Title: High-Redshift Quasars and Galaxies at the Epoch of Cosmic Reionization

Speaker: Linhua Jiang(Arizona State University) 

Time & Place: Thursday, 3:00pm, March 6th, Lecture Hall, 3rd floor 

Abstract: In the last decade, we have witnessed great advances in detecting galaxies and quasars at higher and higher redshifts, using both space and ground-based telescopes. These distant objects provide a powerful tool to probe the epoch of cosmic reionization, the last major phase transitions of the Universe. There are two parts in my talk, after a short introduction to cosmic reionization. The first part is about high-redshift (z>=6) galaxies. I will first present physical properties of the largest sample of spectroscopically confirmed galaxies at z>=6. These objects have extremely deep imaging data from the optical bands and HST near-IR bands, to the Spitzer mid-IR bands. The spectroscopic redshifts of the sample and the wealth of the multi-band data provide great advantages to measure various physical properties. Several interesting properties will be shown in this talk. I will then present recent deep spectroscopy of z>7 galaxies, and show what the results tell us about cosmic reionization. In the second part of the talk I will talk about high-redshift (z>=6) quasars. I will mostly review our past and current searches of z>=6 quasars, their physical properties, and implications to reionization. Finally I will briefly mention our future work on this topic. 

Biog: Linhua is a Hubble Fellow in the School of Earth & Space Explorationat Arizona State University. Prior to this he was at the University of Arizona, where he obtained his PhD in 2008, and before that an undergraduate at Peking University. He has over 50 peer-reviewed papers and a number of high-profile observing campaigns. His interests are in extragalactic astronomy and cosmology.