1. Shanghai Astronomical Observatory, Chinese Academy of Sciences , Shanghai 200030 , China
2. School of Physics and Astronomy, Shanghai Jiao Tong University 800 Dongchuan RD., Minhang District, Shanghai 200240 , China
3. Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences , Hangzhou 310124 , China
4. School of Astronomy and Space Science, University of Chinese Academy of Sciences , Beijing 100049 , China
5. Taiji Laboratory for Gravitational Wave Universe (Beijing/Hangzhou), University of Chinese Academy of Sciences , Beijing 100049 , China
6. Institute for Gravitational Research, School of Physics and Astronomy, University of Glasgow , Glasgow G12 8QQ , UK