Title: Reverberation lags viewed in hard X-rays from an accreting stellar-mass black hole

Speaker: 游贝

Institute: 武汉大学

Host: 马任意、孙谋远

Time: 2026.3.26 周四 14:30

Location: 物理楼 552

Abstract:

In a BHXRB, the X-ray emitting region is far too small to be directly imaged, but rapid variability of the X-ray signal can be used to infer the geometry by measuring time lags caused by material propagating towards the black hole and by coronal X-rays reflecting off the disk to imprint a reverberation lag. In this talk, I will introduce our recent theoretical/observational studies on the X-ray fast variability with HXMT observations. On short-timecale, we report on the first detection of the Compton hump reverberation feature from an X-ray binary, achieved by measuring lags in the broad energy range of 1-150 keV; On long-timescale, the lag measurements up to the highest energy to date reveal that this lag evolves dramatically on timescales of days. These discoveries helps us mapping the accretion flow at the very beginning of the outburst and its evolution.

Bio:

Dr. Bei You is a professor at the School of Physics and Technology at Wuhan University and a recipient of the Xiaomi Young Scholar Award. He earned his PhD from Shanghai Observatory in 2014. After that, he worked as a postdoc at the Nicolaus Copernicus Astronomical Centre (NCAC) in Poland from 2014 to 2017. In October 2017, he began working at Wuhan University. His long-term research focuses on black hole accretion and jets, primarily studying energy spectra and temporal variations during outbursts in black hole X-ray binaries. He has published papers in international journals such as Science and Nature Communications, uncovering the physical processes of black hole accretion and magnetic field transport.

Related papers:

See the attachments