Tsukuba Uchu Forum

20th Uchu Forum

The role of environment on the mass buildup of supermassive black holes

John Silverman

Kavli IPMU


The immediate environment of galaxies is known to influence their growth through various physical processes. Given the close connection between galaxies and their supermassive black holes, as seen through a number of observed relations (e.g., M-sigma), we expect to find that the environment plays a role in regulating the level of AGN activity. I will present results from an observational study using the zCOSMOS spectroscopic survey and XMM-Newton observations to determine if the environment is responsible for driving the order-of- magnitude decline in star formation and AGN activity from z~1 to the present. Furthermore, I will show preliminary results from a complementary study to look more closely at AGN activity in nearby galaxy groups (z~0.05), an environment thought to be highly conducive to black hole growth given the heightened efficiency for galaxy mergers.