Seminar Wenfei Yu: Dormant SMBHs and GR effects: relativistic line reverberation mapping in tidal disruption events
When normal stars run close enough to previously dormant supermassive black holes (SMBHs) at the centres of normal galaxies, they would be entirely or partly disrupted due to the tidal force of the central SMBH, leading to the so-called tidal disruption events (TDEs). Part of the debris material of the disrupted stars will be accreted by the SMBHs afterwards and generate flares usually in the optical and UV bands, and also in the soft and hard X-ray band in many cases, which would illuminate the remaining debris material and generate UV or X-ray spectral line features. Here we show predicted relativistic line features and evolution expected to occur during the accretion phase of the debris material. The line features are imprints of the mass and spin of the SMBHs at the centres of galaxies and bring clues to the geometry of the accretion flow, providing unique probes of the general relativistic Lense-Thirring precession and Bardeen-Petterson effect.
Wenfei Yu ( Shanghai Astronomical Observatory)