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1. Disruption of the Orion molecular core 1 by wind from the massive star θ

Author

C, Pabst, R, Higgins, J R, Goicoechea, D, Teyssier, O, Berne, E, Chambers, M, Wolfire, S T, Suri, R, Guesten, J, Stutzki, U U, Graf, C, Risacher, and A G G M, Tielens

Subjects
Article
Abstract

Massive stars inject mechanical and radiative energy into the surrounding environment, which stirs it up, heats the gas, produces cloud and intercloud phases in the interstellar medium, and disrupts molecular clouds (the birth sites of new stars

Published
2018

2. 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

3. 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

4. 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

5. 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

6. 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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7. A 275370 GHz Receiver Employing Novel Probe Structure.

Author

C. Risacher, V. Belitsky, V. Vassilev, I. Lapkin, and A. Pavolotsky

Subjects
CRYOELECTRONICS, WAVEGUIDES, OPTICAL instruments, ASTRONOMICAL instruments
Abstract

Abstract We present the results of the development of a 275370 GHz, fixed-tuned double sideband (DSB) receiver based on superconductor-insulator-superconductor (SIS) junction mixer. The mixer block uses a full height rectangular waveguide and employs a novel radial-like probe structure with integrated bias-T. The measured uncorrected receiver noise temperature is 3050 K corresponding to about 23 quantum noise across the full frequency band with an IF from 3.8 to 7.6 GHz. The mixer is to be used on the Atacama Pathfinder EXperiment (APEX) submillimeter telescope in Chile. [ABSTRACT FROM AUTHOR]

Published
2005

8. Astrophysical detection of the helium hydride ion HeH .

Author

Güsten R, Wiesemeyer H, Neufeld D, Menten KM, Graf UU, Jacobs K, Klein B, Ricken O, Risacher C, and Stutzki J

Abstract

During the dawn of chemistry 1,2 , when the temperature of the young Universe had fallen below some 4,000 kelvin, the ions of the light elements produced in Big Bang nucleosynthesis recombined in reverse order of their ionization potential. With their higher ionization potentials, the helium ions He 2+ and He + were the first to combine with free electrons, forming the first neutral atoms; the recombination of hydrogen followed. In this metal-free and low-density environment, neutral helium atoms formed the Universe's first molecular bond in the helium hydride ion HeH + through radiative association with protons. As recombination progressed, the destruction of HeH + created a path to the formation of molecular hydrogen. Despite its unquestioned importance in the evolution of the early Universe, the HeH + ion has so far eluded unequivocal detection in interstellar space. In the laboratory the ion was discovered 3 as long ago as 1925, but only in the late 1970s was the possibility that HeH + might exist in local astrophysical plasmas discussed 4-7 . In particular, the conditions in planetary nebulae were shown to be suitable for producing potentially detectable column densities of HeH + . Here we report observations, based on advances in terahertz spectroscopy 8,9 and a high-altitude observatory 10 , of the rotational ground-state transition of HeH + at a wavelength of 149.1 micrometres in the planetary nebula NGC 7027. This confirmation of the existence of HeH + in nearby interstellar space constrains our understanding of the chemical networks that control the formation of this molecular ion, in particular the rates of radiative association and dissociative recombination.

Published
2019
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9. Disruption of the Orion molecular core 1 by wind from the massive star θ 1 Orionis C.

Author

Pabst C, Higgins R, Goicoechea JR, Teyssier D, Berne O, Chambers E, Wolfire M, Suri ST, Guesten R, Stutzki J, Graf UU, Risacher C, and Tielens AGGM

Abstract

Massive stars inject mechanical and radiative energy into the surrounding environment, which stirs it up, heats the gas, produces cloud and intercloud phases in the interstellar medium, and disrupts molecular clouds (the birth sites of new stars 1,2 ). Stellar winds, supernova explosions and ionization by ultraviolet photons control the lifetimes of molecular clouds 3-7 . Theoretical studies predict that momentum injection by radiation should dominate that by stellar winds 8 , but this has been difficult to assess observationally. Velocity-resolved large-scale images in the fine-structure line of ionized carbon ([C II]) provide an observational diagnostic for the radiative energy input and the dynamics of the interstellar medium around massive stars. Here we report observations of a one-square-degree region (about 7 parsecs in diameter) of Orion molecular core 1-the region nearest to Earth that exhibits massive-star formation-at a resolution of 16 arcseconds (0.03 parsecs) in the [C II] line at 1.9 terahertz (158 micrometres). The results reveal that the stellar wind originating from the massive star θ 1 Orionis C has swept up the surrounding material to create a 'bubble' roughly four parsecs in diameter with a 2,600-solar-mass shell, which is expanding at 13 kilometres per second. This finding demonstrates that the mechanical energy from the stellar wind is converted very efficiently into kinetic energy of the shell and causes more disruption of the Orion molecular core 1 than do photo-ionization and evaporation or future supernova explosions.

Published
2019
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10. [Cii] emission from L1630 in the Orion B molecular cloud.

