Title：The properties of UCDs in the Virgo cluster

　　Speaker：刘成则（上海交通大学)

　　2009年6月于中国科学院上海天文台获博士学位

　　2009年7月至2011年6月在北京大学做博士后

　　2011年7月起任上海交通大学物理系助理研究员

　　从事天体物理研究工作。主要通过分析多波段巡天数据，研究星系的形成和演化。

　　Abstract：The classic separation between galaxies and star clusters based on properties such as size and luminosity has become increasingly blurred since the discovery of a family of compact stellar systems that are intermediate between compact elliptical galaxies (e.g., M32) and the most massive globular star clusters. These “ultra-compact dwarfs”(UCDs),or “dwarf-globular transition objects”(DGTOs), have sizes 10＜rh＜100 pc and luminosities of MV＜-9 mag, and are of indeterminate origin. Their properties are similar to both the nuclei of low-mass galaxies, and to massive globular clusters (GCs), suggesting possible connections to both of those populations. UCDs have so far been found mostly in dense environments, at the centers of galaxy clusters, or near massive galaxies, implying that environmental effects, such as tidal stripping, may play an important role in their formation. It is also possible that UCDs formed as compact galaxies at early times when the universe was much denser, or are simply the massive extension of the GC population. In this talk, I will report the latest results of UCDs in Virgo cluster based on the Next Generation Virgo cluster Survey (NGVS).

　　Time：March 23 (Wednesday), 16:00pm

　　Place：Room 402, Astronomy Building

欢迎各位老师、同学参加！

　　                                              南京大学天文与空间科学学院