Physics Colloquium

The Department of Physics has a long tradition of organizing and hosting the Physics Seminars. This weekly event series serves as a major window into the new and exciting world of modern physics. Invited speakers from all branches of physics have been giving Colloquia on our campus for students and faculty.

Friday, March 3, 2017

Time: 10:50am - 12:20pm

Location: Main 1.224 (Brownsville), EACSB 1.104 (Edinburg)

Multiwavelength Diagnostics of Quasar Accretion Power

Understanding the growth of supermassive black holes (SMBHs) and the assembly of their host galaxies relies critically on obtaining reliable estimates of SMBH mass and accretion rate. Traditional methods of estimating these parameters in quasars, particularly those at high redshifts, suffer from biases and large uncertainties, thus yielding only loose constraints on models of SMBH growth in the early universe. I will describe the development of a prescription for obtaining the most reliable and practical SMBH mass and accretion rate indicators in quasars. The project involves a comprehensive multiwavelength investigation of such sources having wide ranges of redshift and luminosity. This prescription will be particularly valuable for investigating thousands of quasars at redshifts greater than 6 that will be discovered by next-generation multiwavelength surveys.

Speaker: Dr. Ohad Shemmer (University of North Texas)

About the speaker: Dr. Ohad Shemmer is an Associate Professor at the University of North Texas Department of Physics.  He earned a Ph.D. in 2005 from Tel Aviv University.  During 2004-2008 he worked as a postdoctoral researcher and as a research associate at The Pennsylvania State University, where he has performed multiwavelength studies of active galactic nuclei (AGN) and quasars.  Since joining the faculty at the University of North Texas in 2008, he has supervised more than 20 undergraduate and graduate students in a variety of astrophysical projects.  He has published over 70 articles in refereed journals, and has been awarded over $600k in Federal funding.  Professor Shemmer serves regularly on NSF, NASA, and European Space Agency review panels, and he is a member of the American Astronomical Society and the Large Synoptic Survey Telescope AGN Science Collaboration.