In the standard LambdaCDM cosmological framework, cosmic structures grow through a hierarchical process. As fundamental building blocks of the dark matter universe, halos are believed to follow a self-similar structure distribution. Thus, we could stacking the weak lensing signal of multiple halos with the galaxy-galaxy lensing (gglens) method, and obtain the average profile of halos. (A.) With this method, we have measured the concentration-mass (c-M) relation, which encodes the key information of the assembly history of the dark matter halos, and made the first observation of its upturn tendancy at the high-mass end. (B.) We also made the systematic measurement of the splashback radius for halos covering the largest mass range and largest redshift range, and find a consistent result with the simulation. (C.) In addition, we also decompose the stellar and dark matter profile by combining the gglens and kinematical information. (D.) Furthermore, we studied the mass-loss of subhalo due to tidal stripping, and found direct observational validation for theories of galaxy formation. Finally, CSST has a great potential for providing us more accurate constraint of the profile of dark matter halos.
BIO
Dr. Xu is now working as an assistant researcher in National Astronomical Observatories, Chinese Academy of Sciences (NAOC), after her three years postdoc at KIAA at Peking University. She received her PhD in 2019 from NAOC. From 2016 to 2018, Weiwei visited the Argelander Institute for Astronomy, University of Bonn. Her research interests include the weak lensing effect of the dark matter halos and the X-ray research about galaxy clusters.
Host: Shuo Zhang
