题目：Supersoft Ultraluminous X-ray Sources
报 告 人：冯骅 教授
摘 要：Ultraluminous X-ray sources (ULXs) are non-nuclear objects found in external galaxies that appear to be very luminous under the assumption of isotropic emission. X-ray spectroscopic and timing studies suggest a new accretion state distinct from those seen in Galactic stellar-mass black hole binaries. I will focus on a sub-class of ULXs whose X-ray spectra are dominated by soft thermal emission. These supersoft ULXs show similar spectral and temporal behaviors and may define a new emission state with an even higher accretion rate compared with standard ULXs.