The Physical conditions in Infrared Dark Clouds
René Plume
University of Calgary

Massive star formation plays an integral role in the evolution of galaxies as they are responsible for energizing the interstellar medium, producing the heavy elements, and have been suggested to regulate the rate of star formation. Understanding massive star formation requires detailed observations of the entire process: from the onset of gravitational collapse to the unveiling of the newly formed massive main sequence star. Observations of the initial conditions (i.e. temperature, density, mass, etc.) at each stage are essential to this study. We have learned much about the process of low mass star formation through observations of their initial conditions, yet have had problems constraining the initial conditions for high mass star formation due to their rarity, distance, and much shorter formation timescales. In this talk I will present observations of 41 MSX infrared dark clouds as well as an analysis of their physical conditions. From comparing the observed physical conditions (i.e. line widths, masses, densities, column densities) to previous low-mass and high-mass star formation studies, we have identified these cores as potential regions of high mass star formation. In addition, our result suggest that one core, in particular, may be one of the elusive beasts known as an isolated, massive, pre-protostellar core.

Date:	Jeudi, le 7 janvier 2010
Heure:	11:30
Lieu:	Université Laval
	Pavillon Alexandre-Vachon, local 1661
Contact:	Gilles Joncas