| Exploring the central molecular zone of the Galaxy using spectroscopy of H3+ and CO. | |
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MedLine Citation:
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PMID: 23028162 Owner: NLM Status: PubMed-not-MEDLINE |
Abstract/OtherAbstract:
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The central 400 parsecs of the Milky Way, a region known as the central molecular zone (CMZ), contains interstellar gas in a wide range of physical environments, from ultra-hot, rarified and highly ionized to warm, dense and molecular. The combination of infrared spectroscopy of H(3)(+) and CO is a powerful way to determine the basic properties of molecular interstellar gas, because the abundance ratio of H(3)(+) to CO in 'dense' clouds is quite different from that in 'diffuse' clouds. Moreover, the energy-level structure and the radiative properties of H(3)(+) combined with the unusually warm temperatures of molecular gas in the CMZ make H(3)(+) a unique probe of the physical conditions there. This paper describes how, using infrared absorption spectroscopy of H(3)(+) and CO, it has been discovered that a large fraction of the volume of the CMZ is filled with warm, diffuse and partially molecular gas moving at speeds of up to approximately 200 km s(-1) and that the mean cosmic ray ionization rate in the CMZ exceeds by roughly an order of magnitude values found in diffuse molecular clouds elsewhere in the Galaxy. |
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Authors:
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T R Geballe |
Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences Volume: 370 ISSN: 1364-503X ISO Abbreviation: Philos Trans A Math Phys Eng Sci Publication Date: 2012 Nov |
Date Detail:
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Created Date: 2012-10-02 Completed Date: 2012-11-13 Revised Date: 2013-04-24 |
Medline Journal Info:
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Nlm Unique ID: 101133385 Medline TA: Philos Trans A Math Phys Eng Sci Country: England |
Other Details:
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Languages: eng Pagination: 5151-61 Citation Subset: - |
Affiliation:
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Gemini Observatory, 670 N. A'ohoku Place, Hilo, HI 96720, USA. tgeballe@gemini.edu |
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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