Special Seminar

Speaker: Emil Khabiboulline (Caltech)
Title: How Does Galaxy Environment Influence AGN Activity?
Date (JST): Wed, Aug 28, 2013, 15:30 - 16:30
Place: Seminar Room A
Related File: 1012.pdf
Abstract: The physics behind how a galaxy's central black hole interacts with its environment to produce the active galactic nucleus (AGN) are not well understood, yet AGN are shown to be increasingly important in cosmic evolution. Locally, AGN seem to be triggered by mergers but more externally, the effect of galaxy clusters is less clear. Using the extensive dataset in the Sloan Digital Sky Survey (SDSS), supplemented by improved environmental data on mergers and groups, we conduct a study of AGN activity hoping to form a general picture of the role of environment. We develop a technique to first measure activity as AGN-specific, continuous, and comparable across all SDSS galaxies, then determine enhancement between samples specifically matched to emphasize or marginalize key properties. Our preliminary findings indicate that the local enhancement from merging and external deenhancement from clustering are consistent but that clustering overrides merging in terms of impact on AGN activity.