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1. Orion A’s complete 3D magnetic field morphology

Author

M. Tahani, J. Glover, W. Lupypciw, J. L. West, R. Kothes, R. Plume, S. Inutsuka, M.-Y. Lee, I. A. Grenier, L. B. G. Knee, J. C. Brown, Y. Doi, T. Robishaw, M. Haverkorn, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
stars: formation, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, magnetic fields, ISM: clouds, Astrophysics - Astrophysics of Galaxies, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), ISM: magnetic fields, Astrophysics::Galaxy Astrophysics
Abstract

Magnetic fields permeate the interstellar medium and are important in the star formation process. Determining the 3D magnetic fields of molecular clouds will allow us to better understand their role in the evolution of these clouds and formation of stars. We fully reconstruct the approximate three-dimensional (3D) magnetic field morphology of the Orion A molecular cloud (on scales of a few to ~100 pc) using Galactic magnetic field models, as well as present line-of-sight and plane-of-sky magnetic field observations. While previous studies identified the 3D magnetic field morphology of the Orion A cloud as an arc shape, in this study we provide the orientation of this arc-shaped field and its plane-of-sky direction, for the first time. We find that this 3D field is a tilted, semi-convex (from our point of view) structure and mostly points in the direction of decreasing latitude and longitude on the plane of the sky, from our vantage point. The previously identified bubbles and events in this region were key in shaping this arc-shaped magnetic field morphology., Comment: 9 pages, 9 Figures, accepted in Astronomy & Astrophysics

Published
2022
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2. 3D magnetic-field morphology of the Perseus molecular cloud

Author

M. Tahani, W. Lupypciw, J. Glover, R. Plume, J. L. West, R. Kothes, S. Inutsuka, M.-Y. Lee, T. Robishaw, L. B. G. Knee, J. C. Brown, Y. Doi, I. A. Grenier, M. Haverkorn, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
stars: formation, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, magnetic fields, ISM: clouds, Astrophysics - Astrophysics of Galaxies, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), evolution, ISM: magnetic fields, Astrophysics::Galaxy Astrophysics, ISM: general
Abstract

Despite recent observational and theoretical advances in mapping the magnetic fields associated with molecular clouds, their three-dimensional (3D) morphology remains unresolved. Multi-wavelength and multi-scale observations will allow us to paint a comprehensive picture of the magnetic fields of these star-forming regions. We reconstruct the 3D magnetic field morphology associated with the Perseus molecular cloud and compare it with predictions of cloud-formation models. These cloud-formation models predict a bending of magnetic fields associated with filamentary molecular clouds. We compare the orientation and direction of this field bending with our 3D magnetic field view of the Perseus cloud. We use previous line-of-sight and plane-of-sky magnetic field observations, as well as Galactic magnetic field models, to reconstruct the complete 3D magnetic field vectors and morphology associated with the Perseus cloud. We approximate the 3D magnetic field morphology of the cloud as a concave arc that points in the decreasing longitude direction in the plane of the sky (from our point of view). This field morphology preserves a memory of the Galactic magnetic field. In order to compare this morphology to cloud-formation model predictions, we assume that the cloud retains a memory of its most recent interaction. Incorporating velocity observations, we find that the line-of-sight magnetic field observations are consistent with predictions of shock-cloud-interaction models. To our knowledge, this is the first time that the 3D magnetic fields of a molecular cloud have been reconstructed. We find the 3D magnetic field morphology of the Perseus cloud to be consistent with the predictions of the shock-cloud-interaction model, which describes the formation mechanism of filamentary molecular clouds., 13 pages,12 figures, accepted for publication in Astronomy & Astrophysics. updated to correct an affiliation

Published
2022
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4. CHIMPS: Physical properties of molecular clumps across the inner Galaxy

Author

Toby J. T. Moore, R. Plume, Mark Thompson, Sarah Ragan, James Urquhart, Andrew Rigby, Geumsook Park, Nicolas Peretto, Malcolm J. Currie, and David Eden

Subjects
Milky Way, Population, FOS: Physical sciences, Astrophysics, Excitation temperature, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Virial theorem, 0103 physical sciences, education, 010303 astronomy & astrophysics, QC, Astrophysics::Galaxy Astrophysics, QB, Physics, education.field_of_study, Spiral galaxy, 010308 nuclear & particles physics, Molecular cloud, Astronomy and Astrophysics, Galactic plane, Astrophysics - Astrophysics of Galaxies, Galaxy, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA)
Abstract

The latest generation of high-angular-resolution unbiased Galactic plane surveys in molecular-gas tracers are enabling the interiors of molecular clouds to be studied across a range of environments. The CHIMPS survey simultaneously mapped a sector of the inner Galactic plane, within 27.8 < l < 46.2 deg and |b| < 0.5 deg, in 13CO and C18O (3-2) at 15 arcsec resolution. The combination of CHIMPS data with 12CO (3-2) data from the COHRS survey has enabled us to perform a voxel-by-voxel local-thermodynamic-equilibrium analysis, determining the excitation temperature, optical depth, and column density of 13CO at each l,b,v position. Distances to discrete sources identified by FellWalker in the 13CO (3-2) emission maps were determined, allowing the calculation of numerous physical properties of the sources, and we present the first source catalogues in this paper. We find that, in terms of size and density, the CHIMPS sources represent an intermediate population between large-scale molecular clouds identified by CO and dense clumps seen in dust emission, and therefore represent the bulk transition from the diffuse to the dense phase of molecular gas. We do not find any significant systematic variations in the masses, column densities, virial parameters, excitation temperature, or the turbulent pressure over the range of Galactocentric distance probed, but we do find a shallow increase in the mean volume density with increasing Galactocentric distance. We find that inter-arm clumps have significantly narrower linewidths, and lower virial parameters and excitation temperatures than clumps located in spiral arms. When considering the most reliable distance-limited subsamples, the largest variations occur on the clump-to-clump scale, echoing similar recent studies that suggest that the star-forming process is largely insensitive to the Galactic-scale environment, at least within the inner disc., abridged. 25 pages, 14 figures, 7 tables. Accepted for publication in Astronomy & Astrophysics. v2: typos corrected & improved layout

Published
2019
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6. An analysis of star formation with Herschel in the Hi-GAL Survey. II. The tips of the Galactic bar

Author

Norikazu Mizuno, B. Maiolo, Sergio Molinari, D. Russeil, F. Piacentini, A. Di Giorgio, Stefano Pezzuto, Y. Maruccia, Francesco Strafella, Davide Elia, Joseph C. Mottram, M. R. Pestalozzi, R. Plume, E. Schisano, Alberto Noriega-Crespo, Toshikazu Onishi, Sean Carey, Yasuo Fukui, Akira Mizuno, Deborah Paradis, Toby J. T. Moore, Roberta Paladini, M. Veneziani, 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), Laboratoire d'Astrophysique de Marseille (LAM), 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), Veneziani, M., Schisano, E., Elia, D., Noriega Crespo, A., Carey, S., Di Giorgio, A., Fukui, Y., Maiolo, B. M. T., Maruccia, Ylenia, Mizuno, A., Mizuno, N., Molinari, S., Mottram, J. C., Moore, T. J. T., Onishi, T., Paladini, R., Paradis, D., Pestalozzi, M., Pezzuto, S., Piacentini, F., Plume, R., Russeil, D., and Strafella, Francesco

Subjects
Infrared, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, surveys, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, stars formation, Galaxy stellar content, infrared ISM, surveys, Galaxy: stellar content, Infrared: ISM, Stars: formation, Surveys, Astronomy and Astrophysics, Space and Planetary Science, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, infrared: ISM, Spiral galaxy, stars: formation, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Star formation, Galactic Center, Galactic plane, Astrophysics - Astrophysics of Galaxies, Stars, Star cluster, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), Longitude
Abstract

We present the physical and evolutionary properties of prestellar and protostellar clumps in the Herschel Infrared GALactic plane survey (Hi-GAL) in two large areas centered in the Galactic plane and covering the tips of the long Galactic bar at the intersection with the spiral arms. The areas fall in the longitude ranges 19 < l < 33 and 340 < l < 350, while latitude is -1 < b < 1. Newly formed high mass stars and prestellar objects are identified and their properties derived and compared. A study is also presented on five giant molecular complexes at the further edge of the bar. The star-formation rate was estimated from the quantity of proto-stars expected to form during the collapse of massive turbulent clumps into star clusters. This new method was developed by applying a Monte Carlo procedure to an evolutionary model of turbulent cores and takes into account the wide multiplicity of sources produced during the collapse. The star-formation rate density values at the tips are 1.2 +- 0.3 10-3 Msol/yr/kpc2 and 1.5+-0.3 10-3 Msol/yr/kpc2 in the first and fourth quadrant, respectively. The same values estimated on the entire field of view, that is including the tips of the bar and background and foreground regions, are 0.9+-0.2 10-3 Msol/yr/kpc2 and 0.8+-0.2 10-3 Msol/yr/kpc2. The conversion efficiency is approximately 0.8% in the first quadrant and 0.5% in the fourth quadrant, and does not show a significant difference in proximity of the bar. The star forming regions identified through CO contours at the further edge of the bar show star-formation rate densities larger than the surrounding regions but their conversion efficiencies are comparable. Our results suggest that the star-formation activity at the bar is due to a large amount of dust and molecular material rather than being due to a triggering process., 16 pages, 17 figures, accepted for publication in A&A

Published
2017
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8. Physical and chemical differentiation of the luminous star-forming region W49A. Results from the JCMT Spectral Legacy Survey

Author

R. Plume, Z. Nagy, F. F. S. van der Tak, Gary A. Fuller, and Kapteyn Astronomical Institute

Subjects
Physics, stars: formation, Field (physics), Spatial structure, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Star (graph theory), Astrophysics - Astrophysics of Galaxies, Galaxy, ISM: molecules, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Spatial ecology, Spectral resolution, Chemical composition, Excitation
Abstract

The massive and luminous star-forming region W49A is a well known Galactic candidate to probe the physical conditions and chemistry similar to those expected in external starburst galaxies. We aim to probe the physical and chemical structure of W49A on a spatial scale of ~0.8 pc based on the JCMT Spectral Legacy Survey, which covers the frequency range between 330 and 373 GHz. The wide 2x2 arcminutes field and the high spectral resolution of the HARP instrument on JCMT provides information on the spatial structure and kinematics of the cloud. For species where multiple transitions are available, we estimate excitation temperatures and column densities. We detected 255 transitions corresponding to 60 species in the 330-373 GHz range at the center position of W49A. Excitation conditions can be probed for 16 molecules. The chemical composition suggests the importance of shock-, PDR-, and hot core chemistry. Many molecular lines show a significant spatial extent across the maps including high density tracers (e.g. HCN, HNC, CS, HCO+) and tracers of UV-irradiation (e.g. CN and C2H). Large variations are seen between the sub-regions with mostly blue-shifted emission toward the Eastern tail, mostly red-shifted emission toward the Northern clump, and emission peaking around the expected source velocity toward the South-west clump. A comparison of column density ratios of characteristic species observed toward W49A to Galactic PDRs suggests that while the chemistry toward the W49A center is driven by a combination of UV-irradiation and shocks, UV-irradiation dominates for the Northern Clump, Eastern tail, and South-west clump regions. A comparison to a starburst galaxy and an AGN suggests similar C2H, CN, and H2CO abundances (with respect to the dense gas tracer 34CS) between the ~0.8 pc scale probed for W49A and the >1 kpc regions in external galaxies with global star-formation., Proposed for acceptance in A&A, abstract abridged

Published
2015

9. THOR: The H i, OH, Recombination line survey of the Milky Way

Author

S. Bihr, H. Beuther, J. Ott, K. G. Johnston, A. Brunthaler, L. D. Anderson, F. Bigiel, P. Carlhoff, E. Churchwell, S. C. O. Glover, P. F. Goldsmith, F. Heitsch, T. Henning, M. H. Heyer, T. Hill, A. Hughes, R. S. Klessen, H. Linz, S. N. Longmore, N. M. McClure-Griffiths, K. M. Menten, F. Motte, Q. Nguyen-Luong, R. Plume, S. E. Ragan, N. Roy, P. Schilke, N. Schneider, R. J. Smith, J. M. Stil, and J. S.

