报告题目：Gas in Galaxies

报 告 人：王杰(National Astronomical Observatories)

报告时间：2016年6月16日（周四）下午2：00

报告地点：蒙民伟科技南楼S527

报告摘要：I will talk about two projects we finished recently.In the first part,we checked the dependence of HI component in galaxies on environment in a matched ALFALFA 70 and SDSS 7 sample. We found 1) the HI detection fraction HI is significantly different in different environment. 2)The HI fraction of the satellites indicates they are suffering stripping in galaxy groups 3) The galactic conformity is also found by the view of HI component in our big sample.In the second part. I will talk about a well known problem -- spin-misalignment between the dark matter halo and the gas halo inside. By tracing the accretion history of gas and dark matter halo separately in a hydrodynamic simulation, we found the gas and dark matter within the virial radius actually are from different places at initial time. The different origin of these two components is the main reason for the spin misalignment at present. Actually the tidal torque field at large scale plays a minor role.