Exploring the Inner Structure of Active Galactic Nuclei by Reverberation

Peterson, Bradley M.

Title:

Exploring the Inner Structure of Active Galactic Nuclei by Reverberation

dc.contributor.author	Peterson, Bradley M.
dc.contributor.corporatename	Georgia Institute of Technology. School of Physics	en_US
dc.contributor.corporatename	Ohio State University. Dept. of Astronomy	en_US
dc.date.accessioned	2016-11-14T19:20:28Z
dc.date.available	2016-11-14T19:20:28Z
dc.date.issued	2016-10-31
dc.description	Presented on October 31, 2016 at 3:00 p.m. in the Marcus Nanotechnology Building, Room 1117	en_US
dc.description	Bradley M. Peterson is the former Chair (2006-2015) of the Department of Astronomy at The Ohio State University. His research is directed towards determination of the physical nature of active galactic nuclei (AGNs). These are the most luminous discrete sources in the Universe, as bright as an entire giant galaxy of normal stars, but are nevertheless very compact, only about the size of the Solar System. The immediate goal of most of my recent research has been to probe the inner structure of AGNs on the smallest possible scales through studies of continuum and emission-line variability, a process known as "reverberation mapping." Reverberation mapping allows us to measure directly the masses of the black holes at the centers of active galactic nuclei.	en_US
dc.description	Runtime: 59:18 minutes	en_US
dc.description.abstract	The innermost structure of active galactic nuclei (AGNs) consists of an accretion disk surrounding a supermassive black hole and, on somewhat larger scales, rapidly moving diffuse gas. The ultraviolet through near IR spectrum of AGNs is dominated by thermal continuum emission from the accretion disk and broad emission lines and absorption features from the diffuse gas. The continuum flux from the accretion disk varies with time, and the emission lines also change in brightness, or “reverberate,” in response to these variations, with a delay due to the light-travel time across the line-emitting region. Measurement of the emission-line time delay yields the size of the line-emitting region and by combining this with the emission-line Doppler width, the central black hole mass can be inferred. I will discuss results from recent “reverberation mapping” experiments, including a 179-orbit HST Cycle 21 program, that have been designed to explore the dynamics of the emission-line gas and are yielding a wealth of new and quite surprising information about AGN structure.	en_US
dc.format.extent	59:18 minutes
dc.identifier.uri	http://hdl.handle.net/1853/56020
dc.language	English	en_US
dc.publisher	Georgia Institute of Technology	en_US
dc.relation.ispartofseries	Physics Public Lecture Series
dc.subject	AGN structure	en_US
dc.subject	Black hole	en_US
dc.subject	Doppler	en_US
dc.subject	HST cycle 21	en_US
dc.title	Exploring the Inner Structure of Active Galactic Nuclei by Reverberation	en_US
dc.type	Moving Image
dc.type.genre	Lecture
dspace.entity.type	Publication
local.relation.ispartofseries	School of Physics Public Lecture Series
relation.isSeriesOfPublication	f931f7b7-fef6-4b8f-b8a7-d8b64b5536bd