K. Gear, Jane Greaves, X. Guan, Lisa Harvey-Smith, Tetsuo HASEGAWA, J. Hatchell, Yuxin He, C. Henkel, T. Hirota, W. Holland, A. Hughes, E. Jarken, Tae-Geun Ji, Izaskun Jimenez-Serra, Miju Kang, Koji S. Kawabata, Gwanjeong Kim, Jungha Kim, Jongsoo Kim, Shinyoung Kim, B.-C. Koo, Woojin Kwon, Yi-Jehng Kuan, K. M. Lacaille, Shih-Ping Lai, C. F. Lee, J.-E. Lee, Y.-U. Lee, Dalei Li, Hua-bai Li, N. Lo, John A. P. Lopez, Xing Lu, A-Ran Lyo, D. Mardones, A. Marston, P. McGehee, F. Meng, L. Montier, Julien Montillaud, T. Moore, O. Morata, Gerald H. Moriarty-Schieven, S. Ohashi, Soojong Pak, Geumsook Park, R. Paladini, Kate M Pattle, Gerardo Pech, V.-M. Pelkonen, K. Qiu, Zhi-Yuan Ren, John Richer, M. Saito, Takeshi Sakai, H. Shang, Hiroko Shinnaga, Dimitris Stamatellos, Y.-W. Tang, Alessio Traficante, Charlotte Vastel, S. Viti, Andrew Walsh, Bingru Wang, Hongchi Wang, Junzhi Wang, D. Ward-Thompson, Anthony Whitworth, Ye Xu, J. Yang, Yao-Lun Yang, Lixia Yuan, A. Zavagno, Guoyin Zhang, H.-W. Zhang, Chenlin Zhou, Jianjun Zhou, Lei Zhu, Pei Zuo, Chao Zhang, Department of Physics, Shanghai Astronomical Observatory [Shanghai] (SHAO), Chinese Academy of Sciences [Beijing] (CAS), Korea Astronomy and Space Science Institute (KASI), Okayama University, University of Helsinki, University of New South Wales [Sydney] (UNSW), Peking University [Beijing], Department of Mechanical and Aerospace Engineering [Victoria]], Monash University [Clayton], King‘s College London, National Astronomical Observatories [Beijing] (NAOC), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7 Canada, Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, Polar Research Institute of China, Polar Research Institute of China (PRIC)-UAPS, Center for Northeast Asian Studies, Tohoku University [Sendai], Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, SLAC National Accelerator Laboratory (SLAC), Stanford University, School of Physics and Astronomy [Cardiff], Cardiff University, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), University of Cologne, Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Department of Earth and Planetary Sciences [Kobe], Kobe University, Department of Zoology, Auburn University (AU), Departamento de Astronomia (DAS), State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering [Nanjing] (HYDRO-LAB), Hohai University, Swinburne University of Technology (Hawthorn campus), Tokyo University of Science [Tokyo], Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Institute of Vertebrate Paleontology and Paleoanthropology, SUPA School of Physics and Astronomy [University of St Andrews], University of St Andrews [Scotland]-Scottish Universities Physics Alliance (SUPA), National Astronomical Observatory of Japan (NAOJ), Royal Institute of Technology [Stockholm] (KTH ), Queen Mary University of London (QMUL), National Taiwan Normal University (NTNU), National Tsing Hua University [Hsinchu] (NTHU), Div Life Sci, Lab Proteome Anal & Mol Physiol, Gyeongsang Natl Univ, Centre d'Etudes Lasers Intenses et Applications (CELIA), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Bordeaux (UB), foreign laboratories (FL), CERN [Genève], Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire d'Ingénierie des Matériaux de Bretagne (LIMATB), Université de Bretagne Sud (UBS)-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université de Brest (UBO)-Université de Brest (UBO), Department of Physics and Astronomy [UCL London], University College of London [London] (UCL), Department of Anthropology [University of Toronto], University of Toronto, Jeremiah Horrocks Institute for Mathematics, Physics and Astronomy [Preston], University of Central Lancashire [Preston] (UCLAN), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire de Mécanique de Lille - FRE 3723 (LML), Université de Lille, Sciences et Technologies-Ecole Centrale de Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Harvard University [Cambridge], Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), NASA-California Institute of Technology (CALTECH), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université de Brest (UBO), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université de Lille, Sciences et Technologies-Centrale Lille-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Harvard University

