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We present an in-depth case study of three molecular clouds associated with the walls of the Galactic supershells GSH 287+04-17 and GSH 277+00+36. These clouds have been identified in previous work as examples in which molecular gas is either being formed or destroyed due to the influence of the shells. 12CO(J = 1-0), 13CO(J = 1-0), and C18O(J = 1-0) mapping observations with the Mopra telescope provide detailed information on the distribution and properties of the molecular gas, enabling an improved discussion of its relationship to the wider environment in which it resides. We find that massive star formation is occurring in molecular gas likely formed in situ in the shell wall, at a Galactic altitude of ~200 pc. This second-generation star formation activity is dominating its local environment, driving the expansion of a small H II region which is blistering out of the atomic shell wall. We also find new morphological evidence of disruption in two smaller entrained molecular clouds thought to pre-date the shells. We suggest that at the present post-interaction epoch, the lifetime of this surviving molecular material is no longer strongly determined by the shells themselves.

Item Type:	Refereed Article
Keywords:	evolution; ISM: bubbles; ISM: clouds; ISM: molecules; radio lines: ISM; stars: formation
Research Division:	Physical Sciences
Research Group:	Astronomical and Space Sciences
Research Field:	Galactic Astronomy
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Physical Sciences
Author:	Dawson, JR (Dr Joanne Dawson)
Author:	Dickey, JM (Professor John Dickey)
ID Code:	75008
Year Published:	2011
Funding Support:	Australian Research Council (FS100100037)
Web of Science® Times Cited:	15
Deposited By:	Mathematics and Physics
Deposited On:	2011-12-23
Last Modified:	2012-04-13
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