Astron. Astrophys. 354, 1036-1040 (2000)

Probing the properties of methyl cyanide sources

S.V. Kalenskii ¹, V.G. Promislov ¹, A.V. AlakozA. Winnberg ^1,3,2 and L.E.B. Johansson <sup>2

1</sup> Astro Space Center of Lebedev Physical Institute, Profsoyuznaya 84/32, 117810 Moscow, Russia (kalensky@dpc.asc.rssi.ru; vitaly@diogen.asc.rssi.ru; alakoz@dpc.asc.rssi.ru)
² Onsala Space Observatory, 439 92 Onsala, Sweden (anders@oso.chalmers.se; leb@oso.chalmers.se)
³ Moscow State University, Physical Faculty, Astronomical Department, Universitetskii pr. 13, 119899 Moscow, Russia

Received 18 September 1998 / Accepted 22 December 1999

Abstract

A survey of 27 galactic star-forming regions in the and CH₃CN lines at 110 and 92 GHz, respectively, was made. Twenty-five sources were detected at 110 GHz and nineteen at 92 GHz. The strongest CH₃CN emission arise in hot cores in the regions of massive star formation. CH₃CN abundance in these objects is increased up to or larger. Weaker CH₃CN lines were found in a number of sources. They may arise in warm (30-50 K) clouds.

Key words: ISM: clouds ISM: molecules ISM: abundances radio lines: ISM

Send offprint requests to: A. Winnberg

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations
• 3. Results
• 4. Statistical equilibrium calculations
• 5. Discussion and conclusions
• Acknowledgements
• References

© European Southern Observatory (ESO) 2000

Online publication: February 25, 2000
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