8-12 juin, 2014

Résumé

Dark Matter Haloes and Globular Cluster Populations: What's the Connection?

Gretchen L. H. Harris (University of Waterloo)

Michael J. Hudson (University of Waterloo), William E. Harris (McMaster University)

There have long been indications that the size of a galaxy’s globular cluster (GC) population is correlated with its dark matter halo, but these studies have built on modest numbers of galaxies and halo mass determinations based on models. We have now combined a new database of GC populations in >400 galaxies with a new observational calibration of halo mass based entirely on weak lensing. We find that the ratio of the mass in a GC system to the galaxy halo mass is nearly constant over >4 orders of magnitude, with intrinsic scatter ±0.2 dex. Implications of this result are that (a) we can accurately estimate a galaxy’s halo mass simply by counting its globular clusters, and more importantly (b) a high fraction of the initial gas mass present in proto-galaxies collected into very large GMCs capable of forming globular clusters.
(doit être confirmé par le SOC)