Speaker
Joanne Dawson
(CSIRO Astronomy and Space Science)
Description
I will examine the role of large-scale stellar feedback in the formation of new molecular clouds. The theoretical context for this is the compression, cooling and fragmentation of the atomic medium in turbulent shocks and flows, of which the ubiquitous ""supershells"" formed by multiple supernovae and stellar winds are one example. I will first report CO(J=1-0) and HI 21cm observations of the molecular and atomic ISM in two Milky Way supershells, which demonstrate an enhanced level of molecularisation over both objects, and hence provide evidence of increased molecular cloud production in volumes affected by large-scale stellar feedback. I will then discuss recent work on the Large Magellanic Cloud (LMC), in which we have carried out the first quantitative measurements of feedback-triggered molecular cloud formation in an entire galactic system. Our results suggest that ~< 5-10% of the total molecular mass in the LMC may have been formed as a direct result of large-scale stellar feedback. This approximate lower limit places constraints on the importance of OB-cluster feedback in the formation of new star-forming clouds, and suggests that it is not a dominant driver of molecular cloud production in the LMC.
Author
Joanne Dawson
(CSIRO Astronomy and Space Science)