dc.contributor.author | Anderson, L. D. | |
dc.contributor.author | Bania, T. M. | |
dc.contributor.author | Jackson, James M. | |
dc.contributor.author | Clemens, D. P. | |
dc.contributor.author | Heyer, Mark | |
dc.contributor.author | Simon, R. | |
dc.contributor.author | Rathborne, J. M. | |
dc.contributor.author | Shah, Ronak | |
dc.date.accessioned | 2015-03-12T20:18:27Z | |
dc.date.available | 2015-03-12T20:18:27Z | |
dc.date.issued | 2009-03 | |
dc.date.submitted | 2008-08 | |
dc.identifier.issn | 0067-0049 | |
dc.identifier.issn | 1538-4365 | |
dc.identifier.uri | http://hdl.handle.net/1721.1/96001 | |
dc.description.abstract | We derive the molecular properties for a sample of 301 Galactic H II regions including 123 ultra compact (UC), 105 compact, and 73 diffuse nebulae. We analyze all sources within the BU-FCRAO Galactic Ring Survey (GRS) of [superscript 13]CO emission known to be H II regions based upon the presence of radio continuum and cm-wavelength radio recombination line emission. Unlike all previous large area coverage [superscript 13]CO surveys, the GRS is fully sampled in angle and yet covers ~75 deg[superscript 2] of the Inner Galaxy. The angular resolution of the GRS (46'') allows us to associate molecular gas with H II regions without ambiguity and to investigate the physical properties of this molecular gas. We find clear CO/H II morphological associations in position and velocity for ~80% of the nebular sample. Compact H II region molecular gas clouds are on average larger than UC clouds: 2'2 compared to 1'7. Compact and UC H II regions have very similar molecular properties, with ~5 K line intensities and ~4 km s[superscript –1] line widths. The diffuse H II region molecular gas has lower line intensities, ~3 K, and smaller line widths, ~3.5 km s[superscript –1]. These latter characteristics are similar to those found for quiescent molecular clouds in the GRS. Our sample nebulae thus show evidence for an evolutionary sequence wherein small, dense molecular gas clumps associated with UC H II regions grow into older compact nebulae and finally fragment and dissipate into large, diffuse nebulae. | en_US |
dc.description.sponsorship | National Science Foundation (U.S.) (Grant AST-9800334) | en_US |
dc.description.sponsorship | National Science Foundation (U.S.) (Grant AST-0098562) | en_US |
dc.description.sponsorship | National Science Foundation (U.S.) (Grant AST-0100793) | en_US |
dc.description.sponsorship | National Science Foundation (U.S.) (Associated Universities, Inc. Cooperative Research Agreement) | en_US |
dc.description.sponsorship | National Radio Astronomy Observatory (U.S.) | en_US |
dc.language.iso | en_US | |
dc.publisher | IOP Publishing | en_US |
dc.relation.isversionof | http://dx.doi.org/10.1088/0067-0049/181/1/255 | en_US |
dc.rights | Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. | en_US |
dc.source | American Astronomical Society | en_US |
dc.title | THE MOLECULAR PROPERTIES OF GALACTIC H II REGIONS | en_US |
dc.type | Article | en_US |
dc.identifier.citation | Anderson, L. D., T. M. Bania, J. M. Jackson, D. P. Clemens, M. Heyer, R. Simon, R. Y. Shah, and J. M. Rathborne. “THE MOLECULAR PROPERTIES OF GALACTIC H II REGIONS.” The Astrophysical Journal Supplement Series 181, no. 1 (March 1, 2009): 255–271. © 2009 The American Astronomical Society | en_US |
dc.contributor.department | Lincoln Laboratory | en_US |
dc.contributor.mitauthor | Shah, Ronak | en_US |
dc.relation.journal | Astrophysical Journal. Supplement Series | en_US |
dc.eprint.version | Final published version | en_US |
dc.type.uri | http://purl.org/eprint/type/JournalArticle | en_US |
eprint.status | http://purl.org/eprint/status/PeerReviewed | en_US |
dspace.orderedauthors | Anderson, L. D.; Bania, T. M.; Jackson, J. M.; Clemens, D. P.; Heyer, M.; Simon, R.; Shah, R. Y.; Rathborne, J. M. | en_US |
mit.license | PUBLISHER_POLICY | en_US |
mit.metadata.status | Complete | |