Published
2015
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10. A non-equilibrium ortho-to-para ratio of water in the Orion PDR

Author

R. Plume, Yun-Young Choi, Edwin Bergin, F. F. S. van der Tak, and Kapteyn Astronomical Institute

Subjects
Physics, ISM: individual objects: Orion Bar, Interstellar cloud, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, ISM: molecules, Gas phase, ISM: individual objects: Orion S, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Formation water, Bar (unit)
Abstract

Context. The ortho-to-para ratio (OPR) of H2O is thought to be sensitive to the temperature of water formation. The OPR of H2O is thus useful for studying the formation mechanism of water. Aims: We investigate the OPR of water in the Orion PDR (photon-dominated region), at the Orion Bar and Orion S positions, using data from Herschel/HIFI. Methods: We detect the ground-state lines of ortho- and para-H218O in the Orion Bar and Orion S and estimate the column densities using local thermodynamical equilibrium (LTE) and non-LTE methods. Results: Based on our calculations, the OPR in the Orion Bar is 0.1-0.5, which is unexpectedly low given the gas temperature of ~85 K, and also lower than the values measured for other interstellar clouds and protoplanetary disks. Toward Orion S, our OPR estimate is below 2. Conclusions: This low OPR at 2 positions in the Orion PDR is inconsistent with gas phase formation and with thermal evaporation from dust grains, but it may be explained by photodesorption. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendices are available in electronic form at http://www.aanda.org

Published
2014
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11. Triggered/sequential star formation? A multi-phase ISM study around the prominent IRDC G18.93-0.03

Author

Frederic Schuller, Anika Schmiedeke, Thomas Henning, Jeroen M. Stil, Henrik Beuther, Malcolm Walmsley, J. Tackenberg, and R. Plume

Subjects
Physics, 010308 nuclear & particles physics, Star formation, Young stellar object, FOS: Physical sciences, Astronomy and Astrophysics, Virial mass, Astrophysics, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Virial theorem, Protein filament, Wavelength, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Ionization, 0103 physical sciences, Infrared dark cloud, 010303 astronomy & astrophysics
Abstract

G18.93-0.03 is a prominent dust complex within an 0.8deg long filament, with the molecular clump G18.93/m being IR dark from near IR wavelength up to 160mu. Spitzer composite images show an IR bubble spatially associated with G18.93. We use GRS 13CO and IRAM 30m H13CO+ data to disentangle the spatial structure of the region. From ATLASGAL submm data we calculate the gas mass, while we use the H13CO+ line width to estimate its virial mass. Using HERSCHEL data we produce temperature maps from fitting the SED. With the MAGPIS 20cm and SuperCOSMOS Halpha data we trace the ionized gas, and the VGPS HI survey provides information on the atomic hydrogen gas. We show that the bubble is spatially associated with G18.93, located at a kinematic near distance of 3.6kpc. With 280Msun, the most massive clump within G18.93 is G18.93/m. The virial analysis shows that it may be gravitationally bound and has neither Spitzer young stellar objects nor mid-IR point sources within. Fitting the SED reveals a temperature distribution that decreases towards its center, but heating from the ionizing source puts it above the general ISM temperature. We find that the bubble is filled by HII gas, ionized by an O8.5 star. Between the ionizing source and the IR dark clump G18.93/m we find a layered structure, from ionized to atomic to molecular hydrogen, revealing a PDR. Furthermore, we identify an additional velocity component within the bubble's 8mu emission rim at the edge of the infrared dark cloud and speculate that it might be shock induced by the expanding HII region. While the elevated temperature allows for the build-up of larger fragments, and the shock induced velocity component may lead to additional turbulent support, we do not find conclusive evidence that the massive clump G18.93/m is prone to collapse because of the expanding HII region., Accepted for publication in A&A

Published
2012

12. Herschel/HIFI discovery of interstellar chloronium (H2Cl+)

Author

D. C. Lis, J. C. Pearson, D. A. Neufeld, P. Schilke, H. S. P. Müller, H. Gupta, T. A. Bell, C. Comito, T. G. Phillips, E. A. Bergin, C. Ceccarelli, P. F. Goldsmith, G. A. Blake, A. Bacmann, A. Baudry, M. Benedettini, A. Benz, J. Black, A. Boogert, S. Bottinelli, S. Cabrit, P. Caselli, A. Castets, E. Caux, J. Cernicharo, C. Codella, A. Coutens, N. Crimier, N. R. Crockett, F. Daniel, K. Demyk, C. Dominic, M.-L. Dubernet, M. Emprechtinger, P. Encrenaz, E. Falgarone, A. Fuente, M. Gerin, T. F. Giesen, J. R. Goicoechea, F. Helmich, P. Hennebelle, Th. Henning, E. Herbst, P. Hily-Blant, Å. Hjalmarson, D. Hollenbach, T. Jack, C. Joblin, D. Johnstone, C. Kahane, M. Kama, M. Kaufman, A. Klotz, W. D. Langer, B. Larsson, J. Le Bourlot, B. Lefloch, F. Le Petit, D. Li, R. Liseau, S. D. Lord, A. Lorenzani, S. Maret, P. G. Martin, G. J. Melnick, K. M. Menten, P. Morris, J. A. Murphy, Z. Nagy, B. Nisini, V. Ossenkopf, S. Pacheco, L. Pagani, B. Parise, M. Pérault, R. Plume, S.-L. Qin, E. Roueff, M. Salez, A. Sandqvist, P. Saraceno, S. Schlemmer, K. Schuster, R. Snell, J. Stutzki, A. Tielens, N. Trappe, F. F. S. van der Tak, M. H. D. van der Wiel, E. van Dishoeck, C. Vastel, S. Viti, V. Wakelam, A. Walters, S. Wang, F. Wyrowski, H. W. Yorke, S. Yu, J. Zmuidzinas, Y. Delorme, J.-P. Desbat, R. Güsten, J.-M. Krieg, B. Delforge, California Institute of Technology (CALTECH), foreign laboratories (FL), CERN [Genève], I. Physikalisches Institut [Köln], Universität zu Köln = University of Cologne, Max Planck Institute for Radio Astronomy, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Astronomy [Ann Arbor], University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, 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 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), FORMATION STELLAIRE 2010, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), 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)-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 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (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 de Bordeaux (UB), Indiana University Cyclotron Facility (IUCF), Indiana University [Bloomington], Indiana University System-Indiana University System, 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), 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), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), CNRS INSU, UMR 5187, F-31028 Toulouse 4, France, UMR 5187 Toulouse, Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Université Paris sciences et lettres (PSL), Cahill Center for Astronomy and Astrophysics, 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 Univ, Dept Phys, Columbus, OH 43210 USA, Ohio State University [Columbus] (OSU), Ohio State Univ, Dept Astron & Chem, Columbus, OH 43210 USA, Onsala Space Observatory, Chalmers University of Technology [Göteborg], Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7 Canada, Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, 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), Science et Ingénierie des Matériaux et Procédés (SIMaP), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Modélisation Multi-échelles des Combustibles (LM2C), Service d'Etudes de Simulation du Comportement du combustibles (SESC), Département d'Etudes des Combustibles (DEC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Département d'Etudes des Combustibles (DEC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, Max-Planck-Institut für Radioastronomie (MPIFR), Infrared Processing and Analysis Center (IPAC), Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Roma (OAR), 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), SRON Netherlands Institute for Space Research (SRON), Department of Physics and Astronomy [Calgary], University of Calgary, Stockholm Observatory Department of Astronomy, Stockholm University, Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Laboratoire de Didactique André Revuz (LDAR (EA_4434)), Université d'Artois (UA)-Université Paris Diderot - Paris 7 (UPD7)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Leiden Observatory [Leiden], Universiteit Leiden, AMOR 2010, Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany, Univ Cologne, Inst Phys 1, 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-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)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), 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), Univ Toulouse UPS, Ctr Etud Spatiale Rayonnements, F-31062 Toulouse 9, France, Centre Etud Spatiale Rayonnements Toulouse, Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid 28850, Spain, Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid, École normale supérieure - Paris (ENS Paris), 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), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction de l'Energie Nucléaire (CEA-DEN), Harvard University [Cambridge]-Smithsonian Institution, CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA, CALTECH, Ctr Infrared Proc & Anal, Pasadena, Osservatorio di Astrofisica di Roma (OAR), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), Consiglio Nazionale delle Ricerche (CNR), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université Paris Diderot - Paris 7 (UPD7)-Université d'Artois (UA), Universiteit Leiden [Leiden], Astronomy, Kapteyn Astronomical Institute, 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, 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), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Chimie du CNRS (INC)-Institut National Polytechnique de Grenoble (INPG), Smithsonian Institution-Harvard University [Cambridge], Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-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)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Faure, Alexandre, Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Experimental Physics, STAR-FORMING REGION, CHLORINE-BEARING MOLECULES, FOS: Physical sciences, Astrophysics, 01 natural sciences, COLOGNE DATABASE, ISM: abundances, 0103 physical sciences, Absorption (logic), HYDROGEN-CHLORIDE, 010306 general physics, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, NGC 6334 I, Physics, SPECTROSCOPY, astrochemistry, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Space observatory, ISM: molecules, SPIRAL ARM CLOUDS, Interstellar medium, submillimetre: ISM, molecular processes, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), GROUND-STATE, ISOTOPIC RATIO, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], SUBMILLIMETER, line: identification
Abstract

We report the first detection of chloronium, H$_2$Cl$^+$, in the interstellar medium, using the HIFI instrument aboard the \emph{Herschel} Space Observatory. The $2_{12}-1_{01}$ lines of ortho-H$_2^{35}$Cl$^+$ and ortho-H$_2^{37}$Cl$^+$ are detected in absorption towards NGC~6334I, and the $1_{11}-0_{00}$ transition of para-H$_2^{35}$Cl$^+$ is detected in absorption towards NGC~6334I and Sgr~B2(S). The H$_2$Cl$^+$ column densities are compared to those of the chemically-related species HCl. The derived HCl/H$_2$Cl$^+$ column density ratios, $\sim$1--10, are within the range predicted by models of diffuse and dense Photon Dominated Regions (PDRs). However, the observed H$_2$Cl$^+$ column densities, in excess of $10^{13}$~cm$^{-2}$, are significantly higher than the model predictions. Our observations demonstrate the outstanding spectroscopic capabilities of HIFI for detecting new interstellar molecules and providing key constraints for astrochemical models., Comment: Accepted for publication in A&A, HIFI Special Issue; 4 pages, 2 figures, 1 table

Published
2010
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13. Herschel/HIFI detections of hydrides towards AFGL 2591. Envelope emission versus tenuous cloud absorption [Letter]