Subjects
FOS: Physical sciences, Astrophysics, F500, INITIAL CONDITIONS, LINE-PROFILES, 01 natural sciences, ISM: clouds, ISM: abundances, STAR-FORMATION, Protein filament, Gravitation, symbols.namesake, INFRARED DARK CLOUD, surveys, 0103 physical sciences, DENSE GAS, Infrared dark cloud, Planck, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS, QC, QB, Physics, abundances [ISM], ISM: kinematics and dynamics, CLERK MAXWELL TELESCOPE, Spectral index, formation [stars], stars: formation, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Star formation, Molecular cloud, LARGE-SCALE, Astronomy and Astrophysics, 115 Astronomy, Space science, Astrophysics - Astrophysics of Galaxies, GOULD BELT, FILAMENTARY MOLECULAR CLOUDS, kinematics and dynamics [ISM], Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), symbols, Outflow, FRAGMENTATION, clouds [ISM]
Abstract

The low dust temperatures (, Comment: Accepted for publication in the ApJS

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120. Misaligned Rotations of the Envelope, Outflow, and Disks in the Multiple Protostellar System of VLA 1623–2417: FAUST. III

Author

Satoshi Ohashi, Claudio Codella, Nami Sakai, Claire J. Chandler, Cecilia Ceccarelli, Felipe Alves, Davide Fedele, Tomoyuki Hanawa, Aurora Durán, Cécile Favre, Ana López-Sepulcre, Laurent Loinard, Seyma Mercimek, Nadia M. Murillo, Linda Podio, Yichen Zhang, Yuri Aikawa, Nadia Balucani, Eleonora Bianchi, Mathilde Bouvier, Gemma Busquet, Paola Caselli, Emmanuel Caux, Steven Charnley, Spandan Choudhury, Nicolas Cuello, Marta De Simone, Francois Dulieu, Lucy Evans, Siyi Feng, Francesco Fontani, Logan Francis, Tetsuya Hama, Eric Herbst, Shingo Hirano, Tomoya Hirota, Muneaki Imai, Andrea Isella, Izaskun Jímenez-Serra, Doug Johnstone, Claudine Kahane, Romane Le Gal, Bertrand Lefloch, Luke T. Maud, Maria Jose Maureira, Francois Menard, Anna Miotello, George Moellenbrock, Shoji Mori, Riouhei Nakatani, Hideko Nomura, Yasuhiro Oba, Ross O’Donoghue, Yuki Okoda, Juan Ospina-Zamudio, Yoko Oya, Jaime Pineda, Albert Rimola, Takeshi Sakai, Dominique Segura-Cox, Yancy Shirley, Brian Svoboda, Vianney Taquet, Leonardo Testi, Charlotte Vastel, Serena Viti, Naoki Watanabe, Yoshimasa Watanabe, Arezu Witzel, Ci Xue, Bo Zhao, Satoshi Yamamoto, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Star formation, Astronomy and Astrophysics, Interstellar matter, Astrophysics::Cosmology and Extragalactic Astrophysics, Interstellar molecules, Molecules, Formació d'estels, Young stellar objects, Protostars, Stellar jets, Space and Planetary Science, Circumstellar disks, Interstellar medium, [SDU]Sciences of the Universe [physics], Astrophysics::Solar and Stellar Astrophysics, Matèria interstel·lar, Astrophysics::Earth and Planetary Astrophysics, Molècules, Astrophysics::Galaxy Astrophysics, Astrochemistry
Abstract

