AST/RO super(13)CO(J = 2 arrow right 1) and super(12)CO(J = 4 arrow right 3) Mapping of Southern Spitzer c2d Small Clouds and Cores

• Published in: The Astrophysical journal. Supplement series Vol. 171; no. 2; pp. 478 - 492
• Main Authors: Loehr, A, Bourke, T L, Lane, A P, Myers, P C, Parshley, S C, Stark, A A, Tothill, NFH
• Format: Journal Article
• Language: English
• Published: 01.08.2007
• ISSN: 0067-0049
• DOI: 10.1086/517608

Forty molecular cloud cores in the southern hemisphere from the initial Spitzer Space Telescope Cores-to-Disks (c2d) Legacy program source list have been surveyed in super(13)CO(2 arrow right 1), super(12)CO(4 arrow right 3), and super(12)CO(7 arrow right 6) with the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO). The cores, 10 of which contain embedded sources, are located mostly in the Vela, Ophiuchus, Lupus, Chamaeleon, Musca, and Scorpius complexes. super(12)CO(7 arrow right 6) emission was undetected in all 40 clouds. We present data of 40 sources in super(13)CO(2 arrow right 1) and super(12)CO(4 arrow right 3), significant upper limits of super(12)CO(7 arrow right 6), as well as a statistical analysis of the observed properties of the clouds. We find the typical super(13)CO(2 arrow right 1) line width to be 2.0 km s super(-1) for cores with embedded stars and 1.8 km s super(-1) for all others. The typical super(12)CO(4 arrow right 3) line width is 2.6-3.7 km s super(-1) for cores with known embedded sources, and 1.6-2.3 km s super(-1) for all others. The average super(13)CO column density derived from the line intensities was found to be 1.9 x 10 super(15) cm super(-2) for cores with embedded stars and 1.5 x 10 super(15) cm super(-2) for all others. The average kinetic temperature in the molecular cores, determined through a large velocity gradient analysis of a set of nine cores, has an average lower limit of 16 K and an average upper limit of 26 K. The average molecular hydrogen density has an average lower limit of 10 super(2.9) cm super(-3) and an average upper limit of 10 super(3.3) cm super(-3) for all cores. For a different subset of nine cores, we have derived masses. They range from 4 to 255 M [unk]. Overall, our c2d sample of southern molecular cores has a range of properties (line width, column density, size, mass, embedded stars) similar to those of past studies.