报告题目：Simulating the galaxy population in LCDM cosmologies

报 告 人：郭琦（国家天文台）

报告时间：10月15日下午2：00

报告地点：蒙民伟科技南楼S727

报告摘要：The LCDM model has been successful in interpreting a wide variety of observations, including the cosmic microwave background fluctuations (CMB), the large-scale clustering of galaxies in the local universe Universe, the high-redshift power spectrum probed by the Lyman α forest, the baryon fractions, and etc. However, dark matter is invisible and verifiable descriptions of the nature and origin of the Universe have to rely on analysis of observables. Galaxy is one of the basic populations of light emitters. They form through the condensation of gas at the centers of a hierarchically aggregating population of dark matter haloes, and are thus excellent tracers of the cosmological structures. The formation of galaxies does not, however, trace that of their dark matter halos in a simple manner, and the exponentially growing body of high-quality galaxy data coming from large surveys cannot be properly compared to the CDM model without a careful treatment of baryonic processes. Such detailed comparison is the most promising route to clarifying the complex astrophysics underlying galaxy formation, and it may also uncover problems with the CDM model which are not evident on larger scales. Despite our success in understanding dark matter dominated structure formation, it is far from clear how galaxies form because this involves more complicated dissipative processes in the non-linear regime. Here I will present the most up-to-date galaxy formation models/simulations in the context of LCDM, and discuss how it help to understand the observed galaxy properties and distributions at various scales.