1. School of Astronomy and Space Science, University of Science and Technology of China , Hefei 230026 , China
2. CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China , Hefei 230026 , China
3. Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences , 19B Yuquan Road, Beijing 100049 , China
4. Kavli Institute for Astronomy and Astrophysics, Peking University , Beijing 100871 , China
5. Department of Astronomy, School of Physics, Peking University , Beijing 100871 , China