We report a study of the low-mass Class 0 multiple system VLA 1623AB in the Ophiuchus star-forming region, using H13CO+ (J = 3–2), CS (J = 5–4), and CCH (N = 3–2) lines as part of the ALMA Large Program FAUST. The analysis of the velocity fields revealed the rotation motion in the envelope and the velocity gradients in the outflows (about 2000 au down to 50 au). We further investigated the rotation of the circumbinary VLA 1623A disk, as well as the VLA 1623B disk. We found that the minor axis of the circumbinary disk of VLA 1623A is misaligned by about 12° with respect to the large-scale outflow and the rotation axis of the envelope. In contrast, the minor axis of the circumbinary disk is parallel to the large-scale magnetic field according to previous dust polarization observations, suggesting that the misalignment may be caused by the different directions of the envelope rotation and the magnetic field. If the velocity gradient of the outflow is caused by rotation, the outflow has a constant angular momentum and the launching radius is estimated to be 5–16 au, although it cannot be ruled out that the velocity gradient is driven by entrainments of the two high-velocity outflows. Furthermore, we detected for the first time a velocity gradient associated with rotation toward the VLA 16293B disk. The velocity gradient is opposite to the one from the large-scale envelope, outflow, and circumbinary disk. The origin of its opposite gradient is also discussed.

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121. L483: Warm Carbon-chain Chemistry Source Harboring Hot Corino Activity.

Author

Yoko Oya, Nami Sakai, Yoshimasa Watanabe, Aya E. Higuchi, Tomoya Hirota, Ana López-Sepulcre, Takeshi Sakai, Yuri Aikawa, Cecilia Ceccarelli, Bertrand Lefloch, Emmanuel Caux, Charlotte Vastel, Claudine Kahane, and Satoshi Yamamoto

Subjects
INTERSTELLAR medium, OPTICAL properties, PROTOSTARS, STAR formation, PROTOPLANETARY disks, STELLAR evolution, PLANETARY atmospheres
Abstract

The Class 0 protostar, L483, has been observed in various molecular lines in the 1.2 mm band at a subarcsecond resolution with ALMA. An infalling–rotating envelope is traced by the CS line, while a very compact component with a broad velocity width is observed for the CS, SO, HNCO, NH2CHO, and HCOOCH3 lines. Although this source is regarded as the warm carbon-chain chemistry (WCCC) candidate source at a 1000 au scale, complex organic molecules characteristic of hot corinos such as NH2CHO and HCOOCH3 are detected in the vicinity of the protostar. Thus, both hot corino chemistry and WCCC are seen in L483. Although such a mixed chemical character source has been recognized as an intermediate source in previous single-dish observations, we here report the first spatially resolved detection. A kinematic structure of the infalling–rotating envelope is roughly explained by a simple ballistic model with a protostellar mass of 0.1–0.2 and a radius of the centrifugal barrier (half of the centrifugal radius) of 30–200 au, assuming an inclination angle of 80° (0° for face-on). The broad-line emission observed in the above molecules most likely comes from the disk component inside the centrifugal barrier. Thus, a drastic chemical change is seen around the centrifugal barrier. [ABSTRACT FROM AUTHOR]

Published
2017
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122. DISCOVERY OF A HOT CORINO IN THE BOK GLOBULE B335.

Author

Muneaki Imai, Nami Sakai, Yoko Oya, Ana López-Sepulcre, Yoshimasa Watanabe, Cecilia Ceccarelli, Bertrand Lefloch, Emmanuel Caux, Charlotte Vastel, Claudine Kahane, Takeshi Sakai, Tomoya Hirota, Yuri Aikawa, and Satoshi Yamamoto

Published
2016
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123. ABUNDANCE ANOMALY OF THE 13C ISOTOPIC SPECIES OF c-C3H2 IN THE LOW-MASS STAR FORMATION REGION L1527.

Author

Kento Yoshida, Nami Sakai, Tomoya Tokudome, Ana López-Sepulcre, Yoshimasa Watanabe, Shuro Takano, Bertrand Lefloch, Cecilia Ceccarelli, Rafael Bachiller, Emmanuel Caux, Charlotte Vastel, and Satoshi Yamamoto

Subjects
CYCLOPROPENYLIDENE, CARBON isotopes, CIRCUMSTELLAR matter, STELLAR evolution, ISOTOPE exchange reactions
Abstract

