简介: |
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.
个人简介:Dr. Cheng Li (李成) got his PhD in 2006 from University of Science and Technology of China (USTC) in Hefei. He was a postdoc fellow at Max-Planck Institute for Astrophysics (MPA), and has been a research professor and group leader at Shanghai Astronomical Observatory (SHAO) since October 2010. He is supported by the 100-Talent Program of CAS (since 2011) and the National Outstanding Young Scientist Program of NSFC (2013). He has been studying the environment of different types of galaxies using data from the Sloan Digital Sky Survey (SDSS). His current research is focused on galaxy formation and evolution. In particular, he is involved in the 4th generation project of SDSS (SDSS-IV), serving as the SDSS-IV Council representative for SHAO and the Lead Scientist at SHAO for the science collaborations between SHAO and the SDSS-IV. His main interest with SDSS-IV is a full understanding of the star formation quenching processes occurring in local galaxies, expected to be archived based on the 2D maps of recent star formation histories being observed by the SDSS-IV/MaNGA survey.
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