University of Connecticut

Events Calendar

Physics Colloquium (Prof. Tracy Webb, McGill)

Friday, April 26, 2019
3:30pm – 4:30pm

Storrs Campus
GW-38

Prof. Tracy Webb, Department of Physics, McGill University

The Growth of the Most Massive Galaxies in the Highest Density Regions: Evidence for In-Situ Star Formation in Brightest Cluster Galaxies

The most massive galaxies in the local universe reside at the centres of galaxy clusters. These so-called Brightest Cluster Galaxies (BCGs) exhibit, as a class, highly uniform properties and are distinct from the general galaxy population. This suggests formation processes which are themselves distinct from those which dominate in massive galaxies outside of cluster cores. The mass growth of BCGs is likely linked to the overall physics of hierarchical structure formation on galaxy cluster scales, including the fundamental processes of gas cooling, star formation, energy feedback and galaxy mergers, at the centers of giant dark matter halos. In this talk I will present new results from the largest study of high-redshift BCGs conducted to date, drawn from the SpARCS optical/NIR cluster survey. Using archival infrared data we show the star formation rate within BCGs increases to z~2, and can add as much mass to the BCG population as the previous standard model of growth by dry mergers. At low redshifts, and in X-ray/SZ selected clusters, the rare examples of star forming BCGs appear to be fed by large-scale cooling flows. However, the first of the SpARCS systems we have studied in detail, SpARCS1049, has revealed a very different phenomenon – a train-wreck of a galaxy merger at the center of the cluster. This is the first example of such a process in high-redshift cluster cores and may represent a new phase of BCG evolution, previously unaccounted for.

Coffee and tea will be served prior to the talk, at 3:00 p.m., In Room GW-103

Contact:

Prof. Kate Whitaker

Physics Department (primary), UConn Master Calendar

Control Panel