The rotational spectral lines of c-C3H2 and two kinds of the 13C isotopic species, c- ( symmetry) and c- (Cs symmetry), have been observed in the 1–3 mm band toward the low-mass star-forming region L1527. We have detected 7, 3, and 6 lines of c-C3H2, c-, and c-, respectively, with the Nobeyama 45 m telescope and 34, 6, and 13 lines, respectively, with the IRAM 30 m telescope, where seven, two, and two transitions, respectively, are observed with both telescopes. With these data, we have evaluated the column densities of the normal and 13C isotopic species. The [c-C3H2]/[c-] ratio is determined to be 310 ± 80, while the [c-C3H2]/[c-] ratio is determined to be 61 ± 11. The [c-C3H2]/[c-] and [c-C3H2]/[c-] ratios expected from the elemental 12C/13C ratio are 60–70 and 30–35, respectively, where the latter takes into account the statistical factor of 2 for the two equivalent carbon atoms in c-C3H2. Hence, this observation further confirms the dilution of the 13C species in carbon-chain molecules and their related molecules, which are thought to originate from the dilution of 13C+ in the gas-phase C+ due to the isotope exchange reaction: . Moreover, the abundances of the two 13C isotopic species are different from each other. The ratio of c- species relative to c- is determined to be 0.20 ± 0.05. If 13C were randomly substituted for the three carbon atoms, the [c-]/[c-] ratio would be 0.5. Hence, the observed ratio indicates that c- exists more favorably. Possible origins of the different abundances are discussed. [ABSTRACT FROM AUTHOR]

Published
2015
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124. Processus de fractionnement chimique du milieu interstellaire : l'apport des observations à haute résolution spatiale dans des environnements proto-stellaires complexes

Author

Evans, Lucy Elizabeth, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier - Toulouse III, Charlotte Vastel, and Francesco Fontani

Subjects
Fractionnement, Isotope, Isotopic, Astrochimie, Fractionation, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Protostellar core, Astrochemistry, Noyau protostellaire
Abstract

