Far-Infrared Excited Hydroxyl Lines from Orion KL Outflows
| Autor: | Serena Viti, Javier R. Goicoechea, M. R. Lerate, M. J. Barlow, José Cernicharo, Jeremy Yates, Fabien Daniel, Bruce Swinyard, Tanya L. Lim |
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| Přispěvatelé: | Henry, Florence, European Commission, Ministerio de Educación y Ciencia (España), 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), Departamento de Astrofisica Molecular e Infrarroja-Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Científica (CSIC), Rutherford Appleton Laboratory, University College of London [London] (UCL) |
| Jazyk: | angličtina |
| Rok vydání: | 2006 |
| Předmět: |
Physics
Infrared: ISM Spectrometer Mean kinetic temperature Infrared jets and outflows [ISM] ISM [Infrared] Astronomy and Astrophysics Spectral line ISM: molecules ISM: jets and outflows Far infrared Space and Planetary Science Excited state Radiative transfer Atomic physics [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ISM: individual (Orion KL) [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph] Excitation molecules [ISM] individual (Orion KL) [ISM] |
| Zdroj: | The Astrophysical journal letters The Astrophysical journal letters, 2006, 641, pp.L49-L52 Digital.CSIC. Repositorio Institucional del CSIC instname BASE-Bielefeld Academic Search Engine |
| ISSN: | 2005-5153 2041-8205 2041-8213 |
| Popis: | 4 pags., 3 figs. As part of the first far-IR line survey toward Orion KL, we present the detection of seven new rotationally excited OH A-doublets (at ∼48, ∼65, ∼71, ∼79, ∼98, and ∼115 μm). Observations were performed with the Long Wavelength Spectrometer Fabry-Pérot on board the Infrared Space Observatory. In total, more than 20 resolved OH rotational lines, with upper energy levels up to ∼620 K, have been detected at angular and velocity resolutions of ∼80> and ∼33 km s-1, respectively. The OH line profiles show a complex behavior evolving from pure absorption, P Cygni type, to pure emission. We also present a large-scale, 6' declination raster in the OH 2II3/2 J = 5/2+-3/2- and 2II3/2 J = 7/2-5/2+ lines (at 119.441 and 84.597 μm) revealing a decrease of excitation outside the core of the cloud. From the observed profiles, mean intrinsic line widths, and velocity offsets between emission and absorption line peaks, we conclude that most of the excited OH arises from Orion outflow(s), that is, the >plateau> spectral component. We determine an averaged OH abundance relative to H 2 of x(OH) = (0.51.0) × 10-6, a kinetic temperature of ≥100 K, and a density of n(H2) ≲ 5 × 105 cm-3. Even with these conditions, the OH excitation is heavily coupled with the strong dust continuum emission from the inner >hot core> regions and from the expanding flow itself. © 2006. The American Astronomical Society. All rights reserved. J. R. G. was supported by a Marie Curie Intra-European Individual Fellowship within the Sixth European Community Framework Programme, contract MEIF-CT-2005-515340. We acknowledge the Spanish DGES and PNIE grants ESP 2001-4516 and AYA 2003-2785. |
| Databáze: | OpenAIRE |
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