SHAO Astrophysics Colloquium

Title: Understanding connections between star formation and dust obscuration in galaxies over time

Speaker: Prof. Xianzhong Zheng (PMO)

Time: 3:00 pm, October 31st (Thursday)

Location: Lecture Hall, 3rd floor

Abstract: About half energy of the radiation from cosmic star formation is absorbed and re-emitted by dust into the far-infrared.  How dust obscures star formation in galaxies across cosmic time remains to be explored.  In this talk, I will present recent progresses in exploring the relationships between star formation, dust obscuration (IRX=L_IR/L_UV)  and other galaxy parameters.   Recently, we found that dust obscuration of star-forming galaxies obeys an empirical relation, jointly determined by IR luminosity, galaxy size, metallicity and axial ratio.  This empirical relation also holds for distant SFGs out to z = 3 in a population-averaged sense, suggesting it to  be universal across cosmic age. This universal relation reveals that star formation, structure buildup and chemical enrichment are closely linked with each other in the mass assembly of galaxies.  The implications to galaxy evolution will be discussed. 

Bio: XianZhong Zheng is a professor in Purple Mountain observatory, CAS,  and leading a research group on galaxy formation and wide-field survey. He obtained his PhD in astrophysics in 2002 from the National Astronomical Observatories, CAS, and worked as a postdoctoral fellow in Observatoire de Paris-Meudon and the Max-Planck Institute in Astronomy (MPIA) in Heidelberg from 2003 to 2007. He joined Purple Mountain Observatory in 2007 with support by the CAS hundred Talents Program. His research works were mostly on observational studies of galaxy formation and evolution, producing 80 publications.  He was also leading the 2.5meter wide-field survey telescope (WFST) project, recently funded by university of Science and telescope of China.