L'étude du fractionnement peut rassembler de manière unique des scientifiques de plusieurs domaines afin de répondre à de grandes questions. Comme nous le verrons, le domaine astrochimique du fractionnement peut être utilisé pour détecter les empreintes révélatrices de processus chimiques spécifiques qui se produisent tout au long du processus de formation des étoiles, depuis le nuage moléculaire froid jusquàu système solaire actuel. En reliant ces étapes entre elles, le fractionnement est essentiel pour d´evoiler les origines de la vie en découvrant l'histoire chimique d'importantes molécules vitales et de leurs précurseurs. Dans cette thèse, je présenterai les résultats de deux études axées sur la mesure des rapports de fractionnement de deux des éléments les plus abondants et les plus importants dans le processus de formation des étoiles : l'hydrogène (deutération) et l'azote. La recherche présentée ici d´etaille également mes contributions à deux collaborations du Grand Projet en utilisant les données interférométriques d'ALMA et de NOEMA. À cette fin, j'ai analysé les observations NOEMA de OMC-2 FIR4, censé représenter l'un des environnements de formation d'étoiles les plus proches de celui de notre jeune proto-Soleil. En utilisant des techniques de transfert radiatif, j'ai mesuré le fractionnement de l'azote de plusieurs espèces contenant de l'azote à une petite échelle sans précédent vers cette source, permettant la première comparaison entre des espèces qui sont censées présenter un comportement de fractionnement différent et, parallèlement, la recherche de preuves de mécanismes de fractionnement se produisant dans cette source. Les résultats ont montré que, comme on pourrait s'y attendre dans une telle source encastrée, le fractionnement ne se produit pas aux échelles sondées, malgré l'existence d'un gradient précédemment détecté dans le taux d'ionisation des rayons cosmiques, ce qui pourrait d´eclencher un fractionnement dû à une photodissociation sélective dans un cas moins encastré. Cette étude renforce donc l'image actuelle du fractionnement de l'azote et donne une idée de la chimie qui a pu se produire dans un jeune environnement proto-solaire (Evans et al. 2022). Pour l'étude ALMA, j'ai dirigé l'analyse des observations de H2CO vers le protobinaire [BHB2007] 11, obtenant la toute première mesure du rapport de deutération dans cette source. Mes résultats suggèrent que la nature dynamique de cette source affecte le mécanisme de deutération en jeu pour les molécules organiques représentant les précurseurs d'espèces complexes vitales pour la vie. En effet, les résultats obtenus renforcent les suggestions selon lesquelles l'effet de chauffage local résultant des interactions entre le matériau des courants entrants et le gaz local quiescent contribue à la sublimation des grains de poussière des composés organiques et de leurs isotopologues deutérés.; L'étude du fractionnement peut rassembler de manière unique des scientifiques de plusieurs domaines afin de répondre à de grandes questions. Comme nous le verrons, le domaine astrochimique du fractionnement peut être utilisé pour détecter les empreintes révélatrices de processus chimiques spécifiques qui se produisent tout au long du processus de formation des étoiles, depuis le nuage moléculaire froid jusquàu système solaire actuel. En reliant ces étapes entre elles, le fractionnement est essentiel pour d´evoiler les origines de la vie en découvrant l'histoire chimique d'importantes molécules vitales et de leurs précurseurs. Dans cette thèse, je présenterai les résultats de deux études axées sur la mesure des rapports de fractionnement de deux des éléments les plus abondants et les plus importants dans le processus de formation des étoiles : l'hydrogène (deutération) et l'azote. La recherche présentée ici d´etaille également mes contributions à deux collaborations du Grand Projet en utilisant les données interférométriques d'ALMA et de NOEMA. À cette fin, j'ai analysé les observations NOEMA de OMC-2 FIR4, censé représenter l'un des environnements de formation d'étoiles les plus proches de celui de notre jeune proto-Soleil. En utilisant des techniques de transfert radiatif, j'ai mesuré le fractionnement de l'azote de plusieurs espèces contenant de l'azote à une petite échelle sans précédent vers cette source, permettant la première comparaison entre des espèces qui sont censées présenter un comportement de fractionnement différent et, parallèlement, la recherche de preuves de mécanismes de fractionnement se produisant dans cette source. Les résultats ont montré que, comme on pourrait s'y attendre dans une telle source encastrée, le fractionnement ne se produit pas aux échelles sondées, malgré l'existence d'un gradient précédemment détecté dans le taux d'ionisation des rayons cosmiques, ce qui pourrait d´eclencher un fractionnement dû à une photodissociation sélective dans un cas moins encastré. Cette étude renforce donc l'image actuelle du fractionnement de l'azote et donne une idée de la chimie qui a pu se produire dans un jeune environnement proto-solaire (Evans et al. 2022). Pour l'étude ALMA, j'ai dirigé l'analyse des observations de H2CO vers le protobinaire [BHB2007] 11, obtenant la toute première mesure du rapport de deutération dans cette source. Mes résultats suggèrent que la nature dynamique de cette source affecte le mécanisme de deutération en jeu pour les molécules organiques représentant les précurseurs d'espèces complexes vitales pour la vie. En effet, les résultats obtenus renforcent les suggestions selon lesquelles l'effet de chauffage local résultant des interactions entre le matériau des courants entrants et le gaz local quiescent contribue à la sublimation des grains de poussière des composés organiques et de leurs isotopologues deutérés.

Published
2022

125. La deutération de l'eau dans les régions de formation stellaire : Apport des données spectroscopiques Herschel/HIFI

Author

Coutens, Audrey, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier - Toulouse III, and Charlotte VASTEL

Subjects
interstellar medium, proto-étoiles de faible masse, deuterated water, milieu interstellaire, observations hétérodynes, formation stellaire, astrochemistry, abundances, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], astrochimie, abondances, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], star formation, Herschel/HIFI, low-mass protostars, heterodyne observations, molécules: eau, eau deutérée, molecules: water
Abstract

