Speaker
Description
It is still in dispute the existence of intermediate-mass black holes (IMBHs) with a mass of ~10^3-10^5 solar masses (Msun) which are the missing link between stellar-mass black holes (5-50 Msun) and supermassive black holes (10^6-10^10Msun). Many candidates have been proposed including the black holes in dwarf galaxies, globular clusters, and hyperluminous off-nuclear X-ray sources. Until recently, the bright flares from tidal disruption events (TDEs) provide a new and direct way to probe IMBHs. In this talk, we will report our search for the X-ray quasi-periodicity oscillation signal from IMBH TDEs, and the discovery of a transient X-ray QPO with a period of ~85 second (at a significance of >3.5 sigma). Combining with the results from X-ray continuum fittings, the detection of QPO allows for joint constraints on the black hole mass and dimensionless spin in the range [9.910^3-1.610^4Msun] and [0.26-0.36], respectively. This result supports the presence of an IMBH with a low spin, and may open up the possibility of studying IMBHs through X-ray timing of TDEs, such as EP.
