Seminar - Jianmin Wang (Beijing Institute of High Energy)

Location: Multifunctional Hall on the 5th floor Meeting time: 2021/04/27 14:00-15:00 (CST)

Speaker: Jianmin Wang (Beijing Institute of High Energy)

Supermassive black holes in quasars for the Hubble tension

Jianmin Wang Seminar

Abstract

One supermassive black hole (SMBH) has been found in the center of Milky Way, which was awarded the Nobel Physics Prize in 2020. Quasars as monsters in the Universe are known to contain accreting SMBHs from their surroundings in galactic nuclei. Optical and ultraviolet spectra of quasars are characterized by broad emission lines with full-width-half-maximum of a few 1000km/s, which is called as broad-line region (BLR). Thanks are given to GRAVITY/VLTI for its powerful spatial resolution of the BLR of the first quasar 3C 273, and its angular size was measured, recently. In the meanwhile, reverberation mapping (RM) campaign is able to accurately measure the linear size of the broad-line region. Joint analysis of GRAVITY and RM data allows to have both the distances and SMBH mass simultaneously, providing a geometric measurement of cosmic distances. This accurate measurement is totally different the classical tools, such as Cepheid stars, type I supernovae and baryon acoustic oscillation. This will greatly help solve the Hubble tension.

Bio

Wang Jianmin is currently a researcher at the Institute of High Energy Physics, Chinese Academy of Sciences. He graduated from the Department of Applied Physics, National University of Defense Technology in 1987, and received his Ph.D. from the University of Science and Technology of China in 1995. He has been selected into the “Hundred Talents Program” of the Chinese Academy of Sciences and won the Outstanding Youth Fund of the National Natural Science Foundation of China. He was awarded the “Huang Runqian Astrophysics Research Award” of the 4th Chinese Astronomical Society and the special government allowance of the State Council. He has been engaged in the research of supermassive black holes and quasars for a long time, and is currently presiding over the major project of the National Foundation of China National Natural Science Foundation of China, “Reflection Mapping Observation and Theoretical Research of Supermassive Black Holes”.