Author

Javier R. Goicoechea, M. Tafalla, Pierre Encrenaz, P. Stäuber, Jes K. Jørgensen, Jonathan Braine, T. Giannini, Laurent Pagani, Steven D. Doty, Alain Baudry, Michael Olberg, Rafael Bachiller, M. Marseille, Th. de Graauw, E. F. van Dishoeck, Lars E. Kristensen, R. Schieder, José Cernicharo, André Csillaghy, S. Bruderer, S. F. Wampfler, T. A. van Kempen, Paolo Saraceno, Arnold O. Benz, Gary J. Melnick, David A. Neufeld, T. Jacq, C. Dedes, J. Santiago-Garcia, N. Honingh, John C. Pearson, R. Shipman, Frank Helmich, D. Teyssier, M. Fich, A. Di Giorgio, Willem Jellema, Edwin Bergin, Per Bjerkeli, N. Whyborn, Paola Caselli, R. Plume, Ruud Visser, Dariusz C. Lis, M. Melchior, Fabrice Herpin, Christophe Risacher, B. Larsson, Emmanuel Caux, Brunella Nisini, C. McCoey, Christian Monstein, F. Daniel, Geoffrey A. Blake, Doug Johnstone, Gregory J. Herczeg, Umut A. Yildiz, Berengere Parise, Claudio Codella, Sylvain Bontemps, René Liseau, Milena Benedettini, Michiel R. Hogerheijde, Friedrich Wyrowski, Carsten Dominik, F. F. S. van der Tak, W. Bächtold, Asunción Fuente, 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), 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), Herschel Science Center [Madrid], European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), 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), 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 (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), 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), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), SRON Netherlands Institute for Space Research (SRON), INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Radioastronomie (MPIFR), École normale supérieure - Paris (ENS Paris), European Space Agency (ESA)-European Space Agency (ESA), 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-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, and Consiglio Nazionale delle Ricerche (CNR)

Subjects
Photon, FOS: Physical sciences, Astrophysics, 7. Clean energy, Far infrared, CHEMISTRY, EXCITATION, OUTFLOW, Solar and Stellar Astrophysics, Spectral resolution, H2O+, Absorption (electromagnetic radiation), Solar and Stellar Astrophysics (astro-ph.SR), Envelope (waves), QB, STAR-FORMING REGIONS, Physics, stars: formation, SPECTROSCOPY, INTERSTELLAR-MEDIUM, astrochemistry, [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], Diatomic molecule, ISM: molecules, Astrophysics - Solar and Stellar Astrophysics, GL-2591, 13. Climate action, Space and Planetary Science, ABUNDANCE, Outflow, ISM: individual objects: AFGL 2591, Excitation
Abstract

The Heterodyne Instrument for the Far Infrared (HIFI) onboard the Herschel Space Observatory allows the first observations of light diatomic molecules at high spectral resolution and in multiple transitions. Here, we report deep integrations using HIFI in different lines of hydrides towards the high-mass star forming region AFGL 2591. Detected are CH, CH+, NH, OH+, H2O+, while NH+ and SH+ have not been detected. All molecules except for CH and CH+ are seen in absorption with low excitation temperatures and at velocities different from the systemic velocity of the protostellar envelope. Surprisingly, the CH(JF,P = 3/2_2,- - 1/2_1,+) and CH+(J = 1 - 0, J = 2 - 1) lines are detected in emission at the systemic velocity. We can assign the absorption features to a foreground cloud and an outflow lobe, while the CH and CH+ emission stems from the envelope. The observed abundance and excitation of CH and CH+ can be explained in the scenario of FUV irradiated outflow walls, where a cavity etched out by the outflow allows protostellar FUV photons to irradiate and heat the envelope at larger distances driving the chemical reactions that produce these molecules., Comment: Accepted for publication in Astronomy and Astrophysics (HIFI first results issue)

Published
2010
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14. Herschel/HIFI spectroscopy of the intermediate mass protostar NGC7129 FIRS 2 [Letter]

Author

D. Johnstone, M. Fich, C. McCoey, T. A. van Kempen, A. Fuente, L. E. Kristensen, J. Cernicharo, P. Caselli, R. Visser, R. Plume, G. J. Herczeg, E. F. van Dishoeck, S. Wampfler, R. Bachiller, A. Baudry, M. Benedettini, E. Bergin, A. O. Benz, P. Bjerkeli, G. Blake, S. Bontemps, J. Braine, S. Bruderer, C. Codella, F. Daniel, A. M. di Giorgio, C. Dominik, S. D. Doty, P. Encrenaz, T. Giannini, J. R. Goicoechea, Th. de Graauw, F. Helmich, F. Herpin, M. R. Hogerheijde, T. Jacq, J. K. Jørgensen, B. Larsson, D. Lis, R. Liseau, M. Marseille, G. Melnick, D. Neufeld, B. Nisini, M. Olberg, B. Parise, J. Pearson, C. Risacher, J. Santiago-García, P. Saraceno, R. Shipman, M. Tafalla, F. van der Tak, F. Wyrowski, U. A. Yıldız, E. Caux, N. Honingh, W. Jellema, R. Schieder, D. Teyssier, N. Whyborn, 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), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), 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 (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), 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), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), 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), SRON Netherlands Institute for Space Research (SRON), INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], 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), ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Radioastronomie (MPIFR), Herschel Science Center [Madrid], European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Astronomy, 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, École normale supérieure - Paris (ENS Paris), 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, Consiglio Nazionale delle Ricerche (CNR), European Space Agency (ESA)-European Space Agency (ESA), and Low Energy Astrophysics (API, FNWI)

Subjects
STAR-FORMING REGIONS, stars: formation, PACS SPECTROSCOPY, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], astrochemistry, FOS: Physical sciences, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], YOUNG STELLAR OBJECTS, 01 natural sciences, EVOLUTION, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, EXCITATION, WATER, 010306 general physics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), HIFI, HH 46, QB
Abstract

HERSCHEL-HIFI observations of water from the intermediate mass protostar NGC7129 FIRS 2 provide a powerful diagnostic of the physical conditions in this star formation environment. Six spectral settings, covering four H216O and two H218O lines, were observed and all but one H218O line were detected. The four H2 16 O lines discussed here share a similar morphology: a narrower, \approx 6 km/s, component centered slightly redward of the systemic velocity of NGC7129 FIRS 2 and a much broader, \approx 25 km/s component centered blueward and likely associated with powerful outflows. The narrower components are consistent with emission from water arising in the envelope around the intermediate mass protostar, and the abundance of H2O is constrained to \approx 10-7 for the outer envelope. Additionally, the presence of a narrow self-absorption component for the lowest energy lines is likely due to self-absorption from colder water in the outer envelope. The broader component, where the H2O/CO relative abundance is found to be \approx 0.2, appears to be tracing the same energetic region that produces strong CO emission at high J., 6 pages, 4 figures, accepted by A&A

Published
2010
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15. Water in massive star-forming regions: HIFI observations of W3 IRS5

Author

L. Chavarría, F. Herpin, T. Jacq, J. Braine, S. Bontemps, A. Baudry, M. Marseille, F. van der Tak, B. Pietropaoli, F. Wyrowski, R. Shipman, W. Frieswijk, E. F. van Dishoeck, J. Cernicharo, R. Bachiller, M. Benedettini, A. O. Benz, E. Bergin, P. Bjerkeli, G. A. Blake, S. Bruderer, P. Caselli, C. Codella, F. Daniel, A. M. di Giorgio, C. Dominik, S. D. Doty, P. Encrenaz, M. Fich, A. Fuente, T. Giannini, J. R. Goicoechea, Th. de Graauw, P. Hartogh, F. Helmich, G. J. Herczeg, M. R. Hogerheijde, D. Johnstone, J. K. Jørgensen, L. E. Kristensen, B. Larsson, D. Lis, R. Liseau, C. McCoey, G. Melnick, B. Nisini, M. Olberg, B. Parise, J. C. Pearson, R. Plume, C. Risacher, J. Santiago-García, P. Saraceno, J. Stutzki, R. Szczerba, M. Tafalla, A. Tielens, T. A. van Kempen, R. Visser, S. F. Wampfler, J. Willem, U. A. Yıldız, Astronomy, Low Energy Astrophysics (API, FNWI), 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 d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), SRON Netherlands Institute for Space Research (SRON), 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), Max-Planck-Institut für Radioastronomie (MPIFR), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), 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), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), 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), Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], 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, ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), 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), École normale supérieure - Paris (ENS-PSL), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), 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), and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)

Subjects
010504 meteorology & atmospheric sciences, TRACERS, Astronomy, MODELS, FOS: Physical sciences, Astrophysics, 01 natural sciences, Spectral line, ISM: abundances, ABUNDANCES, RADIATIVE-TRANSFER, Abundance (ecology), 0103 physical sciences, Radiative transfer, Isotopologue, Spectral resolution, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), QB, 0105 earth and related environmental sciences, Envelope (waves), Physics, radio lines: ISM, TRAPEZIUM, stars: formation, SPECTROSCOPY, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, extinction, PROTOSTARS, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], ISM: molecules, RATIOS, stars: massive, ENVELOPES, CONTINUUM, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Outflow, dust, dust, extinction
Abstract

We present Herschel observations of the water molecule in the massive star-forming region W3 IRS5. The o-H17O 110-101, p-H18O 111-000, p-H2O 22 202-111, p-H2O 111-000, o-H2O 221-212, and o-H2O 212-101 lines, covering a frequency range from 552 up to 1669 GHz, have been detected at high spectral resolution with HIFI. The water lines in W3 IRS5 show well-defined high-velocity wings that indicate a clear contribution by outflows. Moreover, the systematically blue-shifted absorption in the H2O lines suggests expansion, presumably driven by the outflow. No infall signatures are detected. The p-H2O 111-000 and o-H2O 212-101 lines show absorption from the cold material (T ~ 10 K) in which the high-mass protostellar envelope is embedded. One-dimensional radiative transfer models are used to estimate water abundances and to further study the kinematics of the region. We show that the emission in the rare isotopologues comes directly from the inner parts of the envelope (T > 100 K) where water ices in the dust mantles evaporate and the gas-phase abundance increases. The resulting jump in the water abundance (with a constant inner abundance of 10^{-4}) is needed to reproduce the o-H17O 110-101 and p-H18O 111-000 spectra in our models. We estimate water abundances of 10^{-8} to 10^{-9} in the outer parts of the envelope (T < 100 K). The possibility of two protostellar objects contributing to the emission is discussed., Accepted for publication in the A&A HIFI special issue

Published
2010
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16. Excitation and Abundance of C3 in star forming cores:Herschel/HIFI observations of the sight-lines to W31C and W49N

Author

B. Mookerjea, T. Giesen, J. Stutzki, J. Cernicharo, J. R. Goicoechea, M. De Luca, T. A. Bell, H. Gupta, M. Gerin, C. M. Persson, P. Sonnentrucker, Z. Makai, J. Black, F. Boulanger, A. Coutens, E. Dartois, P. Encrenaz, E. Falgarone, T. Geballe, B. Godard, P. F. Goldsmith, C. Gry, P. Hennebelle, E. Herbst, P. Hily-Blant, C. Joblin, M. Kaźmierczak, R. Kołos, J. Krełowski, D. C. Lis, J. Martin-Pintado, K. M. Menten, R. Monje, J. C. Pearson, M. Perault, T. G. Phillips, R. Plume, M. Salez, S. Schlemmer, M. Schmidt, D. Teyssier, C. Vastel, S. Yu, P. Dieleman, R. Güsten, C. E. Honingh, P. Morris, P. Roelfsema, R. Schieder, A. G. G. M. Tielens, and J. Zmuidzinas

Subjects
Mean kinetic temperature, FOS: Physical sciences, DUST, Astrophysics, HII-REGIONS, SPIRAL-ARM CLOUDS, Atmospheric radiative transfer codes, ABSORPTION, Radiative transfer, Continuum (set theory), IRC+10216, Astrophysics::Galaxy Astrophysics, Line (formation), Physics, SPECTROSCOPY, Line-of-sight, INTERSTELLAR C-3, Triatomic molecule, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, ISM: molecules, H-II-REGIONS, G10.6-0.4, ISM: lines and bands, radiative transfer, Space and Planetary Science, TRANSLUCENT, Astrophysics of Galaxies (astro-ph.GA), ISM: individual objects: W49N, Atomic physics, ISM: individual objects: W31C, Ground state
Abstract

