Date/Time
Date(s) - 13/10/2010
3:20 pm - 4:20 pm

Title: FORMATION AND EVOLUTION OF STAR CLUSTERS

Speaker: Dr. Michael Fall, STScI

Institute: Space Telescope Science Institute

Location: ABB 102

Description:

Most if not all stars form in clusters embedded in the densest parts of interstellar molecular clouds. The radiative and mechanical energy and momentum input by massive stars (“feedback”) within these protoclusters then expels much of the gas, thus ending further star formation and leaving many of the clusters gravitationally unbound, with their constituent stars free to disperse into the surrounding stellar field. The clusters that survive this initial period of disruption (“infant mortality”) are then further eroded by a variety of physical processes, until eventually, after a Hubble time, nearly all clusters have been destroyed, leaving behind only the most massive of them, the globular clusters. Most stars are born in clusters, but very few of them remain in clusters. Thus, nearly all baryons within galaxies pass through star clusters on their way from the clumped interstellar medium to the smooth field stellar population. As I will show in this colloquium, this whole complex sequence of events, the life cycles of star clusters, can be boiled down (approximately) to a relatively simple physical description.
I will also present observational evidence that this description applies (approximately) in a wide variety of environments, from dwarf to giant galaxies, and from quiescent to interacting galaxies.