Water (H2O) is one of the most abundant molecules in the interstellar medium. In addition to being a primordial ingredient in the emergence of life, this species plays an essential role in the process of star formation through the cooling of warm gas. It also controls the chemistry for many species, either in the gas phase or on the grain surfaces. Studying its deuterated form HDO is a unique opportunity, through the estimation of the HDO/H2O ratio, to constrain the mechanisms of water formation and to better understand the origin of water contained in terrestrial oceans. Indeed, recent results obtained with the Herschel satellite show that the HDO/H2O ratio observed in comets is similar to the value measured in oceans (~ 1.5 10-4), which suggests that comets could have brought a large fraction to Earth to form the oceans during heavy bombardments (Hartogh et al. 2011). In this thesis, I was interested in the study of deuterated water in the first stages of star formation, the Class 0 stage, which precede the formation of the protoplanetary disk leading to the birth of comets and planets. Through a 1D non-Local Thermodynamic Equilibrium radiative transfer modeling of the line profiles of the numerous HDO and H218O transitions detected with the HIFI (Heterodyne Instrument for Far-Infrared) instrument onboard the Herschel Space Observatory and ground-based telescopes (IRAM, JCMT), I determined that the HDO/H2O ratios of the solar-type protostar IRAS 16293-2422 was about 2% in the hot corino, the inner part of the protostellar envelope sufficiently warm (T > 100 K) to desorb in gas phase the water molecules trapped in the icy grain mantles, and about 0.5% in the colder part of the envelope. This study (Coutens et al. 2012) also allowed me to show that an absorbing layer rich in water surrounds the protostar. This layer could be produced by the photo-desorption through the UV field of the water molecules frozen on the grains, on the edges of the molecular cloud. The HDO/H2O ratios as well as the D2O/HDO ratios determined in IRAS 16293-2422 enable to constrain the conditions of water formation in this kind of objects and in particular suggest that water would be formed before the gravitational collapse of the cloud. This study was then extended to other solar-type protostars NGC1333 IRAS4A and NGC1333 IRAS4B, for which I estimated the abundances of deuterated water and noticed that an extended absorbing layer also surrounds these sources. The high HDO/H2O ratios determined in IRAS 16293-2422 suggest that mechanisms are required between the Class 0 stage and the comets formation to decrease these isotopic ratios. It is however necessary to study a larger sample of protostars to know if this trend is observed in most of the sources. The HDO abundances obtained in NGC1333 IRAS4A and NGC1333 IRAS4B will consequently be useful to estimate their HDO/H2O ratios. Finally, I also studied deuterated water in protostellar objects more massive and more luminous than solar-type protostars and show here the case of the ultra-compact HII region G34.26+0.15.; L'eau (H2O) est une des molécules les plus abondantes du milieu interstellaire. En plus d'être un ingrédient nécessaire à l'apparition de la Vie, elle joue également un rôle important dans le processus de formation stellaire à travers le refroidissement du gaz chaud et contrôle aussi la chimie de nombreuses autres espèces, que ce soit en phase gazeuse ou à la surface des grains. Étudier sa forme deutérée HDO constitue un moyen unique, à travers l'estimation du rapport HDO/H2O, de contraindre les mécanismes de formation de l'eau ainsi que de mieux comprendre l'origine de l'eau des océans terrestres. Les résultats récents obtenus avec le satellite Herschel montrent en effet que le rapport HDO/H2O observé dans les comètes est similaire à celui mesuré dans les océans (~ 1.5 10-4), suggérant que l'eau pourrait avoir été apportée sur Terre par les comètes lors de grands bombardements (Hartogh et al. 2011). Dans cette thèse, je me suis intéressée à l'étude de l'eau deutérée durant les premières étapes de la formation stellaire, la phase de Classe 0, qui précèdent la formation du disque proto-planétaire menant à la naissance des planètes et des comètes. En modélisant avec un code 1D de transfert radiatif hors-Equilibre Thermodynamique Local les profils des nombreuses raies de HDO et H218O observées avec l'instrument HIFI (Heterodyne Instrument for Far-Infrared) de l'Observatoire Spatial Herschel et des télescopes terrestres (IRAM, JCMT), j'ai déterminé des rapports HDO/H2O de la proto-étoile de type solaire IRAS 16293-2422 de l'ordre de 2% dans le hot corino, la partie interne de l'enveloppe suffisamment chaude (T>100 K) pour que les molécules d'eau collées à la surface des grains désorbent en phase gazeuse, et de 0.5% dans l'enveloppe externe plus froide. Grâce à ce travail (Coutens et al. 2012), la présence en avant-plan d'une couche d'absorption riche en eau a été mise en évidence observationnellement pour la première fois. Elle pourrait être due à des processus de photo-désorption des molécules d'eau piégées dans les manteaux de glace des grains, en bordure de nuage moléculaire, par le champ interstellaire UV. Les estimations des rapports HDO/H2O ainsi que D2O/HDO dans cette source permettent de contraindre les conditions de formation de l'eau dans ce type d'objet et suggèrent notamment que l'eau se serait probablement formée avant l'effondrement gravitationnel du nuage. Cette étude a ensuite été étendue à d'autres proto-étoiles de type solaire NGC 333 IRAS4A et NGC1333 IRAS4B pour lesquelles j'ai estimé les abondances d'eau deutérée et constaté qu'une couche d'absorption étendue entourait également ces sources. Les rapports HDO/H2O élevés de la proto-étoile IRAS 16293-2422 suggèrent que des mécanismes nécessaires à la diminution de ces rapports isotopiques prennent place entre l'étape de Classe 0 et la formation des comètes. Il faudra néanmoins étudier un plus grand échantillon de proto-étoiles pour savoir si cette tendance est générale ou non. Les abondances de HDO obtenues dans les proto-étoiles NGC1333 IRAS4A et NGC1333 IRAS4B serviront donc à de prochaines estimations des rapports HDO/H2O. Enfin, je me suis également attachée à étudier l'eau deutérée dans des sources proto-stellaires beaucoup plus massives et plus lumineuses que les proto-étoiles de type solaire et présente ici le cas de la région HII ultra-compacte G34.26+0.15.