We present spectrally resolved observations of triatomic carbon (C3) in several ro-vibrational transitions between the vibrational ground state and the low-energy nu2 bending mode at frequencies between 1654-1897 GHz along the sight-lines to the submillimeter continuum sources W31C and W49N, using Herschel's HIFI instrument. We detect C3 in absorption arising from the warm envelope surrounding the hot core, as indicated by the velocity peak position and shape of the line profile. The sensitivity does not allow to detect C3 absorption due to diffuse foreground clouds. From the column densities of the rotational levels in the vibrational ground state probed by the absorption we derive a rotation temperature (T_rot) of ~50--70 K, which is a good measure of the kinetic temperature of the absorbing gas, as radiative transitions within the vibrational ground state are forbidden. It is also in good agreement with the dust temperatures for W31C and W49N. Applying the partition function correction based on the derived T_rot, we get column densities N(C3) ~7-9x10^{14} cm^{-2} and abundance x(C3)~10^{-8} with respect to H2. For W31C, using a radiative transfer model including far-infrared pumping by the dust continuum and a temperature gradient within the source along the line of sight we find that a model with x(C3)=10^{-8}, T_kin=30-50 K, N(C3)=1.5 10^{15} cm^{-2} fits the observations reasonably well and provides parameters in very good agreement with the simple excitation analysis., Accepted for publication in Astronomy and Astrophysics (HIFI first results issue)

Published
2010

17. Detection of interstellar oxidaniumyl: Abundant H2O+ towards the star-forming regions DR21, Sgr B2, and NGC6334

Author

C. Joblin, A. Di Giorgio, Olivier Berné, Sylvie Cabrit, Carsten Dominik, S. Pacheco, Paul F. Goldsmith, Charlotte Vastel, H. W. Yorke, Pieter Dieleman, G. Melnick, S.-L. Quin, F. F. S. van der Tak, M. Salez, Nathan R. Crockett, Sandrine Bottinelli, Andrew I. Harris, Doug Johnstone, Patrick W. Morris, Asunción Fuente, Juergen Stutzki, Frank Helmich, Claudio Codella, Sébastien Maret, David A. Neufeld, P. Saraceno, Neil Trappe, Adam Walters, Jonas Zmuidzinas, Robert Simon, Javier R. Goicoechea, C. McCoey, Tom Bell, Pierre Encrenaz, T. Jacq, M. H. D. van der Wiel, D. C. Lis, Carsten Kramer, Simon Bruderer, Pierre Hily-Blant, R. Plume, J. A. Murphy, F. Boulanger, A. Lorenzani, Karl Jacobs, Peter Schilke, Serena Viti, Mihkel Kama, S. Wang, N. Whyborn, Arnold O. Benz, Alain Baudry, Jesús Martín-Pintado, A. C. A. Boogert, Thomas G. Phillips, Stephan Schlemmer, Peter G. Martin, Martin Emprechtinger, K. Demyk, Milena Benedettini, Rolf Güsten, Edwin A. Bergin, Volker Ossenkopf, R. Rizzo, Audrey Coutens, Paola Caselli, D. Teyssier, Valentine Wakelam, Bhaswati Mookerjea, Shanshan Yu, Thomas F. Giesen, N. Crimier, Emmanuel Caux, Karl Schuster, Brunella Nisini, A. Bacman, C. Leinz, Alain Klotz, Claudia Comito, Markus Röllig, Cecilia Ceccarelli, M. Melchior, William D. Langer, A. G. G. M. Tielens, John C. Pearson, F. Daniel, Maryvonne Gerin, José Cernicharo, Geoffrey A. Blake, Holger S. P. Müller, Bertrand Lefloch, S. D. Lord, T. Klein, Karl M. Menten, Berengere Parise, E. Herbst, Marie-Lise Dubernet, Michel Perault, L. Pagani, Edith Falgarone, Claudine Kahane, Laboratoire Univers et Théories (LUTH (UMR_8102)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), SRON Netherlands Institute for Space Research (SRON), California Institute of Technology (CALTECH), Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany, Univ Cologne, Inst Phys 1, Max Planck Institute for Radio Astronomy, Max-Planck-Institut für Extraterrestrische Physik (MPE), Department of Astronomy [Ann Arbor], University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, 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), FORMATION STELLAIRE 2010, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), 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-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)-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 de Bordeaux (UB), Institute of Astronomy [ETH Zürich], Department of Physics [ETH Zürich] (D-PHYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], 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), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), 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), 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), 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), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), 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, Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid 28850, Spain, Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid, École normale supérieure - Paris (ENS Paris), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Cahill Center for Astronomy and Astrophysics, 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), foreign laboratories (FL), CERN [Genève], Ohio State Univ, Dept Phys, Columbus, OH 43210 USA, Ohio State University [Columbus] (OSU), Ohio State Univ, Dept Astron & Chem, Columbus, OH 43210 USA, Leibniz Institute for Crystal Growth, Leibniz Institute, Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7 Canada, Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, Max-Planck-Institut für Radioastronomie (MPIFR), 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), Instituto de RadioAstronomía Milimétrica (IRAM), Centre National de la Recherche Scientifique (CNRS), Laboratoire de Modélisation Multi-échelles des Combustibles (LM2C), Service d'Etudes de Simulation du Comportement du combustibles (SESC), Département d'Etudes des Combustibles (DEC), CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Département d'Etudes des Combustibles (DEC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, KOSMA, I. Physikalisches Institut, Universität zu Köln, CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA, CALTECH, Ctr Infrared Proc & Anal, Pasadena, Osservatorio di Astrofisica di Roma (OAR), Department of Physics and Astronomy [Calgary], University of Calgary, Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Helmholtz zentrum für Schwerionenforschung GmbH (GSI), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Laboratoire de Didactique André Revuz (LDAR (EA_4434)), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université Paris Diderot - Paris 7 (UPD7)-Université d'Artois (UA), AMOR 2010, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Low Energy Astrophysics (API, FNWI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), I. Physikalisches Institut [Köln], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), 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 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), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), 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)-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), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Smithsonian Institution-Harvard University [Cambridge], INAF - Osservatorio Astronomico di Roma (OAR), 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), Universität zu Köln = University of Cologne, 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)-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 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Universiteit Leiden, 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), 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)-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), Harvard University-Smithsonian Institution, Infrared Processing and Analysis Center (IPAC), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Université d'Artois (UA)-Université Paris Diderot - Paris 7 (UPD7)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Astronomy, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-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)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])

Subjects
Experimental Physics, molecular data, Continuum (design consultancy), Rotational transition, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, LASER MAGNETIC-RESONANCE, 01 natural sciences, ISM: clouds, Spectral line, ISM: abundances, 0103 physical sciences, ABSORPTION, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, Hyperfine structure, Astrophysics::Galaxy Astrophysics, QB, Line (formation), Physics, Range (particle radiation), SPECTROSCOPY, IDENTIFICATION, 010308 nuclear & particles physics, astrochemistry, NGC-6334, OH, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, ISM: molecules, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], COMET-KOHOUTEK, Space and Planetary Science, GROUND-STATE, Astrophysics of Galaxies (astro-ph.GA), Outflow, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], EMISSION, ROTATIONAL SPECTRUM, line: identification
Abstract

We identify a prominent absorption feature at 1115 GHz, detected in first HIFI spectra towards high-mass star-forming regions, and interpret its astrophysical origin. The characteristic hyperfine pattern of the H2O+ ground-state rotational transition, and the lack of other known low-energy transitions in this frequency range, identifies the feature as H2O+ absorption against the dust continuum background and allows us to derive the velocity profile of the absorbing gas. By comparing this velocity profile with velocity profiles of other tracers in the DR21 star-forming region, we constrain the frequency of the transition and the conditions for its formation. In DR21, the velocity distribution of H2O+ matches that of the [CII] line at 158\mu\m and of OH cm-wave absorption, both stemming from the hot and dense clump surfaces facing the HII-region and dynamically affected by the blister outflow. Diffuse foreground gas dominates the absorption towards Sgr B2. The integrated intensity of the absorption line allows us to derive lower limits to the H2O+ column density of 7.2e12 cm^-2 in NGC 6334, 2.3e13 cm^-2 in DR21, and 1.1e15 cm^-2 in Sgr B2., Comment: Accepted for publication in A&A

Published
2010
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18. Water abundance variations around high-mass protostars: HIFI observations of the DR21 region

Author

F. F. S. van der Tak, M. G. Marseille, F. Herpin, F. Wyrowski, A. Baudry, S. Bontemps, J. Braine, S. Doty, W. Frieswijk, G. Melnick, R. Shipman, E. F. van Dishoeck, A. O. Benz, P. Caselli, M. Hogerheijde, D. Johnstone, R. Liseau, R. Bachiller, M. Benedettini, E. Bergin, P. Bjerkeli, G. Blake, S. Bruderer, J. Cernicharo, C. Codella, F. Daniel, A. M. di Giorgio, C. Dominik, P. Encrenaz, M. Fich, A. Fuente, T. Giannini, J. Goicoechea, Th. de Graauw, F. Helmich, G. Herczeg, J. Jørgensen, L. Kristensen, B. Larsson, D. Lis, C. McCoey, D. Neufeld, B. Nisini, M. Olberg, B. Parise, J. Pearson, R. Plume, C. Risacher, J. Santiago, P. Saraceno, M. Tafalla, T. van Kempen, R. Visser, S. Wampfler, U. Yıldız, L. Ravera, P. Roelfsema, O. Siebertz, D. Teyssier, Low Energy Astrophysics (API, FNWI), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], 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'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, SRON Netherlands Institute for Space Research (SRON), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Max-Planck-Institut für Radioastronomie (MPIFR), and Astronomy

Subjects
010504 meteorology & atmospheric sciences, LINE EMISSION, Continuum (design consultancy), FOS: Physical sciences, CYGNUS-X, Astrophysics, 01 natural sciences, Spectral line, STAR-FORMATION, RADIATIVE-TRANSFER, ISM: individual objects: DR21, YOUNG STARS, EXCITATION, 0103 physical sciences, ABSORPTION, Radiative transfer, Protostar, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, QB, 0105 earth and related environmental sciences, Line (formation), H-2, Physics, stars: formation, astrochemistry, Star formation, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], MONTE-CARLO METHOD, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, ISM: molecules, EVOLUTION, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Outflow, Galaxy Astrophysics
Abstract

Water is a key molecule in the star formation process, but its spatial distribution in star-forming regions is not well known. We study the distribution of dust continuum and H2O and 13CO line emission in DR21, a luminous star-forming region with a powerful outflow and a compact HII region. Herschel-HIFI spectra near 1100 GHz show narrow 13CO 10-9 emission and H2O 1(11)-0(00) absorption from the dense core and broad emission from the outflow in both lines. The H2O line also shows absorption by a foreground cloud known from ground-based observations of low-J CO lines. The dust continuum emission is extended over 36" FWHM, while the 13CO and H2O lines are confined to ~24" or less. The foreground absorption appears to peak further North than the other components. Radiative transfer models indicate very low abundances of ~2e-10 for H2O and ~8e-7 for 13CO in the dense core, and higher H2O abundances of ~4e-9 in the foreground cloud and ~7e-7 in the outflow. The high H2O abundance in the warm outflow is probably due to the evaporation of water-rich icy grain mantles, while the H2O abundance is kept down by freeze-out in the dense core and by photodissociation in the foreground cloud., Comment: Accepted by A&A Letters (Herschel special issue); 4 pages, 4 figures

Published
2010
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19. Herschel observations of EXtra-Ordinary Sources (HEXOS): Observations of H2O and its isotopologues towards Orion KL

