题目：X-ray Spectral and Optical Properties of Ultra Luminous X-ray Sources in Nearby Galaxies

　　报告人：Prof. Aysun Akyuz

　　(Department of Physics, University of Cukurova, Adana, Turkey)

　　摘要：Ultraluminous X-ray sources (ULXs) are variable, nonnuclear X-ray sources with isotropic luminosities (Lx > 1039 erg s-1) above the Eddington limit for a 10 (M⊙ ) black hole. In this presentation, I will review the main properties of ULXs and their popular spectral models. As part of our work, spectral and temporal characteristics of some ULXs are presented.?Also? the properties of the optical counterparts and constraints on their physical nature from multiband optical spectra are discussed.

　　时间：2015年12月1日（星期二）下午3:00

　　地点：紫台大楼 317会议室

欢迎大家积极参加！

　                                             　紫金山天文台学术委员会