1. Kavli Institute for Astronomy and Astrophysics, Peking University , Beijing 100871, China
2. Department of Astronomy, Tsinghua University , Beijing 100084, China
3. Department of Astronomy, University of Massachusetts Amherst , MA 01003, USA
4. Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China , Hefei, Anhui 230026, China
5. School of Astronomy and Space Science, University of Science and Technology of China , Hefei 230026, China