1. California State University Northridge, Physics and Astronomy Department, 18111 Nordhoff Street, Northridge, California 91330, United States
2. Chinese Academy of Sciences, National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology, Nanjing 210042, ChinacChinese Academy of Sciences, Nanjing Institute of Astronomical Optics and Technology, Key Laboratory of Astronomical Optics and Technology, Nanjing 210042, China