AAS 195th Meeting, January 2000
Session 73. ISM: Molecular Gas
Display, Friday, January 14, 2000, 9:20am-6:30pm, Grand Hall

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[73.01] Using Rotational Transitions of Methyl Cyanide (CH_3CN) as a Temperature Indicator in Molecular Clouds

A. C. Schwortz (Alfred University), J. G. Mangum (National Radio Astronomy Observatory, Tucson)

Traditionally, the inversion transitions of ammonia (NH_3) have been used as a primary temperature indicator. However, the physical model typically used for this method assumes that only three energy levels are populated. This model breaks down when the temperature becomes high enough, about 50K. Previous investigations to determine the temperatures of the cores of molecular clouds found them to be at about 70-150K. As these temperatures are beyond the range of accuracy of the inversion transition method, these numbers have great inherrant inaccuracies. We have investigated the utility of the CH_3CN molecule as a temperature monitor which retains its accuracy at higher temperatures. Using CH_3CN rotational transitions and two separate methods of analyzing the resultant data, we have obtained good temperature and column density figures for some 24 molecular cloud cores within our galaxy.

This project was partially supported by NRAO and the NSF REU program.


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The author(s) of this abstract have provided an email address for comments about the abstract: schworac@hotmail.com

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