报告人

李志远教授

报告人单位

南京大学

时间

2018年06月19日上午 8：15-10:15

地点

东七楼，四楼427会议室

邀请单位

粒子与天体物理研究所

报告人简介：

Zhiyuan Li （李志远）is currently a Professor of Astronomy at Nanjing University. He obtained his Bachelor and Master degrees in Astronomy at NJU, his PhD degree in Astrophysics at the University of Massachusetts. He was then a postdoc at the Smithsonian Astrophysical Observatory and an assistant researcher at UCLA, before joining the faculty of NJU in 2013. His research is focused on high-energy astrophysics in the context of galaxy evolution, using a multi-wavelength approach.

报告摘要：

X-ray-emitting, close binary systems involving a black hole (BH), a neutron star (NS) or a white dwarf (WD), are among the first objects discovered in the X-ray sky and now understood to be ubiquitous in the Universe. As such, X-ray binaries can serve as a useful tool to study their parent stellar populations, in particular dense star clusters, which are characterized by a variety of dynamical processes, including binary formation and disruption, stellar mergers, and mass segregation. In this talk, I will present our recent work on the X-ray binaries, in particular CVs (i.e. accreting WDs), in globular clusters as well as in the Nuclear Star Cluster (NSC) of our Galaxy, based on Chandra observations. In Galactic globular clusters, we find that the abundance of CVs is on average lower than that in the field, which can be understood as an efficient disruption of primordial binaries due to binary-single encounters. In the NSC, however, we find no clear sign of dynamical effects on the abundance and spatial distribution of CVs, despite the high stellar density and the presence of a massive black hole. On the other hand, we are able to place a strong constraint on the number of NS- and BH-binaries in the NSC. Some other interesting implications on these close binary systems will be discussed.