Herschel-PACS spectroscopy of the intermediate mass protostar NGC7129 FIRS 2

M. Fich , D. Johnstone , T. A. van Kempen , C. Mccoey , A. Fuente , P. Caselli (1) , L. E. Kristensen , R. Plume , J. Cernicharo (2) , G. J. Herczeg , E. F. van Dishoeck , S. Wampfler , P. Gaufre , J. J. Gill , H. Javadi , M. Justen , W. Laauwen , W. Luinge , V. Ossenkopf , Justin Pearson , R. Bachiller , Alain Baudry (3, 4, 5, 6) , M. Benedettini , E. Bergin , A. O. Benz , P. Bjerkeli , G. Blake (7) , Sylvain Bontemps (3, 4, 5, 6) , J. Braine (3, 4, 5, 6) , S. Bruderer , C. Codella , F. Daniel , A. M. Di Giorgio , C. Dominik (8) , S. D. Doty , P. Encrenaz (9) , T. Giannini , J. R. Goicoechea (9) , Th. de Graauw , F. Helmich , Fabrice Herpin (3, 4, 5, 6) , M. R. Hogerheijde , T. Jacq (3, 4, 5, 6) , J. K. Jorgensen , B. Larsson , D. Lis , R. Liseau , M. Marseille (3, 4, 5, 6, 10) , G. Melnick , B. Nisini (11) , M. Olberg (12) , B. Parise (13) , C. Risacher (14) , J. Santiago , P. Saraceno (15) , R. Shipman , M. Tafalla , F. van Der Tak , R. Visser , F. Wyrowski (16) , U. A. Yildiz

1 OAA - INAF - Osservatorio Astrofisico di Arcetri
2 CSIC - Centro de Investigaciones Biológicas
3 OASU - Observatoire aquitain des sciences de l'univers
4 LAB - Laboratoire d'Astrophysique de Bordeaux [Pessac]
5 UB - Université Sciences et Technologies - Bordeaux 1
6 L3AB - Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux
7 LOCIE - LabOratoire proCédés énergIe bâtimEnt
8 AI PANNEKOEK - Astronomical Institute Anton Pannekoek
9 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique
10 SRON - SRON Netherlands Institute for Space Research
11 OAR - INAF - Osservatorio Astronomico di Roma
12 Onsala Space Observatory
13 CESR - Centre d'étude spatiale des rayonnements
14 ESO
15 IFSI - Istituto di Fisica dello Spazio Interplanetario
16 MPIFR - Max-Planck-Institut für Radioastronomie

Aims: We present preliminary results of the first Herschel spectroscopic observations of NGC7129 FIRS2, an intermediate mass star-forming region. We attempt to interpret the observations in the framework of an in-falling spherical envelope. Methods: The PACS instrument was used in line spectroscopy mode (R=1000-5000) with 15 spectral bands between 63 and 185 microns. This provided good detections of 26 spectral lines seen in emission, including lines of H2O, CO, OH, O I, and C II. Results: Most of the detected lines, particularly those of H2O and CO, are substantially stronger than predicted by the spherical envelope models, typically by several orders of magnitude. In this paper we focus on what can be learned from the detected CO emission lines. Conclusions: It is unlikely that the much stronger than expected line emission arises in the (spherical) envelope of the YSO. The region hot enough to produce such high excitation lines within such an envelope is too small to produce the amount of emission observed. Virtually all of this high excitation emission must arise in structures such as as along the walls of the outflow cavity with the emission produced by a combination of UV photon heating and/or non-dissociative shocks.

Mots clés: Astrophysics; Galaxy Astrophysics

Domaines: Astrophysique stellaire et solaire [astro-ph.SR]; Astrophysique stellaire et solaire [astro-ph.SR]

M. Fich, D. Johnstone, T. A. van Kempen, C. Mccoey, A. Fuente, et al.. Herschel-PACS spectroscopy of the intermediate mass protostar NGC7129 FIRS 2. Astronomy and Astrophysics - A&A, 2010, 518, pp.L86. ⟨10.1051/0004-6361/201014672⟩. ⟨hal-00495808⟩