Tidal disruption events (TDEs) are explosive phenomena that shine brightly from optical to X-rays around supermassive black holes (SMBHs), and therefore provide evidence for dormant SMBHs in the centers of inactive galaxies. TDEs occur when a star on a parabolic orbit approaches close enough to a SMBH to be disrupted by the SMBH's tidal force. The subsequent super-Eddington accretion of stellar debris falling back to the SMBH produces a characteristic flare lasting several months. This is the standard picture of TDEs. However, recent progress has gradually unveiled the observed diversity of TDEs. Specifically, AT2019dsg is an unusual type of TDE because it shows bright emission from optical to soft-X-ray wavebands as well as weak but observable radio emission. Moreover, AT2019dsg has very recently represented the first potential association of neutrino emission with a TDE. This talk will briefly review the TDE theory and observation and the association of the IceCube neutrino and AT2019dsg. Besides, I will explain high-energy neutrino emissions from accretion flows around the SMBH.

Page created on April 14, 2021.