Published
2012

126. Water deuteration in star-forming regions : Contribution of Herschel/HIFI spectroscopic data

Author

Coutens, Audrey, Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier - Toulouse III, and Charlotte VASTEL

Subjects
interstellar medium, proto-étoiles de faible masse, deuterated water, milieu interstellaire, observations hétérodynes, formation stellaire, astrochemistry, abundances, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], astrochimie, abondances, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], star formation, Herschel/HIFI, low-mass protostars, heterodyne observations, molécules: eau, eau deutérée, molecules: water
Abstract

Water (H2O) is one of the most abundant molecules in the interstellar medium. In addition to being a primordial ingredient in the emergence of life, this species plays an essential role in the process of star formation through the cooling of warm gas. It also controls the chemistry for many species, either in the gas phase or on the grain surfaces. Studying its deuterated form HDO is a unique opportunity, through the estimation of the HDO/H2O ratio, to constrain the mechanisms of water formation and to better understand the origin of water contained in terrestrial oceans. Indeed, recent results obtained with the Herschel satellite show that the HDO/H2O ratio observed in comets is similar to the value measured in oceans (~ 1.5 10-4), which suggests that comets could have brought a large fraction to Earth to form the oceans during heavy bombardments (Hartogh et al. 2011). In this thesis, I was interested in the study of deuterated water in the first stages of star formation, the Class 0 stage, which precede the formation of the protoplanetary disk leading to the birth of comets and planets. Through a 1D non-Local Thermodynamic Equilibrium radiative transfer modeling of the line profiles of the numerous HDO and H218O transitions detected with the HIFI (Heterodyne Instrument for Far-Infrared) instrument onboard the Herschel Space Observatory and ground-based telescopes (IRAM, JCMT), I determined that the HDO/H2O ratios of the solar-type protostar IRAS 16293-2422 was about 2% in the hot corino, the inner part of the protostellar envelope sufficiently warm (T > 100 K) to desorb in gas phase the water molecules trapped in the icy grain mantles, and about 0.5% in the colder part of the envelope. This study (Coutens et al. 2012) also allowed me to show that an absorbing layer rich in water surrounds the protostar. This layer could be produced by the photo-desorption through the UV field of the water molecules frozen on the grains, on the edges of the molecular cloud. The HDO/H2O ratios as well as the D2O/HDO ratios determined in IRAS 16293-2422 enable to constrain the conditions of water formation in this kind of objects and in particular suggest that water would be formed before the gravitational collapse of the cloud. This study was then extended to other solar-type protostars NGC1333 IRAS4A and NGC1333 IRAS4B, for which I estimated the abundances of deuterated water and noticed that an extended absorbing layer also surrounds these sources. The high HDO/H2O ratios determined in IRAS 16293-2422 suggest that mechanisms are required between the Class 0 stage and the comets formation to decrease these isotopic ratios. It is however necessary to study a larger sample of protostars to know if this trend is observed in most of the sources. The HDO abundances obtained in NGC1333 IRAS4A and NGC1333 IRAS4B will consequently be useful to estimate their HDO/H2O ratios. Finally, I also studied deuterated