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BioYifan is a PhD student in Geophysics, advised by Prof. Greg Beroza. His research interests include earthquake source study, location, and machine learning. He received bachelor degree in geophysics from Nanjing University.

Contact Info
Mail Code: 2215
yuyifan@stanford.edu

Yijun Yu

Affiliate, Applied Physics

Zhefu Yu

Postdoctoral Scholar, Physics

Current Research and Scholarly InterestsMy research aims to understand how supermassive black holes (SMBHs) grow over cosmic time, one of the key questions in astrophysics.

I have done substantial work in accurately measuring the mass of SMBHs through reverberation mapping (RM). In particular, I derived a new relationship between the radius of the Mg II broad line region and the continuum luminosity of the active galactic nuclei (AGN) based on the OzDES RM project, which is critical for SMBH mass measurements and demographic studies in cosmic noon – the peak of AGN activity. I have also done extensive work in understanding the accretion physics in both AGN and quiescent SMBHs.

Now my work focuses on better understanding the accretion onto SMBHs, the major path of SMBH growth. I collaborate closely with the XOC group and the Rubin LSST team in KIPAC. My research probes the inner most region of the AGN accretion disk through joint analysis of the X-ray spectral and timing data. I will also probe the accretion disk through time domain analysis of the LSST data in the near future.