SHAO Astrophysics Colloquia

Title: Observing Galaxies with the Atacama Large Millimeter Array (ALMA)

Speaker: Christine Wilson (McMaster University)

Time: 3 PM, February 16 (Thursday)  

Location: Lecture Hall, 3rd floor  

Abstract:ALMA is a revolutionary new telescope that is dramatically expanding our understanding of the high-frequency radio sky. Astronomers are using ALMA to make exciting new discoveries in topics ranging from star and planet formation to galaxies in the distant universe. I will describe the basic principles that allow ALMA to produce sub-arcsecond radio images and highlight some of the recent exciting results that illustrate the breadth of ALMA's science. I will also describe my recent work with my students and collaborators using ALMA to study nearby merging galaxies.

Seminar talk

Title: Density Waves in Strongly Radiation Pressure Dominated AGN Accretion Disks

Speaker: Yan-Fei Jiang (姜燕飞, UC Santa Barbara )

Time: 10 am, February 16 (Thursday)) 

Location: Middle conference room, 3rd floor

Abstract: AGN unification model is very successful to explain many observational properties of AGNs, however, little progress has been made to understand the physical properties of the inner accretion disks, where most of the photons are emitted. The radiation pressure in the inner region of AGN accretion disks can be 10^4 times larger than gas pressure for most quasars. I will show that in this strongly radiation pressure dominated regime, magneto-rotational instability is inefficient to provide the required angular momentum transfer for the accretion disks. Density waves excited by the turbulent flow can play an important role for the structures of AGN accretion disks. I will show numerical evidences and theoretical understanding of the density waves as well as their implications for AGN accretion disks. 

Group meetings

Galactic Dynamics Group Journal Club

Time & Location: 9:30 AM, Feb. 16th (Thursday), Room 1608

Title: Recent Study on the Galactic Disk Kinematics with Gaia

Speaker: Zhao-Yu Li

Abstract: In this talk, I will review recent papers on the Milky Way disk kinematics based on Gaia DR1. 

References :

Bovy 2016, arXiv:1610.07610

Hunt et al. 2016, ApJL, 832, L25

Hunt et al. 2016, arXiv:1611.00761

Monari et al., 2017, MNRAS, 466, L113