报告题目：Galaxy Properties and Galaxy Environment

报 告 人：Cheng Li,Shanghai Astronomical Observatory

报告时间：2015年6月2日16：00

报告地点：理科楼三楼报告厅（C302）

报告摘要：Galaxy formation and evolution is believed to be driven by both secular processes happening within galaxies and external environmental effects occurring within/around their host dark matter halos. Thanks to large redshift surveys, particularly the Sloan Digital Sky Survey (SDSS) which provided high-quality single-fiber spectroscopy for hundreds of thousands of galaxies in the nearby universe, our understanding of galaxy environment has improved dramatically in the past one decade and a half. The SDSS project has started its 4th generation and the SDSS-IV/MaNGA survey will obtain two-dimensional spectroscopy for a uniform sample of 10,000 galaxies by utilizing Integral Field Units (IFUs), thus for the first time allowing statistical studies of the internal properties of galaxies and their environment simultaneously. In this talk, I will present our studies of galaxy environment that we have done in the past 10 years based on the SDSS data. It is found that galaxy environment depends on a variety of global properties including star formation rate, structural properties, nuclear activity and cold gas content. I will then talk about our ongoing works, understanding the internal properties of galaxies using the increasing sample of IFU data being produced by MaNGA. I will show that, with a current sample of only 700 galaxies, the MaNGA data has already revealed a nice picture of "inside-out quenching" in which star formation gets shut down first in the galactic center, before extending to larger and larger radii.