water in protostellar objects more massive and more luminous than solar-type protostars and show here the case of the ultra-compact HII region G34.26+0.15.; L'eau (H2O) est une des molécules les plus abondantes du milieu interstellaire. En plus d'être un ingrédient nécessaire à l'apparition de la Vie, elle joue également un rôle important dans le processus de formation stellaire à travers le refroidissement du gaz chaud et contrôle aussi la chimie de nombreuses autres espèces, que ce soit en phase gazeuse ou à la surface des grains. Étudier sa forme deutérée HDO constitue un moyen unique, à travers l'estimation du rapport HDO/H2O, de contraindre les mécanismes de formation de l'eau ainsi que de mieux comprendre l'origine de l'eau des océans terrestres. Les résultats récents obtenus avec le satellite Herschel montrent en effet que le rapport HDO/H2O observé dans les comètes est similaire à celui mesuré dans les océans (~ 1.5 10-4), suggérant que l'eau pourrait avoir été apportée sur Terre par les comètes lors de grands bombardements (Hartogh et al. 2011). Dans cette thèse, je me suis intéressée à l'étude de l'eau deutérée durant les premières étapes de la formation stellaire, la phase de Classe 0, qui précèdent la formation du disque proto-planétaire menant à la naissance des planètes et des comètes. En modélisant avec un code 1D de transfert radiatif hors-Equilibre Thermodynamique Local les profils des nombreuses raies de HDO et H218O observées avec l'instrument HIFI (Heterodyne Instrument for Far-Infrared) de l'Observatoire Spatial Herschel et des télescopes terrestres (IRAM, JCMT), j'ai déterminé des rapports HDO/H2O de la proto-étoile de type solaire IRAS 16293-2422 de l'ordre de 2% dans le hot corino, la partie interne de l'enveloppe suffisamment chaude (T>100 K) pour que les molécules d'eau collées à la surface des grains désorbent en phase gazeuse, et de 0.5% dans l'enveloppe externe plus froide. Grâce à ce travail (Coutens et al. 2012), la présence en avant-plan d'une couche d'absorption riche en eau a été mise en évidence observationnellement pour la première fois. Elle pourrait être due à des processus de photo-désorption des molécules d'eau piégées dans les manteaux de glace des grains, en bordure de nuage moléculaire, par le champ interstellaire UV. Les estimations des rapports HDO/H2O ainsi que D2O/HDO dans cette source permettent de contraindre les conditions de formation de l'eau dans ce type d'objet et suggèrent notamment que l'eau se serait probablement formée avant l'effondrement gravitationnel du nuage. Cette étude a ensuite été étendue à d'autres proto-étoiles de type solaire NGC 333 IRAS4A et NGC1333 IRAS4B pour lesquelles j'ai estimé les abondances d'eau deutérée et constaté qu'une couche d'absorption étendue entourait également ces sources. Les rapports HDO/H2O élevés de la proto-étoile IRAS 16293-2422 suggèrent que des mécanismes nécessaires à la diminution de ces rapports isotopiques prennent place entre l'étape de Classe 0 et la formation des comètes. Il faudra néanmoins étudier un plus grand échantillon de proto-étoiles pour savoir si cette tendance est générale ou non. Les abondances de HDO obtenues dans les proto-étoiles NGC1333 IRAS4A et NGC1333 IRAS4B serviront donc à de prochaines estimations des rapports HDO/H2O. Enfin, je me suis également attachée à étudier l'eau deutérée dans des sources proto-stellaires beaucoup plus massives et plus lumineuses que les proto-étoiles de type solaire et présente ici le cas de la région HII ultra-compacte G34.26+0.15.

Published
2012

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