Author

Pierre Encrenaz, Doug Johnstone, S. D. Lord, Volker Tolls, Edith Falgarone, John C. Pearson, Marie-Lise Dubernet, Michel Perault, D. C. Lis, Javier R. Goicoechea, Geoffrey A. Blake, William D. Langer, Laurent Pagani, Shanshan Yu, Edwin Bergin, S.-L. Qin, Gary J. Melnick, C. Joblin, Volker Ossenkopf, David A. Neufeld, Thomas F. Giesen, Peter G. Martin, Charlotte Vastel, Patrick W. Morris, J. A. Murphy, Martin Emprechtinger, Neil Trappe, W. D. Latter, Nathan R. Crockett, Paul F. Goldsmith, Harold W. Yorke, M. Salez, Sébastien Maret, Peter Schilke, Stephan Schlemmer, S. Wang, Jonas Zmuidzinas, Maryvonne Gerin, F. F. S. van der Tak, José Cernicharo, Holger S. P. Müller, R. Plume, F. Daniel, Juergen Stutzki, Tom Bell, Emmanuel Caux, Karl M. Menten, Cecilia Ceccarelli, Thomas G. Phillips, E. Herbst, Sylvie Cabrit, Claudia Comito, Astronomy, Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Department of Astronomy [Ann Arbor], University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, California Institute of Technology (CALTECH), 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 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), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-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 Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-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)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), CNRS INSU, UMR 5187, F-31028 Toulouse 4, France, UMR 5187 Toulouse, 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), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Max Planck Institute for Radio Astronomy, Université Paris sciences et lettres (PSL), Cahill Center for Astronomy and Astrophysics, 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), Ohio State Univ, Dept Phys, Columbus, OH 43210 USA, Ohio State University [Columbus] (OSU), Ohio State Univ, Dept Astron & Chem, Columbus, OH 43210 USA, Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7 Canada, Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, Laboratoire de Modélisation Multi-échelles des Combustibles (LM2C), Service d'Etudes de Simulation du Comportement du combustibles (SESC), Département d'Etudes des Combustibles (DEC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Département d'Etudes des Combustibles (DEC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Max-Planck-Institut für Radioastronomie (MPIFR), Infrared Processing and Analysis Center (IPAC), 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), SRON Netherlands Institute for Space Research (SRON), foreign laboratories (FL), CERN [Genève], Department of Physics and Astronomy [Calgary], University of Calgary, I. Physikalisches Institut [Köln], Universität zu Köln = University of Cologne, Laboratoire de Didactique André Revuz (LDAR (EA_4434)), Université d'Artois (UA)-Université Paris Diderot - Paris 7 (UPD7)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Harvard University-Smithsonian Institution, Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), 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 Paris), Univ Toulouse UPS, Ctr Etud Spatiale Rayonnements, F-31062 Toulouse 9, France, Centre Etud Spatiale Rayonnements Toulouse, 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), CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA, CALTECH, Ctr Infrared Proc & Anal, Pasadena, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Universität zu Köln, Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université Paris Diderot - Paris 7 (UPD7)-Université d'Artois (UA), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), 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), Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid 28850, Spain, Ctr Astrobiol CSIC INTA, Lab Astrofis Mol, Madrid, 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), CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction de l'Energie Nucléaire (CEA-DEN), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany, and Univ Cologne, Inst Phys 1

Subjects
Opacity, Experimental Physics, FOS: Physical sciences, Astrophysics, 01 natural sciences, ISM: abundances, Abundance (ecology), 0103 physical sciences, Isotopologue, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, Line (formation), Physics, geography, Line-of-sight, Plateau, geography.geographical_feature_category, 010308 nuclear & particles physics, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, ISM: molecules, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Sublimation (phase transition), [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA]
Abstract

We report the detection of more than 48 velocity-resolved ground rotational state transitions of H2(16)O, H2(18)O, and H2(17)O - most for the first time - in both emission and absorption toward Orion KL using Herschel/HIFI. We show that a simple fit, constrained to match the known emission and absorption components along the line of sight, is in excellent agreement with the spectral profiles of all the water lines. Using the measured H2(18)O line fluxes, which are less affected by line opacity than their H2(16)O counterparts, and an escape probability method, the column densities of H2(18)O associated with each emission component are derived. We infer total water abundances of 7.4E-5, 1.0E-5, and 1.6E-5 for the plateau, hot core, and extended warm gas, respectively. In the case of the plateau, this value is consistent with previous measures of the Orion-KL water abundance as well as those of other molecular outflows. In the case of the hot core and extended warm gas, these values are somewhat higher than water abundances derived for other quiescent clouds, suggesting that these regions are likely experiencing enhanced water-ice sublimation from (and reduced freeze-out onto) grain surfaces due to the warmer dust in these sources., Comment: 5 pages, 2 figures

Published
2010
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20. Water abundances in high-mass protostellar envelopes: Herschel observations with HIFI

Author

M. G. Marseille, F. F. S. van der Tak, F. Herpin, F. Wyrowski, L. Chavarría, B. Pietropaoli, A. Baudry, S. Bontemps, J. Cernicharo, T. Jacq, W. Frieswijk, R. Shipman, E. F. van Dishoeck, R. Bachiller, M. Benedettini, A. O. Benz, E. Bergin, P. Bjerkeli, G. A. Blake, J. Braine, S. Bruderer, P. Caselli, E. Caux, C. Codella, F. Daniel, P. Dieleman, A. M. di Giorgio, C. Dominik, S. D. Doty, P. Encrenaz, M. Fich, A. Fuente, T. Gaier, T. Giannini, J. R. Goicoechea, Th. de Graauw, F. Helmich, G. J. Herczeg, M. R. Hogerheijde, B. Jackson, H. Javadi, W. Jellema, D. Johnstone, J. K. Jørgensen, D. Kester, L. E. Kristensen, B. Larsson, W. Laauwen, D. Lis, R. Liseau, W. Luinge, C. McCoey, A. Megej, G. Melnick, D. Neufeld, B. Nisini, M. Olberg, B. Parise, J. C. Pearson, R. Plume, C. Risacher, P. Roelfsema, J. Santiago-García, P. Saraceno, P. Siegel, J. Stutzki, M. Tafalla, T. A. van Kempen, R. Visser, S. F. Wampfler, U. A. Yıldız, Low Energy Astrophysics (API, FNWI), 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, SRON Netherlands Institute for Space Research (SRON), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Max-Planck-Institut für Radioastronomie (MPIFR), and Astronomy

Subjects
010504 meteorology & atmospheric sciences, Astronomy, FOS: Physical sciences, Astrophysics, 01 natural sciences, ISM: abundances, STAR-FORMATION, REGION, RADIATIVE-TRANSFER, Abundance (ecology), EXCITATION, 0103 physical sciences, Radiative transfer, H2O, Protostar, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, QB, 0105 earth and related environmental sciences, Envelope (waves), Line (formation), Physics, Line-of-sight, extinction, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Star formation, Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, MONTE-CARLO METHOD, PROTOSTARS, CORES, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, ISM: molecules, EVOLUTION, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, dust, extinction, dust, EMISSION, Galaxy Astrophysics
Abstract

We derive the dense core structure and the water abundance in four massive star-forming regions which may help understand the earliest stages of massive star formation. We present Herschel-HIFI observations of the para-H2O 1_11-0_00 and 2_02-1_11 and the para-H2-18O 1_11-0_00 transitions. The envelope contribution to the line profiles is separated from contributions by outflows and foreground clouds. The envelope contribution is modelled using Monte-Carlo radiative transfer codes for dust and molecular lines (MC3D and RATRAN), with the water abundance and the turbulent velocity width as free parameters. While the outflows are mostly seen in emission in high-J lines, envelopes are seen in absorption in ground-state lines, which are almost saturated. The derived water abundances range from 5E-10 to 4E-8 in the outer envelopes. We detect cold clouds surrounding the protostar envelope, thanks to the very high quality of the Herschel-HIFI data and the unique ability of water to probe them. Several foreground clouds are also detected along the line of sight. The low H2O abundances in massive dense cores are in accordance with the expectation that high densities and low temperatures lead to freeze-out of water on dust grains. The spread in abundance values is not clearly linked to physical properties of the sources., Comment: 8 pages, 5 figures, accepted for publication the 15/07/2010 by Astronomy&Astrophysics as a letter in the Herschel-HIFI special issue

Published
2010
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21. Physical structure of the envelopes of intermediate-mass protostars

Author

J. R. Rizzo, N. Crimier, Paola Caselli, Claudine Kahane, Cecilia Ceccarelli, E. F. van Dishoeck, R. Plume, Bertrand Lefloch, T. Alonso-Albi, Doug Johnstone, Sébastien Maret, M. Tafalla, Asunción Fuente, Friedrich Wyrowski, Laboratoire d'Astrophysique de Grenoble (LAOG), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Mass star, 010308 nuclear & particles physics, Radiation field, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Power law, Physical structure, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Radiative transfer, Astrophysics::Solar and Stellar Astrophysics, Protostar, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS
Abstract

Context: Intermediate mass protostars provide a bridge between low- and high-mass protostars. Furthermore, they are an important component of the UV interstellar radiation field. Despite their relevance, little is known about their formation process. Aims: We present a systematic study of the physical structure of five intermediate mass, candidate Class 0 protostars. Our two goals are to shed light on the first phase of intermediate mass star formation and to compare these protostars with low- and high-mass sources. Methods: We derived the dust and gas temperature and density profiles of the sample. We analysed all existing continuum data on each source and modelled the resulting SED with the 1D radiative transfer code DUSTY. The gas temperature was then predicted by means of a modified version of the code CHT96. Results: We found that the density profiles of five out of six studied intermediate mass envelopes are consistent with the predictions of the "inside-out" collapse theory.We compared several physical parameters, like the power law index of the density profile, the size, the mass, the average density, the density at 1000 AU and the density at 10 K of the envelopes of low-, intermediate, and high-mass protostars. When considering these various physical parameters, the transition between the three groups appears smooth, suggesting that the formation processes and triggers do not substantially differ.

Published
2010

22. Herschel observations of the hydroxyl radical (OH) in young stellar objects

Author

S. F. Wampfler, G. J. Herczeg, S. Bruderer, A. O. Benz, E. F. van Dishoeck, L. E. Kristensen, R. Visser, S. D. Doty, M. Melchior, T. A. van Kempen, U. A. Yıldız, C. Dedes, J. R. Goicoechea, A. Baudry, G. Melnick, R. Bachiller, M. Benedettini, E. Bergin, P. Bjerkeli, G. A. Blake, S. Bontemps, J. Braine, P. Caselli, J. Cernicharo, C. Codella, F. Daniel, A. M. di Giorgio, C. Dominik, P. Encrenaz, M. Fich, A. Fuente, T. Giannini, Th. de Graauw, F. Helmich, F. Herpin, M. R. Hogerheijde, T. Jacq, D. Johnstone, J. K. Jørgensen, B. Larsson, D. Lis, R. Liseau, M. Marseille, C. Mc Coey, D. Neufeld, B. Nisini, M. Olberg, B. Parise, J. C. Pearson, R. Plume, C. Risacher, J. Santiago-García, P. Saraceno, R. Shipman, M. Tafalla, F. F. S. van der Tak, F. Wyrowski, P. Roelfsema, W. Jellema, P. Dieleman, E. Caux, J. Stutzki, 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), 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 d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), 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 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), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), SRON Netherlands Institute for Space Research (SRON), INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], 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, ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Max-Planck-Institut für Radioastronomie (MPIFR), Low Energy Astrophysics (API, FNWI), École normale supérieure - Paris (ENS-PSL), 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 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), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), and Astronomy

Subjects
Young stellar object, Astronomy, Flux, FOS: Physical sciences, Astrophysics, MOLECULAR CLOUD, CO OBSERVATIONS, 01 natural sciences, PHYSICAL STRUCTURE, Luminosity, chemistry.chemical_compound, Far infrared, 0103 physical sciences, Solar and Stellar Astrophysics, 010306 general physics, Absorption (electromagnetic radiation), Spectroscopy, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Line (formation), QB, Physics, stars: formation, PACS SPECTROSCOPY, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, astrochemistry, MASS PROTOSTARS, Astronomy and Astrophysics, CLASS-0 SOURCES, PHOTODISSOCIATION, FIRS 2, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], ISM: molecules, ISM: jets and outflows, chemistry, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, ISM: individual objects: HH 46, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Hydroxyl radical, EMISSION, HH 46
Abstract

