Volume 521, October 2010
Herschel/HIFI: first science highlights
|Number of page(s)||6|
|Published online||01 October 2010|
Letter to the Editor
Herschel/HIFI observations towards G10.6-0.4 (W31C)
Onsala Space Observatory, Chalmers University of Technology, 43992 Onsala, Sweden e-mail: email@example.com
2 Centro de Astrobiologìa, CSIC-INTA, 28850 Madrid, Spain
3 Depts. of Physics, Ohio State Univ., USA
4 Depts. of Physics, Astronomy & Chemistry, Ohio State Univ., USA
5 LERMA, CNRS, Observatoire de Paris and ENS, France
6 California Institute of Technology, Cahill Center for Astronomy and Astrophysics 301-17, Pasadena, CA 91125, USA
7 Centre d'Étude Spatiale des Rayonnements (CESR), Université de Toulouse [UPS], 31062 Toulouse Cedex 9, France
8 CNRS/INSU, UMR 5187, 9 Avenue du Colonel Roche, 31028 Toulouse Cedex 4, France
9 JPL, California Institute of Technology, Pasadena, USA
10 Nicolaus Copernicus University, Toruń, Poland
11 Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
12 The Johns Hopkins University, Baltimore, MD 21218, USA
13 I. Physikalisches Institut, University of Cologne, Germany
14 Institut d'Astrophysique Spatiale (IAS), Orsay, France
15 Gemini telescope, Hilo, Hawaii, USA
16 LAM, OAMP, Université Aix-Marseille & CNRS, Marseille, France
17 Laboratoire d'Astrophysique de Grenoble, France
18 Institute of Physical Chemistry, PAS, Warsaw, Poland
19 MPI für Radioastronomie, Bonn, Germany
20 Dept. of Physics & Astronomy, University of Calgary, Canada
21 Nicolaus Copernicus Astronomical Center, Toruń, Poland
22 European Space Astronomy Centre, ESA, Madrid, Spain
23 Institut de Radioastronomie Millimétrique, IRAM, 300 rue de la Piscine, 38406 St. Martin d'Hères, France
24 Institute Université de Bordeaux, Laboratoire d'Astrophysique de Bordeaux, 33000 Bordeaux, France; and CNRS/INSU, UMR 5804, BP 89, 33271 Floirac Cedex, France
25 Infrared Processing and Analysis Center, California Institute of Technology, MS 100-22, Pasadena, CA 91125, USA
26 Observatorio Astronácional (IGN) and Atacama Large Millimeter/Submillimeter Array, Joint ALMA Office, Santiago, Chile
Accepted: 6 July 2010
The HIFI instrument on board the Herschel Space Observatory has been used to observe interstellar nitrogen hydrides along the sight-line towards G10.6-0.4 in order to improve our understanding of the interstellar chemistry of nitrogen. We report observations of absorption in NH N = 1 0, J = 2 1 and ortho-NH2 11,1 00,0. We also observed ortho-NH3 10 00, and 20 10, para-NH3 21 11, and searched unsuccessfully for NH+. All detections show emission and absorption associated directly with the hot-core source itself as well as absorption by foreground material over a wide range of velocities. All spectra show similar, non-saturated, absorption features, which we attribute to diffuse molecular gas. Total column densities over the velocity range 11-54 km s-1 are estimated. The similar profiles suggest fairly uniform abundances relative to hydrogen, approximately 6 × 10-9, 3 × 10-9, and 3 × 10-9 for NH, NH2, and NH3, respectively. These abundances are discussed with reference to models of gas-phase and surface chemistry.
Key words: astrochemistry / ISM: abundances / ISM: molecules / molecular processes / submillimetre: ISM / line: formation
Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.
Figures A.1 and A.2 (page 6) are only available in electronic form at http://www.aanda.org
© ESO, 2010
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