University of Minnesota
School of Physics & Astronomy

Physics and Astronomy Calendar

Friday, December 8th 2017
Speaker: Jeremy Webb, Indiana U
Subject: Do Globular Clusters Have an Identity Problem? - The Dynamics of Mass Segregation and Tidal Stripping
Refreshments to be served in the MIfA Interaction Area (Tate 285-11) following the colloquium.

Globular clusters, once thought to be simple dynamical systems, are proving to be increasingly complex as our observational capabilities continue to grow. Advancements in ground based telescopes in particular have made it possible to study how various cluster properties change as a function of clustercentric distance, as such studies require multiple pointings per cluster. Being able to study the radial dependence of cluster properties allows for the internal dynamical evolution of clusters to be directly probed. Of particular interest is the ability to measure the degree of mass segregation in a cluster as it provides an indication of a cluster's dynamical age. Coupled with estimates of how much mass a cluster has lost since formation, based on its global mass function, it becomes possible to begin piecing together each cluster's dynamical history. In this talk, I will first present a new method for quantifying the degree of mass segregation in a cluster based on the radial variation of its mass function and relate this measurement to a cluster's kinematic properties. I will then illustrate the application of this method to select Milky Way Globular Clusters and discuss how the degree of mass segregation within a cluster is inconsistent with its present day mass function. Potential remedies to this discrepancy will also be discussed.

Faculty Host: Liliya L.R. Williams

The weekly calendar is also available via subscription to the physics-announce mailing list, and by RSS feed.