Water in Star-forming regions with Herschel (WISH) is a Herschel Key Program investigating the water chemistry in young stellar objects (YSOs) during protostellar evolution. Hydroxyl (OH) is one of the reactants in the chemical network most closely linked to the formation and destruction of H2O. High-temperature chemistry connects OH and H2O through the OH + H2 H2O + H reactions. Formation of H2O from OH is efficient in the high-temperature regime found in shocks and the innermost part of protostellar envelopes. Moreover, in the presence of UV photons, OH can be produced from the photo-dissociation of H2O. High-resolution spectroscopy of the OH 163.12 micron triplet towards HH 46 and NGC 1333 IRAS 2A was carried out with the Heterodyne Instrument for the Far Infrared (HIFI) on board Herschel. The low- and intermediate-mass YSOs HH 46, TMR 1, IRAS 15398-3359, DK Cha, NGC 7129 FIRS 2, and NGC 1333 IRAS 2A were observed with the Photodetector Array Camera and Spectrometer (PACS) in four transitions of OH and two [OI] lines. The OH transitions at 79, 84, 119, and 163 micron and [OI] emission at 63 and 145 micron were detected with PACS towards the class I low-mass YSOs as well as the intermediate-mass and class I Herbig Ae sources. No OH emission was detected from the class 0 YSO NGC 1333 IRAS 2A, though the 119 micron was detected in absorption. With HIFI, the 163.12 micron was not detected from HH 46 and only tentatively detected from NGC 1333 IRAS 2A. The combination of the PACS and HIFI results for HH 46 constrains the line width (FWHM > 11 km/s) and indicates that the OH emission likely originates from shocked gas. This scenario is supported by trends of the OH flux increasing with the [OI] flux and the bolometric luminosity. Similar OH line ratios for most sources suggest that OH has comparable excitation temperatures despite the different physical properties of the sources., Comment: Accepted for publication in Astronomy and Astrophysics (Herschel special issue)

Published
2010
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23. Mapping the column density and dust temperature structure of IRDCs with Herschel [Letter]

Author

Alessio Traficante, Jason M. Kirk, F. Faustini, P. Martin, J. A. Rodón, L. A. Montier, Frédérique Motte, R. Plume, Derek Ward-Thompson, C. Lenfestey, Maria T. Beltrán, L. Calzoletti, Sergio Molinari, Nicolas Peretto, Howard A. Smith, J.-P. Bernard, Gary A. Fuller, L. D. Anderson, Cara Battersby, M. Veneziani, I. Ristorcelli, A. M. DiGiorgio, John Bally, D. J. Marshall, L. A. Wilcock, Laboratoire d'Astrophysique de Marseille (LAM), and 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)

Subjects
Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Star formation, Infrared, Molecular cloud, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Galactic plane, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Isothermal process, Stars, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Thermal, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, QB
Abstract

Infrared dark clouds (IRDCs) are cold and dense reservoirs of gas potentially available to form stars. Many of these clouds are likely to be pristine structures representing the initial conditions for star formation. The study presented here aims to construct and analyze accurate column density and dust temperature maps of IRDCs by using the first Herschel data from the Hi-GAL galactic plane survey. These fundamental quantities, are essential for understanding processes such as fragmentation in the early stages of the formation of stars in molecular clouds. We have developed a simple pixel-by-pixel SED fitting method, which accounts for the background emission. By fitting a grey-body function at each position, we recover the spatial variations in both the dust column density and temperature within the IRDCs. This method is applied to a sample of 22 IRDCs exhibiting a range of angular sizes and peak column densities. Our analysis shows that the dust temperature decreases significantly within IRDCs, from background temperatures of 20-30 K to minimum temperatures of 8-15 K within the clouds, showing that dense molecular clouds are not isothermal. Temperature gradients have most likely an important impact on the fragmentation of IRDCs. Local temperature minima are strongly correlated with column density peaks, which in a few cases reach NH2 = 1 x 10^{23} cm^{-2}, identifying these clouds as candidate massive prestellar cores. Applying this technique to the full Hi-GAL data set will provide important constraints on the fragmentation and thermal properties of IRDCs, and help identify hundreds of massive prestellar core candidates., Accepted for publication in A&A Herschel special issue

Published
2010
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24. Herschel observations of the W43 'mini-starburst'

Author

Yancy L. Shirley, Cara Battersby, M. Veneziani, Sergio Molinari, Frédérique Motte, Annie Zavagno, Alessio Traficante, Peter Schilke, Wayne Schlingman, A. M. DiGiorgio, Adam Ginsburg, J. A. Rodón, Q. Nguyen-Luong, Jin-Zeng Li, John Bally, Leonardo Testi, M. R. Pestalozzi, R. Plume, F. Faustini, Guy S. Stringfellow, N. Schneider-Bontemps, L. D. Anderson, L. Calzoletti, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Canadian Institute for Theoretical Astrophysics (CITA), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Department of Physics and Astronomy [Calgary], University of Calgary, Laboratoire d'Astrophysique de Marseille (LAM), 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), Max-Planck-Institut für Radioastronomie (MPIFR), European Southern Observatory (ESO), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Beaussier, Catherine, 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), National Astronomical Observatories [Beijing] (NAOC), Chinese Academy of Sciences [Beijing] (CAS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Consiglio Nazionale delle Ricerche (CNR), Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany, Univ Cologne, Inst Phys 1, Max Planck Institute for Radio Astronomy, Observatoire Astronomique de Marseille Provence (OAMP), Université de Provence - Aix-Marseille 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), I. Physikalisches Institut [Köln], Universität zu Köln, and Universität zu Köln = University of Cologne

Subjects
010504 meteorology & atmospheric sciences, Infrared, Hii regions, Continuum (design consultancy), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Luminosity, Spitzer Space Telescope, 0103 physical sciences, Protostar, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, infrared: ISM, stars: protostars, [PHYS.ASTR.GA] Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Astronomy and Astrophysics, Galactic plane, Astrophysics - Astrophysics of Galaxies, Radial velocity, stars: massive, Stars, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Astrophysics::Earth and Planetary Astrophysics, [SDU.ASTR.GA] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], ISM: individual objects: W43
Abstract

Aims: To explore the infrared and radio properties of one of the closest Galactic starburst regions. Methods: Images obtained with the Herschel Space Observatory at wavelengths of 70, 160, 250, 350, and 500 microns using the PACS and SPIRE arrays are analyzed and compared with radio continuum VLA data and 8 micron images from the Spitzer Space Telescope. The morphology of the far-infrared emission is combined with radial velocity measurements of millimeter and centimeter wavelength transitions to identify features likely to be associated with the W43 complex. Results: The W43 star-forming complex is resolved into a dense cluster of protostars, infrared dark clouds, and ridges of warm dust heated by massive stars. The 4 brightest compact sources with L > 1.5 x 10^4 Lsun embedded within the Z-shaped ridge of bright dust emission in W43 remain single at 4" (0.1 pc) resolution. These objects, likely to be massive protostars or compact clusters in early stages of evolution are embedded in clumps with masses of 10^3 to 10^4 Msun, but contribute only 2% to the 3.6 x 10^6 Lsun far-IR luminosity of W43 measured in a 16 by 16 pc box. The total mass of gas derived from the far-IR dust emission inside this region is ~10^6 Msun. Cometary dust clouds, compact 6 cm radio sources, and warm dust mark the locations of older populations of massive stars. Energy release has created a cavity blowing-out below the Galactic plane. Compression of molecular gas in the plane by the older HII region near G30.684-0.260 and the bipolar structure of the resulting younger W43 HII region may have triggered the current mini-star burst., 5 pages, 3 figures, accepted for A&A Special Issue

Published
2010
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25. Strong absorption by interstellar hydrogen fluoride: Herschel/HIFI observations of the sight-line to G10.6-0.4 (W31C)

Author

M. De Luca, Bhaswati Mookerjea, Charlotte Vastel, René Liseau, E. Herbst, Pierre Encrenaz, C. Joblin, Javier R. Goicoechea, Jesús Martín-Pintado, Juergen Stutzki, Patrick W. Morris, P. Cais, David A. Neufeld, Paul F. Goldsmith, Maryvonne Gerin, Stephan Schlemmer, Mark B. Schmidt, José Cernicharo, Shanshan Yu, M. Kazmierczak, P. Planesas, D. Teyssier, Edith Falgarone, M. Salez, Patrick Hennebelle, Harshal Gupta, Robert Kołos, Audrey Coutens, Emmanuel Caux, John C. Pearson, F. Boulanger, Karl M. Menten, Michel Perault, Paule Sonnentrucker, John H. Black, Emmanuel Dartois, Tom Bell, B. Godard, Jacek Krełowski, Raquel Monje, Thomas R. Geballe, Carina M. Persson, Pierre Hily-Blant, Thomas G. Phillips, Cecile Gry, R. Plume, Dariusz C. Lis, Thomas F. Giesen, 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), California Institute of Technology (CALTECH), 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 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), 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)-Centre National d’Études Spatiales [Paris] (CNES), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Laboratoire d'Astrophysique de Marseille (LAM), 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), Indian Institute of Technology Delhi (IIT Delhi), Ohio State University [Columbus] (OSU), 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), Max-Planck-Institut für Radioastronomie (MPIFR), KOSMA, I. Physikalisches Institut, Universität zu Köln = University of Cologne, Department of Materials Science and Engineering, KTH (KTH), Department of Materials Science and Engineering, KTH, Department of Obstetrics and Gynecology, J. Gutenberg-University, Herschel Science Center [Madrid], European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), 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 (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), École normale supérieure - Paris (ENS Paris), 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), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), 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, Universität zu Köln, European Space Agency (ESA)-European Space Agency (ESA), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université Sciences et Technologies - Bordeaux 1

Subjects
Exothermic reaction, Hydrogen, chemistry.chemical_element, FOS: Physical sciences, Astrophysics, 7. Clean energy, 01 natural sciences, Dual beam, chemistry.chemical_compound, 0103 physical sciences, Thermochemistry, 010306 general physics, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Physics, Sideband, [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], Hydrogen fluoride, Astrophysics - Astrophysics of Galaxies, ISM: molecules, molecular processes, Sight line, chemistry, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Fluorine, submillimeter: ISM, Atomic physics
Abstract

We report the detection of strong absorption by interstellar hydrogen fluoride along the sight-line to the submillimeter continuum source G10.6-0.4 (W31C). We have used Herschel's HIFI instrument, in dual beam switch mode, to observe the 1232.4763 GHz J=1-0 HF transition in the upper sideband of the Band 5a receiver. The resultant spectrum shows weak HF emission from G10.6-0.4 at LSR velocities in the range -10 to -3 km/s, accompanied by strong absorption by foreground material at LSR velocities in the range 15 to 50 km/s. The spectrum is similar to that of the 1113.3430 GHz 1(11)-0(00) transition of para-water, although at some frequencies the HF (hydrogen fluoride) optical depth clearly exceeds that of para-H2O. The optically-thick HF absorption that we have observed places a conservative lower limit of 1.6E+14 cm-2 on the HF column density along the sight-line to G10.6-0.4. Our lower limit on the HF abundance, 6E-9 relative to hydrogen nuclei, implies that hydrogen fluoride accounts for between ~ 30 and 100% of the fluorine nuclei in the gas phase along this sight-line. This observation corroborates theoretical predictions that - because the unique thermochemistry of fluorine permits the exothermic reaction of F atoms with molecular hydrogen - HF will be the dominant reservoir of interstellar fluorine under a wide range of conditions., Comment: Accepted for publication in Astronomy and Astrophysics (Herschel special issue). This revised version corrects a typographic error in the HTML abstract, in which the lower limit on the HF abundance (should be 6E-9) was previously misstated. The abstract in the PDF version is correct and the latter has not been modified

