The Multiwavelength Perspective on Gas, Dust and Star Formation in Nearby Galaxies

Fri, November 20, 2015

Colloquium image for website

The efficiency at which interstellar gas is converted into stars is one of the major factors governing the evolution and observable properties of galaxies at all redshifts.  In the Milky Way we can study the star formation process in great detail, but only over a limited range of environmental conditions.   We must move to nearby galaxies to expand this range.  Over the last several years, multiwavelength surveys of nearby galaxies have provided key, new insights into the connection between star formation and the amount and properties of gas in the interstellar medium (ISM).  I will present the results of work improving the accuracy with which we trace molecular gas—a key ingredient for forming stars.  Using our improved assessment of the molecular gas distributions in nearby galaxies, we can study star formation efficiency under a variety of environmental conditions.  While molecular gas is converted into stars with a constant efficiency in most regions of nearby galaxies, some galaxy centers appear to have enhanced efficiency, similar to what has been observed in starbursts induced by galaxy mergers.  I will also discuss the degree to which molecular gas is concentrated in the centers of barred galaxies and how this influences our understanding of secular evolution.  Finally, I will discuss the key future directions for studying the ISM and star formation in galaxies.