Title: Mid-Infrared Selected Dust-Rich Quasars: Recovering the Extended Quasar Population　　  

　　Speaker: Y. Sophia Dai （Caltech-IPAC）　　  

　　Time: Tuesday,2:00pm, Dec 2　　  

　　Location: the big conference room　　  

　　Abstract: Quasars are shining beacons in the universe that enlightens us of the path to galaxy formation and evolution. However, there is no consensus on the physics of how quasars and their host galaxies interact. The statistical properties of quasars are therefore of critical values to our understanding of how the universe evolves to its present form, and what physical processes were involved in the active galaxy evolution stage. While many quasar samples to date underlines the point-source nature of unobscured quasars, we select an isotropic quasar sample, a 'dust-rich' population, based on Spitzer MIPS flux and MMT spectroscopy. I will present the results of the study, including the recovery of a significant subgroup of extended objects, the implications on quasar-host connections, as well as ongoing efforts to study the obscuration via absorption features