Published
2010
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26. Herschel/HIFI observations of high-J CO lines in the NGC 1333 low-mass star-forming region

Author

Fabrice Herpin, José Cernicharo, Carsten Dominik, A. Di Giorgio, T. Jacq, Pierre Encrenaz, Doug Johnstone, Claudio Codella, Steven D. Doty, M. Fich, F. F. S. van der Tak, Jes K. Jørgensen, Gregory J. Herczeg, Volker Ossenkopf, Paola Caselli, S. F. Wampfler, M. Marseille, Edwin Bergin, Per Bjerkeli, T. A. van Kempen, Michiel R. Hogerheijde, Sylvain Bontemps, Jonathan Braine, Alain Baudry, Asunción Fuente, Juergen Stutzki, J. Santiago-Garcia, E. Deul, Ruud Visser, Willem Jellema, René Liseau, Javier R. Goicoechea, Paolo Saraceno, Christophe Risacher, Umut A. Yildiz, David A. Neufeld, Berengere Parise, Milena Benedettini, Pieter Dieleman, Frank Helmich, E. F. van Dishoeck, R. Schieder, John C. Pearson, Dariusz C. Lis, Lars E. Kristensen, F.-C. Liu, T. Giannini, Arnold O. Benz, F. Daniel, Friedrich Wyrowski, Rafael Bachiller, Geoffrey A. Blake, Russel Shipman, Alexander G. G. M. Tielens, Th. de Graauw, Michael Olberg, Gary J. Melnick, C. McCoey, B. Larsson, Brunella Nisini, R. Plume, M. Tafalla, Simon Bruderer, 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 d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), 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), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), 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), SRON Netherlands Institute for Space Research (SRON), INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], 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, ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Radioastronomie (MPIFR), Astronomy, 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), École normale supérieure - Paris (ENS-PSL), 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), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), and Low Energy Astrophysics (API, FNWI)

Subjects
010504 meteorology & atmospheric sciences, Astronomy, Evaporation, FOS: Physical sciences, DUST, Astrophysics, Star (graph theory), 01 natural sciences, DENSE CORES, 0103 physical sciences, Radiative transfer, Protostar, WATER, Solar and Stellar Astrophysics, Isotopologue, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), QB, 0105 earth and related environmental sciences, Envelope (waves), Line (formation), Physics, stars: formation, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], astrochemistry, NGC-1333 IRAS-4, PROTOSTARS, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], H2CO, ISM: molecules, EVOLUTION, ENVELOPES, ISM: jets and outflows, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, ABUNDANCE, Low Mass, HIFI
Abstract

Herschel-HIFI observations of high-J lines (up to J_u=10) of 12CO, 13CO and C18O are presented toward three deeply embedded low-mass protostars, NGC 1333 IRAS 2A, IRAS 4A, and IRAS 4B, obtained as part of the Water In Star-forming regions with Herschel (WISH) key program. The spectrally-resolved HIFI data are complemented by ground-based observations of lower-J CO and isotopologue lines. The 12CO 10-9 profiles are dominated by broad (FWHM 25-30 km s^-1) emission. Radiative transfer models are used to constrain the temperature of this shocked gas to 100-200 K. Several CO and 13CO line profiles also reveal a medium-broad component (FWHM 5-10 km s^-1), seen prominently in H2O lines. Column densities for both components are presented, providing a reference for determining abundances of other molecules in the same gas. The narrow C18O 9-8 lines probe the warmer part of the quiescent envelope. Their intensities require a jump in the CO abundance at an evaporation temperature around 25 K, thus providing new direct evidence for a CO ice evaporation zone around low-mass protostars., Comment: 8 pages, 9 figures

Published
2010
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27. Variations in H2O+/H2O ratios toward massive star-forming regions

Author

Carsten Dominik, Michiel R. Hogerheijde, Doug Johnstone, Claudio Codella, Steven D. Doty, Michael Olberg, Th. de Graauw, Rafael Bachiller, M. Marseille, Christophe Risacher, Gary J. Melnick, Pierre Encrenaz, Russel Shipman, J. Santiago, Javier R. Goicoechea, R. Plume, Jes K. Jørgensen, M. Benedettini, T. Jacq, Geoffrey A. Blake, S. F. Wampfler, Lars E. Kristensen, Jonathan Braine, Wilfred Frieswijk, Gregory J. Herczeg, Frank Helmich, Maryvonne Gerin, T. Giannini, Pieter R. Roelfsema, Umut A. Yildiz, Berengere Parise, Pieter Dieleman, A. Di Giorgio, Simon Bruderer, John H. Black, de A Jonge, M. Fich, D. C. Lis, John C. Pearson, Edwin Bergin, L. Chavarria, Per Bjerkeli, T. A. van Kempen, Friedrich Wyrowski, Paolo Saraceno, Fabrice Herpin, M. Tafalla, F. F. S. van der Tak, Sylvain Bontemps, René Liseau, José Cernicharo, E. Falgarone, D. A. Beintema, Asunción Fuente, Juergen Stutzki, F. Daniel, Ruud Visser, Volker Ossenkopf, Paola Caselli, Arnold O. Benz, N. Whyborn, Alain Baudry, E. F. van Dishoeck, C. McCoey, B. Larsson, Brunella Nisini, Low Energy Astrophysics (API, FNWI), Max-Planck-Institut für Radioastronomie (MPIFR), 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 d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), SRON Netherlands Institute for Space Research (SRON), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), 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), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), 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), INAF - Osservatorio Astronomico di Roma (OAR), Onsala Space Observatory, Chalmers University of Technology [Göteborg], 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, ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), 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), 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), École normale supérieure - Paris (ENS-PSL), 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), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), 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), and Astronomy

Subjects
FOS: Physical sciences, LINE, Astrophysics, LASER MAGNETIC-RESONANCE, Star (graph theory), ISM: clouds, 01 natural sciences, CHEMISTRY, 0103 physical sciences, Cluster (physics), Protostar, 010306 general physics, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, QB, Physics, stars: formation, Line-of-sight, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], DR21, ASTRONOMY, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, ISM: molecules, W51, Interstellar medium, Stars, Early results, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), SIGHT, submillimeter: ISM, HIFI, Galaxy Astrophysics
Abstract

Early results from the Herschel Space Observatory revealed the water cation H2O+ to be an abundant ingredient of the interstellar medium. Here we present new observations of the H2O and H2O+ lines at 1113.3 and 1115.2 GHz using the Herschel Space Observatory toward a sample of high-mass star-forming regions to observationally study the relation between H2O and H2O+ . Nine out of ten sources show absorption from H2O+ in a range of environments: the molecular clumps surrounding the forming and newly formed massive stars, bright high-velocity outflows associated with the massive protostars, and unrelated low-density clouds along the line of sight. Column densities per velocity component of H2 O+ are found in the range of 10^12 to a few 10^13 cm-2 . The highest N(H2O+) column densities are found in the outflows of the sources. The ratios of H2O+/H2O are determined in a range from 0.01 to a few and are found to differ strongly between the observed environments with much lower ratios in the massive (proto)cluster envelopes (0.01-0.1) than in outflows and diffuse clouds. Remarkably, even for source components detected in H2O in emission, H2O+ is still seen in absorption., Comment: 5 pages, 4 figures, accepted for publication as a letter in the A&A Herschel-HIFI special issue

Published
2010
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28. Odin observations of H2O in the Galactic Centre

Author

E. M. Gregersen, George F. Mitchell, Pierre Encrenaz, P. A. Feldman, Alain Lecacheux, Kalevi Mattila, A. O. H. Olofsson, M. Olberg, Nicholas F. H Tothill, Charles L. Curry, Roy Booth, Urban Frisk, Sun Kwok, B. Larsson, Per Bergman, Kevin Volk, A. Winnberg, M. Lindqvist, Christine D. Wilson, I. Ristorcelli, G. Olofsson, Åke Hjalmarson, M. Fich, R. Plume, Maryvonne Gerin, Fredrik von Schéele, T. Liljeström, Edith Falgarone, John H. Black, Tatsuhiko I. Hasegawa, V. Buat, L. Nordh, René Liseau, H. G. Floren, Jorma Harju, G. Serra, Aa. Sandqvist, L. E. B. Johansson, Laurent Pagani, 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), Physique des plasmas, 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)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, 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), and Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Spiral galaxy, Absorption spectroscopy, 010308 nuclear & particles physics, Molecular cloud, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Space and Planetary Science, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Emission spectrum, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics
Abstract

The Odin satellite has been used to detect emission and absorption in the 557-GHz H2O line in the Galactic Centre towards the Sgr A* Circumnuclear Disk (CND), and the Sgr A +20 km/s and +50 km/s molecular clouds. Strong broad H2O emission lines have been detected in all three objects. Narrow H2O absorption lines are present at all three positions and originate along the lines of sight in the 3-kpc Spiral Arm, the -30 km/s Spiral Arm and the Local Sgr Spiral Arm. Broad H2O absorption lines near -130 km/s are also observed, originating in the Expanding Molecular Ring. A new molecular feature (the ``High Positive Velocity Gas'' - HPVG) has been identified in the positive velocity range of ~ +120 to +220 km/s, seen definitely in absorption against the stronger dust continuum emission from the +20 km/s and +50 km/s clouds and possibly in emission towards the position of Sgr A* CND. The 548-GHz H2_18O isotope line towards the CND is not detected at the 0.02 K (rms) level., 5 pages, 3 figures, accepted by A&A, special Odin Letters issue

Published
2003
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29. The Coalsack near and far

Author

Henrik Beuther, Th. Henning, Fabian Heitsch, R. Plume, and Jouni Kainulainen

Subjects
Physics, Star formation, Molecular cloud, Extinction (astronomy), FOS: Physical sciences, Velocity dispersion, Astronomy and Astrophysics, Context (language use), Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics - Solar and Stellar Astrophysics, Thermal velocity, Space and Planetary Science, Gravitational collapse, Low Mass, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract

Context: The large Coalsack dark cloud is one of the rare molecular clouds without clear signs of star formation. Aims: We investigate the dynamical properties of the gas within the Coalsack. Methods: The two highest extinction regions were mapped with the APEX telescope in 13CO(2-1) comprising a region of ~1 square degree. Results: In addition to the well-known, nearby gas component around -4km/s, we identified additional molecular gas components - in particular a second extended molecular cloud at a velocity of ~-30km/s and an estimated distance of ~3.1kpc - that dominate the column density and visual extinction distributions in the northeastern part of the Coalsack. Although comprising ~2600Msun, the mass of this distant cloud is distributed over an extent of ~73pc, much larger than typical high-mass infrared dark clouds. Its filamentary structure is consistent with a compressible gaseous self-gravitating cylinder, and its low mass per length indicates that it may be stable against gravitational collapse. We find barely any mid-infrared emission in archival MSX data, which is indicative of almost no star-formation activity in the near and far cloud complexes. The nearby clouds have narrow, almost thermal velocity dispersions with median values between 0.2 and 0.4km/s, which is also consistent with low star-formation activity. Only Tapia's Globule 2 exhibits a velocity dispersion increase toward the extinction peak and peak-velocity gradients over the core, which is indicative of a state of elevated dynamical properties. Conclusions: The Coalsack is not one single coherent structure, but consists of several cloud complexes nearby as well as at several kpc distance. All studied clouds appear as starless low-turbulence regions that may not even collapse in the future. Only one globule exhibits more dynamical signatures and is a good candidate for present/future star formation., Comment: 9 pages, 11 figures accepted for A&A, available also at http://www.mpia-hd.mpg.de/homes/beuther/papers.html

