Using broad emission lines of quasars to... Dr. M. Eracleous

Event Date: Friday, April 15, 2016

Department of Physics and Astronomy

PHYSICS & ASTRONOMY COLLOQUIUM

Dr. Michael Eracleous

Department of Astronomy & Astrophysics
The Pennsylvania State University

"Using the broad emission lines of quasars to study the dynamics of gas in the accretion flow"

ABSTRACT

The broad emission lines of quasars are now used as tools to study the properties of the gas in the immediate vicinity of the supermassive black holes. Examples of such applications include estimating black holes masses, probing the dynamics of the accretion flow, and searching for binary supermassive black holes. The utility of the broad lines as tools depends on our understanding of the structure of the gaseous medium that emits them, the "broad-line region." In this talk I will begin by summarizing what we know about the broad-line region and introduce some of the physical models that have been devised to describe it. I will then talk about projects that my collaborators and I have been carrying out in which we make use of the long-term variability of the broad emission lines. In one of these projects we exploit the variability of the line profiles on time scales of several years to probe the dynamics of the accretion disk that feeds the supermassive black hole. Through these studies we are arriving at a picture in which the accretion disk is massive and self-gravitating.

Coffee will be available in the Atrium, 2nd floor, at 1:15 p.m.

We look forward to seeing you at the Colloquium! As a courtesy to the speaker and audience, please set your cellphones to “silent” mode. Thanks!

Using broad emission lines of quasars to... Dr. M. Eracleous