Author

Pabst CHM, Goicoechea JR, Teyssier D, Berné O, Ochsendorf BB, Wolfire MG, Higgins RD, Riquelme D, Risacher C, Pety J, Le Petit F, Roueff E, Bron E, and Tielens AGGM

Abstract

Context: L1630 in the Orion B molecular cloud, which includes the iconic Horsehead Nebula, illuminated by the star system σ Ori, is an example of a photodissociation region (PDR). In PDRs, stellar radiation impinges on the surface of dense material, often a molecular cloud, thereby inducing a complex network of chemical reactions and physical processes., Aims: Observations toward L1630 allow us to study the interplay between stellar radiation and a molecular cloud under relatively benign conditions, that is, intermediate densities and an intermediate UV radiation field. Contrary to the well-studied Orion Molecular Cloud 1 (OMC1), which hosts much harsher conditions, L1630 has little star formation. Our goal is to relate the [Cii] fine-structure line emission to the physical conditions predominant in L1630 and compare it to studies of OMC1., Methods: The [Cii] 158 μ m line emission of L1630 around the Horsehead Nebula, an area of 12' × 17', was observed using the upgraded German Receiver for Astronomy at Terahertz Frequencies (upGREAT) onboard the Stratospheric Observatory for Infrared Astronomy (SOFIA)., Results: Of the [Cii] emission from the mapped area 95%, 13 L ⊙ , originates from the molecular cloud; the adjacent Hii region contributes only 5%, that is, 1 L ⊙ . From comparison with other data (CO(1-0)-line emission, far-infrared (FIR) continuum studies, emission from polycyclic aromatic hydrocarbons (PAHs)), we infer a gas density of the molecular cloud of n H ∼ 3 · 10 3 cm -3 , with surface layers, including the Horsehead Nebula, having a density of up to n H ∼ 4 · 10 4 cm -3 . The temperature of the surface gas is T ∼ 100 K. The average [Cii] cooling efficiency within the molecular cloud is 1.3 · 10 -2 . The fraction of the mass of the molecular cloud within the studied area that is traced by [Cii] is only 8%. Our PDR models are able to reproduce the FIR-[Cii] correlations and also the CO(1-0)-[Cii] correlations. Finally, we compare our results on the heating efficiency of the gas with theoretical studies of photoelectric heating by PAHs, clusters of PAHs, and very small grains, and find the heating efficiency to be lower than theoretically predicted, a continuation of the trend set by other observations., Conclusions: In L1630 only a small fraction of the gas mass is traced by [Cii]. Most of the [Cii] emission in the mapped area stems from PDR surfaces. The layered edge-on structure of the molecular cloud and limitations in spatial resolution put constraints on our ability to relate different tracers to each other and to the physical conditions. From our study, we conclude that the relation between [Cii] emission and physical conditions is likely to be more complicated than often assumed. The theoretical heating efficiency is higher than the one we calculate from the observed [Cii] emission in the L1630 molecular cloud.

Published
2017
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11. Concentrations of halogenated natural products versus PCB 153 in bivalves from the North and Baltic Seas.

Author

Hauler C, Rimkus G, Risacher C, Knölker HJ, and Vetter W

Subjects
Animals, Baltic States, Polychlorinated Biphenyls standards, Water Pollutants, Chemical standards, Bivalvia metabolism, Environmental Monitoring, Polychlorinated Biphenyls metabolism, Water Pollutants, Chemical metabolism
Abstract

Different halogenated natural products (HNPs) have been reported to occur in marine wildlife, particularly from regions with comparably little contamination with anthropogenic pollutants. The North Sea and the Baltic Sea have been known as a marine site heavily polluted with organohalogen compounds, and especially with polychlorinated biphenyls (PCBs). In this study we wished to determine the current abundance of HNPs in comparison with 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153), i.e. the major PCB congener in marine biota. For this purpose, forty blue mussels (Mytilus edulis) and oysters (Crassostrea gigas) from seven sites were analyzed on HNPs and PCB 153. Most of the samples contained HNPs in the form of polyhalogenated 1'-methyl-1,2'-bipyrroles (PMBPs including Q1) and the mixed halogenated compound MHC-1. In addition we determined several polyhalogenated 1,1'-dimethyl-2,2'-bipyrroles (PDBPs), 2,3,4,5-tetrabromo-N-methylpyrrole and several novel homologs, as well as polybrominated N-methylindoles. The occurrence of these HNP groups were considerably different in the samples from different regions with varying sum concentrations up to 1930 μg/kg lipids in blue mussels from Heligoland (North Sea) and much lower concentrations in samples from the Baltic Sea (up to 13 μg/kg lipids). The concentrations of HNPs varied by two orders of magnitude, compared to a factor of 10 for PCB 153, suggesting that HNPs are more spatially (and perhaps temporally) variant than POPs. In the North Sea region Heligoland, HNPs were more abundant than PCB 153., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Published
2014
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