Letter to the Editor
Physical properties of the Sh2-104 H II region as seen by Herschel*
Laboratoire d'Astrophysique de Marseille (UMR 6110 CNRS and
Université de Provence), 38 rue F. Joliot-Curie, 13388 Marseille
Cedex 13, France e-mail: email@example.com
2 Institute for Space Imaging Science, University of Lethbridge, Lethbridge, Canada
3 Space Science Department, Rutherford Appleton Laboratory, Chilton, UK
4 Institut d'Astrophysique Spatiale, CNRS/Université Paris-Sud 11, 91405 Orsay, France
5 CEA, Laboratoire AIM, Irfu/SAp, Orme des Merisiers, 91191 Gif-sur-Yvette, France
6 CNRS/INSU, Laboratoire d'Astrophysique de Bordeaux, UMR 5804, BP 89, 33271 Floirac Cedex, France
7 Department of Physics and Astronomy, Cardiff University, UK
8 Infrared Processing & Analysis Center, California Institute of Technology, Mail Code 100-22, 770 South Wilson Av, Pasadena, CA 91125, USA
9 Universié de Toulouse; UPS; CESR; and CNRS; UMR5187, 9 avenue du colonel Roche, 31028 Toulouse Cedex 4, France
10 Canadian Institute for Theoretical Astrophysics, Toronto, Ontario, M5S 3H8, Canada
11 University of California, Radio Astronomy Laboratory, Berkeley, 601 Campbell Hall, US Berkeley CA 94720-3411, USA
12 Institut de Radioastronomie Millimétrique (IRAM), 300 rue de la Piscine, 38406 Saint-Martin-d'Hères, France
13 National Astronomical Observatories, PR China
14 Blue Sky Spectrosocpy Inc, Lethbridge, Canada
15 Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
16 Istituto di Fisica dello Spazio Interplanetario, INAF, via del Fosso del Cavaliere 100, 00133 Roma, Italy
17 NASA – Goddard SFC, USA
18 Laboratoire des Signaux et Systèmes (CNRS & Supélec & Université Paris-Sud 11), Moulon, 91192 Gif-sur-Yvette, France
19 Centre for Astrophysics and Planetary Science, School of Physical Sciences, University of Kent, Kent, UK
20 Department of Physics & Astronomy, The Open University, Milton Keynes MK7 6AA, UK
Accepted: 7 May 2010
Context. Sh2-104 is a Galactic H ii region with a bubble morphology, detected at optical and radio wavelengths. It is considered the first observational confirmation of the collect-and-collapse model of triggered star-formation.
Aims. We aim to analyze the dust and gas properties of the Sh2-104 region to better constrain its effect on local future generations of stars. In addition, we investigate the relationship between the dust emissivity index β and the dust temperature, Tdust.
Methods. Using Herschel PACS and SPIRE images at 100, 160, 250, 350 and 500 μm we determine Tdust and β throughout Sh2-104, fitting the spectral energy distributions (SEDs) obtained from aperture photometry. With the SPIRE Fourier-transform spectrometer (FTS) we obtained spectra at different positions in the Sh2-104 region. We detect J-ladders of 12CO and 13CO, with which we derive the gas temperature and column density. We also detect proxies of ionizing flux as the [Nii] 3P1-3P0 and [Ci] 3P2–3P1 transitions.
Results. We find an average value of β ~ 1.5 throughout Sh2-104, as well as a Tdust difference between the photodissociation region (PDR, ~25 K) and the interior (~40 K) of the bubble. We recover the anti-correlation between β and dust temperature reported numerous times in the literature. The relative isotopologue abundances of CO appear to be enhanced above the standard ISM values, but the obtained value is very preliminary and is still affected by large uncertainties.
Key words: stars: formation / ISM: bubbles / H ii regions / dust, extinction / infrared: ISM / ISM: individual objects: Sh2-104
© ESO, 2010