The M(17)SW molecular source - Internally or externally heated?

Chown, M. P.; Beckman, J. E.; Cronin, N. J.; White, G. J.
Bibliographical reference

IN: Submillimetre wave astronomy (A84-29251 12-89). Cambridge and New York, Cambridge University Press, 1982, p. 159-165.

Advertised on:
0
1982
Number of authors
4
IAC number of authors
0
Citations
2
Refereed citations
2
Description
From a measurement of the J = 3 - 2 rotational emission line of hydrogen isocyanide, and a literature value for that J = 1 - 0 line (Snell, 1979), the excitation parameters for HNC in the direction of the molecular peak as determined by CO were derived. Kinetic temperatures for the optically thick CO and (C-13)O transitions are about 50 K, while that pertaining to HNC line formation is between 20 K and 5 K. The inference that the central temperature of the cloud is lower than that of its surface supports models in which the cloud is heated not from within, but by the O-B association to the northwest.