| DOI | Resolve DOI: https://doi.org/10.1007/s10509-011-0662-5 |
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| Author | Search for: Bell, M. B.1; Search for: Avery, L. W.1; Search for: MacLeod, J. M.1; Search for: Vallée, J. P.1 |
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| Affiliation | - National Research Council of Canada. NRC Herzberg Institute of Astrophysics
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| Format | Text, Article |
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| ISSN | 0004-640X |
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| Subject | HII regions; ISM: abundances; radio lines: ISM |
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| Abstract | Sensitive spectral observations made in two frequency bands near 6.0 and 17.6 GHz are described for Orion and W51. Using frequency switching we were able to achieve a dynamic range in excess of 10,000 without fitting sinusoidal or polynomial baselines. This enabled us to detect lines as weak as TA ∼ 1 mK in these strong continuum sources. Hydrogen recombination lines with n as high as 25 have been detected in Orion. In the Orion data, where the lines are stronger, we have also detected a systematic shift in the line center frequencies proportional to linewidth that cannot be explained by normal optical depth effects. |
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| Publication date | 2011-06 |
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| In | |
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| Language | English |
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| Peer reviewed | Yes |
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| NPARC number | 19739593 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | d7a0976d-b03f-43ed-b62a-4ff83c6ee69a |
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| Record created | 2012-03-29 |
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| Record modified | 2020-04-21 |
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