Extended [C I] and ^{13}CO(5-4) Emission in M17SW
Abstract
We mapped a 13 by 22 pc region in emission from 492 GHz [C I] and, for the first time, 551 GHz ^{13}CO(5-4) in the giant molecular cloud M17SW, using the Submillimeter Wave Astronomy Satellite. The morphologies of the [C I] and ^{13}CO emission are strikingly similar. The extent and intensity of the [C I] and ^{13}CO(5-4) emission is explained as arising from photodissociation regions on the surfaces of embedded molecular clumps. Modeling of the ^{13}CO(5-4) emission in comparison to ^{13}CO(1-0) indicates a temperature gradient across the cloud, peaking to at least 63 K near the M17 ionization front and decreasing to at least 20 K at the western edge of the cloud. We see no correlation between gas density and column density. The beam-averaged column density of C I in the core is 1x10^{18} cm^-2, and the mean column density ratio N(C I)/N(CO) is about 0.4. The variations of N(C I)/N(CO) with position in M17SW indicate a similar clump size distribution throughout the cloud.
Keywords
Cite
@article{arxiv.astro-ph/0010394,
title = {Extended [C I] and ^{13}CO(5-4) Emission in M17SW},
author = {J. E. Howe and M. L. N. Ashby and E. A. Bergin and G. Chin and N. R. Erickson and P. F. Goldsmith and M. Harwit and D. J. Hollenbach and M. J. Kaufman and S. C. Kleiner and D. G. Koch and D. A. Neufeld and B. M. Patten and R. Plume and R. Schieder and R. L. Snell and J. R. Stauffer and V. Tolls and Z. Wang and G. Winnewisser and Y. F. Zhang and G. J. Melnick},
journal= {arXiv preprint arXiv:astro-ph/0010394},
year = {2009}
}
Comments
5 pages, 3 Postscript figures, uses aastex.cls, emulateapj5.sty (included), and apjfonts.sty (included)