1. Astronomy Department, School of Physics, Peking University, 100871 Beijing, China
2. Kavli Institute for Astronomy and Astrophysics at Peking University, 100871 Beijing, China
3. National Astronomical Observatories and Key Laboratory of Computational Astrophysics, Chinese Academy of Sciences, 20A Datun Rd., Chaoyang District, Beijing 100012, China
4. Institute of Applied Mathematics, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190, China