Atomic Carbon Emission from Individual Molecular Clouds in M33
Abstract
We present observations of the 492 GHz [CI] emission for four individual giant molecular clouds in the Local Group galaxy M33 obtained with the James Clerk Maxwell Telescope. The average [CI] to CO J=1-0 integrated intensity ratio of 0.10+/-0.03 is similar to what is observed in Galactic molecular clouds but smaller than what is seen in starburst galaxies. Similarly, the column density ratio N(C)/N(CO) is similar to that observed in the Orion Bar, but smaller than values obtained for starburst galaxies. The [CI] line is found to be a more important coolant than the lowest three rotational transitions of CO for all the clouds in the sample. The [CI] luminosity does not appear to be enhanced significantly in two low-metallicity clouds, which may be due to the unusual ionization environment of the clouds.
Cite
@article{arxiv.astro-ph/9707158,
title = {Atomic Carbon Emission from Individual Molecular Clouds in M33},
author = {C. D. Wilson},
journal= {arXiv preprint arXiv:astro-ph/9707158},
year = {2009}
}
Comments
12 pages, aastex, 1 postscript figure; accepted for publication in ApJ Letters; also available at http://www.physics.mcmaster.ca/Wilson_Preprints/