Detecting Signatures of Lense-Thirring Precession in Black Hole Accretion Flows

by Qingcang Shui (Chinese Academy of Sciences)

Thursday 5 Feb 2026, 21:20 → 21:40 Asia/Shanghai

Tsung-Dao Lee Institute

Host: Dong Lai
Location: Online

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Meeting ID: 613535699 (no password）

Abstract:
Dynamic processes in the accretion flow near black holes produce variable X-ray signals. Among them, low-frequency quasi-periodic oscillations (LFQPOs), observed as nearly periodic X-ray flux modulations on second timescales in stellar-mass black holes, have remained a long-standing and actively debated puzzle. A leading theoretical interpretation attributes LFQPOs to general relativistic Lense-Thirring precession of the tilted, hot accretion flow. Despite its broad appeal, direct observational confirmation of this mechanism has been elusive. 
In this talk, I will present a novel data-analysis framework, developed in close connection with the theoretical model, to search for observational signatures of accretion flow precession. Applying this method to X-ray observations, we report a significant detection of the characteristic “smoking-gun” signatures predicted by the precession model, providing strong support for this scenario. I will also discuss future extensions of this approach, aimed at reconstructing the precession geometry and constraining the black hole spin orientation, with important implications for accretion physics and binary evolution.

Biography:
Qingcang Shui (税擎苍) is a PhD candidate at the Institute of High Energy Physics, Chinese Academy of Sciences, and is currently an academic visitor at Newcastle University, the United Kingdom. He received his BSc degree from Shandong University in 2021. He is mainly engaged in the study of accreting black holes and other X-ray transients based on novel X-ray data-analysis techniques and numerical simulations. As an associate member, he is actively involved in the operations of the Einstein Probe mission and has contributed to the science white paper for China’s next-generation flagship X-ray observatory, eXTP. To date, he has published more than 40 papers, including 15 as first or corresponding author.