The Herschel M 33 extended survey (HerM33es): PACS spectroscopy of the star-forming region BCLMP 302
Creators
- Mookerjea, B.1
- Kramer, C.2
- Buchbender, C.2
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Boquien, M.3
- Verley, S.4
- Relaño, M.4
- Quintana-Lacaci, G.2
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Aalto, S.5
- Braine, J.6
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Calzetti, D.3
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Combes, F.7
- García-Burillo, S.8
- Gratier, P.9
- Henkel, C.9
- Israel, F.10
- Lord, S.11
- Nikola, T.12
- Röllig, M.13
- Stacey, G.12
- Tabatabaei, F. S.9
- van der Tak, F.14
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van der Werf, P.10, 15
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1.
Tata Institute of Fundamental Research
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2.
Instituto de Radioastronomía Milimétrica
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3.
University of Massachusetts Amherst
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4.
University of Granada
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5.
Chalmers University of Technology
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6.
Observatoire Aquitain des Sciences de l'Univers
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7.
Paris Observatory
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8.
Spanish National Observatory
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9.
Max Planck Institute for Radio Astronomy
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10.
Leiden University
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11.
California Institute of Technology
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12.
Cornell University
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13.
University of Cologne
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14.
Netherlands Institute for Space Research
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15.
University of Edinburgh
Abstract
Context. The emission line of [C _(II)] at 158 μm is one of the strongest cooling lines of the interstellar medium (ISM) in galaxies. Aims. Distinguishing the relative contributions of the different ISM phases to [C _(II)] emission is a major objective of the HerM33es program, a Herschel key project to study the ISM in the nearby spiral galaxy M 33. Methods. Using PACS, we have mapped the emission of [C _(II)] 158 μm, [O _I] 63 μm, and other FIR lines in a 2'×2′ region of the northern spiral arm of M 33, centered on the H_(II) region BCLMP 302. At the peak of Hα emission, we observed in addition a velocity-resolved [C _(II)] spectrum using HIFI. We use scatterplots to compare these data with PACS 160 μm continuum maps, and with maps of CO and H_I data, at a common resolution of 12″ or 50 pc. Maps of Hα and 24 μm emission observed with Spitzer are used to estimate the SFR. We created maps of the [C _(II)] and [O_ I] 63 μm emission and detected [N _(II)] 122 μm and [N _(III)] 57 μm at individual positions. Results. The [C _(II)] line observed with HIFI is significantly broader than that of CO, and slightly blue-shifted. In addition, there is little spatial correlation between [C _(II)] observed with PACS and CO over the mapped region. There is even less spatial correlation between [C _(II)] and the atomic gas traced by H _I. Detailed comparison of the observed intensities towards the H _(II) region with models of photo-ionization and photon-dominated regions, confirms that a significant fraction, 20–30%, of the observed [C _(II)] emission stems from the ionized gas and not from the molecular cloud. The gas heating efficiency, using the ratio of [C _(II)] to the TIR as a proxy, varies between 0.07 and 1.5%, with the largest variations found outside the H _(II) region.
Additional Information
© 2011 ESO. Received 6 January 2011. Accepted 21 June 2011. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Attached Files
Published - Mookerjea2011p15919Astron_Astrophys.pdf
Erratum - Mookerjea2012p17742Astron_Astrophys.pdf
Files
Mookerjea2011p15919Astron_Astrophys.pdf
Additional details
Identifiers
- Eprint ID
- 25465
- Resolver ID
- CaltechAUTHORS:20110928-101108669
Dates
- Created
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2011-09-29Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field