SHAO Astrophysics Colloquium（Speak in Chinese）

Title: Hydrogen and Helium Absorption-Lines in Quasars

Speaker: 周宏岩 (中国极地研究中心)
Time:2:30 pm, January 10 (Thursday)

Location: Lecture Hall, 3rd floor

Abstract: 

Being the most luminous steady objects known in the universe, quasars have been a long-standing enigma in modern astrophysics since their discovery. These cosmic beacons are believed to be powered by the gravitational potential energy of accreted matters released in the course of falling into a super-massive black hole. Their energetics and dynamics require massive in-/out-flows that may manifest themselves as broad absorption-lines (BALs) on quasar spectra. However, the commonly observed metal BALs of little diagnostic value in probing these flows of dense gas with high column densities at the heart of quasars, due to serious saturation and line blending effects. I will talk about a novel approach making use of BALs of hydrogen Balmer line series and of meta-stable natural helium line multiplets, including several case stories.

Special Astrophysics Colloquium

Title: A Good Hard Look at Cosmic Supermassive Black Hole Growth

Speaker: Niel Brandt (Penn State University)

Time: 3:00 pm, January 8 (Tuesday)

Location: Lecture Hall, 3rd floor

Abstract: 

The 7 Ms Chandra exposure on the Chandra Deep Field-South (CDF-S) has provided the most sensitive extragalactic X-ray survey by a wide margin. About 1050 X-ray sources have been detected, primarily distant active galactic nuclei (AGNs) and starburst/normal galaxies. The unmatched deep multiwavelength coverage for these sources allows superb follow-up investigations, revealing the details of supermassive black hole growth over most of cosmic time. I will briefly describe the sources in the 7 Ms CDF-S and highlight some exciting science results. The latter will include (1) evidence  for black-hole vs. bulge co-evolution in the distant universe; (2) constraints on supermassive black hole growth in the first galaxies as revealed by direct detection and stacking; and (3) the discovery of a representative of a new population of faint, fast X-ray transient sources. Finally, I will discuss some future prospects for X-ray surveys of AGNs in the distant universe including the ongoing 5 Ms XMM-SERVS survey of the LSST Deep Drilling Fields and new X-ray missions. 

Group meeting

Black hole Accretion and High-energy Astrophysics /Black Hole Feedback and Cosmic Ray Astrophysics Seminar

Location: 1608

Time: 14:00-16:00, Wednesday, Jan 9th

Speaker: Yihuan Di

The Role of Black Hole Feedback on Size and Structural Evolution in Massive Galaxies

http://adsabs.harvard.edu/abs/2018ApJ...866...91C

Speaker: Shaokun Xie

The Origins of the Circumgalactic Medium in the FIRE Simulations http://adsabs.harvard.edu/abs/2018arXiv181111753H