Published
2011
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30. The JCMT Spectral Legacy Survey: physical structure of the molecular envelope of the high-mass protostar AFGL2591

Author

J. L. Williams, F. F. S. van der Tak, Marco Spaans, Gary A. Fuller, R. Plume, H. Roberts, M. H. D. van der Wiel, and Astronomy

Subjects
ROTATIONAL-EXCITATION, medicine.medical_specialty, FOS: Physical sciences, CYGNUS-X, Astrophysics, DENSE CORES, CHEMISTRY, medicine, Radiative transfer, Astrophysics::Solar and Stellar Astrophysics, Protostar, OUTFLOW, Astrophysics::Galaxy Astrophysics, Optical depth, Line (formation), Envelope (waves), STAR-FORMING REGIONS, Physics, stars: formation, ISM: individual objects: AFGL2591, MONTE-CARLO METHOD, Astronomy and Astrophysics, YOUNG STELLAR OBJECTS, Astrophysics - Astrophysics of Galaxies, LINE OBSERVATIONS, ISM: molecules, Spectral imaging, Stars, techniques: imaging spectroscopy, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), CLOUD CORES, Substructure
Abstract

The understanding of the formation process of massive stars (>8 Msun) is limited, due to theoretical complications and observational challenges. We investigate the physical structure of the large-scale (~10^4-10^5 AU) molecular envelope of the high-mass protostar AFGL2591 using spectral imaging in the 330-373 GHz regime from the JCMT Spectral Legacy Survey. Out of ~160 spectral features, this paper uses the 35 that are spatially resolved. The observed spatial distributions of a selection of six species are compared with radiative transfer models based on a static spherically symmetric structure, a dynamic spherical structure, and a static flattened structure. The maps of CO and its isotopic variations exhibit elongated geometries on scales of ~100", and smaller scale substructure is found in maps of N2H+, o-H2CO, CS, SO2, CCH, and methanol lines. A velocity gradient is apparent in maps of all molecular lines presented here, except SO, SO2, and H2CO. We find two emission peaks in warm (Eup~200K) methanol separated by 12", indicative of a secondary heating source in the envelope. The spherical models are able to explain the distribution of emission for the optically thin H13CO+ and C34S, but not for the optically thick HCN, HCO+, and CS, nor for the optically thin C17O. The introduction of velocity structure mitigates the optical depth effects, but does not fully explain the observations, especially in the spectral dimension. A static flattened envelope viewed at a small inclination angle does slightly better. We conclude that a geometry of the envelope other than an isotropic static sphere is needed to circumvent line optical depth effects. We propose that this could be achieved in envelope models with an outflow cavity and/or inhomogeneous structure at scales smaller than ~10^4 AU. The picture of inhomogeneity is supported by observed substructure in at least six species., 17 pages; accepted for publication in A&A

Published
2011
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31. Water vapor toward starless cores: The Herschel view

Author

Doug Johnstone, Steven D. Doty, Per Bjerkeli, Pierre Encrenaz, Dominicus Kester, F. Daniel, Jes K. Jørgensen, F. F. S. van der Tak, M. Marseille, Asunción Fuente, Geoffrey A. Blake, Christophe Risacher, A. Megej, Hamid Javadi, Javier R. Goicoechea, Jonathan Braine, J. Santiago-Garcia, John C. Pearson, Fabrice Herpin, Dariusz C. Lis, Arnold O. Benz, T. A. van Kempen, David A. Neufeld, Carsten Dominik, P. Siegel, T. Jacq, Simon Bruderer, Gregory J. Herczeg, T. Giannini, Umut A. Yildiz, Berengere Parise, Michiel R. Hogerheijde, Friedrich Wyrowski, E. F. van Dishoeck, P. Saraceno, Th. de Graauw, W. Luinge, Eric Keto, Sylvain Bontemps, René Liseau, José Cernicharo, A. Di Giorgio, Milena Benedettini, C. Codella, Ruud Visser, Lars E. Kristensen, C. McCoey, B. Larsson, Rafael Bachiller, Russel Shipman, Brunella Nisini, Brian Jackson, Gary J. Melnick, Alain Baudry, S. F. Wampfler, M. Tafalla, Paola Caselli, W. M. Laauwen, Todd Gaier, M. Fich, Edwin A. Bergin, Yuri Aikawa, R. Plume, Laurent Pagani, Michael Olberg, Frank Helmich, Kapteyn Astronomical Institute, 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 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), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Harvard-Smithsonian Center for Astrophysics (CfA), Smithsonian Institution-Harvard University [Cambridge], INAF - Osservatorio Astronomico di Roma (OAR), 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 d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), 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), Centro de Investigaciones Biológicas (CSIC), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), SRON Netherlands Institute for Space Research (SRON), Onsala Space Observatory, Chalmers University of Technology [Göteborg], 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, ESO, European Southern Observatory (ESO), Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Radioastronomie (MPIFR), Low Energy Astrophysics (API, FNWI), École normale supérieure - Paris (ENS-PSL), Harvard University-Smithsonian Institution, 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 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), and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)

Subjects
Astronomy, FOS: Physical sciences, Astrophysics, INITIAL CONDITIONS, 7. Clean energy, ISM: clouds, OXYGEN, Gas phase, PRESTELLAR CORES, Radiative transfer, TEMPERATURE, Physics, stars: formation, DENSE INTERSTELLAR CLOUDS, Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], astrochemistry, Molecular cloud, Photodissociation, Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics - Astrophysics of Galaxies, MOLECULAR-IONS, molecular processes, L1544, 13. Climate action, Space and Planetary Science, radiative transfer, Astrophysics of Galaxies (astro-ph.GA), ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, PRE-STELLAR CORES, ABUNDANCE, line: formation, DEPLETION, Water vapor, Galaxy Astrophysics
Abstract

SWAS and Odin provided stringent upper limits on the gas phase water abundance of dark clouds (x(H2O) < 7x10^-9). We investigate the chemistry of water vapor in starless cores beyond the previous upper limits using the highly improved angular resolution and sensitivity of Herschel and measure the abundance of water vapor during evolutionary stages just preceding star formation. High spectral resolution observations of the fundamental ortho water (o-H2O) transition (557 GHz) were carried out with Herschel HIFI toward two starless cores: B68, a Bok globule, and L1544, a prestellar core embedded in the Taurus molecular cloud complex. The rms in the brightness temperature measured for the B68 and L1544 spectra is 2.0 and 2.2 mK, respectively, in a velocity bin of 0.59 km s^-1. The continuum level is 3.5+/-0.2 mK in B68 and 11.4+/-0.4 mK in L1544. No significant feature is detected in B68 and the 3 sigma upper limit is consistent with a column density of o-H2O N(o-H2O) < 2.5x10^13 cm^-2, or a fractional abundance x(o-H2O) < 1.3x10^-9, more than an order of magnitude lower than the SWAS upper limit on this source. The L1544 spectrum shows an absorption feature at a 5 sigma level from which we obtain the first value of the o-H2O column density ever measured in dark clouds: N(o-H2O) = (8+/-4)x10^12 cm^-2. The corresponding fractional abundance is x(o-H2O) ~ 5x10^-9 at radii > 7000 AU and ~2x10^-10 toward the center. The radiative transfer analysis shows that this is consistent with a x(o-H2O) profile peaking at ~10^-8, 0.1 pc away from the core center, where both freeze-out and photodissociation are negligible. Herschel has provided the first measurement of water vapor in dark regions. Prestellar cores such as L1544 (with their high central densities, strong continuum, and large envelopes) are very promising tools to finally shed light on the solid/vapor balance of water in molecular clouds., Accepted for publication in Astronomy and Astrophysics (HIFI first results issue)

Published
2010
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32. Two New Views of the Galactic Center

Author

D.T. Jaffe, R. Plume, and S. Pak

Subjects
010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, 0103 physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, 010303 astronomy & astrophysics, 01 natural sciences, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences
Abstract

The inner few hundred parsecs of the Galactic Center contains ∼10% of the molecular ISM in the Galaxy. The conditions in this gas are significantly different from those in molecular clouds elsewhere in the Galaxy. Typical temperatures, densities, and internal velocity dispersions are higher (Güesten 1989). There is also evidence for a large amount of molecular gas which is not bound to distinct clouds (Stark et al. 1989). High velocity bulk gas motions and velocity discontinuities open up the possibility of a role for powerful large-scale shocks in ISM excitation. The very different nature of the dense ISM in the inner Galaxy make it useful as a laboratory for physical effects in the interstellar medium and a proving ground for ideas about the interaction of gas and stars in the nuclei of other galaxies.

Published
1996
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33. Photometric Monitoring of Bright Be Stars. III. 1988-89 and 1992-95

Author

R. Plume, T. Rosebery, Matthew L. Lister, D. Yeung, Jason J. B. Harlow, K. A. W. Hayhoe, S. Thompson, I. I. Ivans, and John R. Percy

Subjects
Telescope, Physics, Stars, Space and Planetary Science, law, Astronomy, Astronomy and Astrophysics, Astrophysics, Light curve, law.invention
Abstract

We report long-term photometric (BV) observations of 23 bright, active Be stars made in 1988 and 1989 and 1992 and 1995 with the 0.4m telescope at the University of Toronto. Cumulative light curves, including observations made earlier at the University of Toronto, and with the Automatic Photometric Telescope Service in Arizona, are presented for several of the stars. Many of the stars show cyclic variations of up to 0.2 in V and B on time scales of a few years, as well as variations on time scales of about a day.

Published
1997
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35. ANALYSIS OF THE HERSCHEL/HEXOS SPECTRAL SURVEY TOWARD ORION SOUTH: A MASSIVE PROTOSTELLAR ENVELOPE WITH STRONG EXTERNAL IRRADIATION.

Author

K. Tahani, R. Plume, D. Johnstone, K. M. Menten, H. S. P. Müller, V. Ossenkopf-Okada, F. F. S. van der Tak, E. A. Bergin, V. Tolls, T. G. Phillips, D. C. Lis, E. Caux, S. Cabrit, L. Pagani, J. R. Goicoechea, P. F. Goldsmith, and J. C. Pearson

Subjects
*IRRADIATION, *HETERODYNE detection, *LOCAL thermodynamic equilibrium, *KINEMATICS, *MAGNETIC fields
Abstract

We present results from a comprehensive submillimeter spectral survey toward the source Orion South, based on data obtained with the Heterodyne Instrument for the Far-Infrared instrument on board the Herschel Space Observatory, covering the frequency range of 480 to 1900 GHz. We detect 685 spectral lines with signal-to-noise ratios (S/Ns) > 3σ, originating from 52 different molecular and atomic species. We model each of the detected species assuming conditions of Local Thermodynamic Equilibrium. This analysis provides an estimate of the physical conditions of Orion South (column density, temperature, source size, and VLSR). We find evidence for three different cloud components: a cool (Tex ∼ 20–40 K), spatially extended (>60″), and quiescent (ΔVFWHM ∼ 4 km s−1) component; a warmer (Tex ∼ 80–100 K), less spatially extended (∼30″), and dynamic (ΔVFWHM ∼ 8 km s−1) component, which is likely affected by embedded outflows; and a kinematically distinct region (Tex > 100 K; VLSR ∼ 8 km s−1), dominated by emission from species that trace ultraviolet irradiation, likely at the surface of the cloud. We find little evidence for the existence of a chemically distinct “hot-core” component, likely due to the small filling factor of the hot core or hot cores within the Herschel beam. We find that the chemical composition of the gas in the cooler, quiescent component of Orion South more closely resembles that of the quiescent ridge in Orion-KL. The gas in the warmer, dynamic component, however, more closely resembles that of the Compact Ridge and Plateau regions of Orion-KL, suggesting that higher temperatures and shocks also have an influence on the overall chemistry of Orion South. [ABSTRACT FROM AUTHOR]

Published
2016
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