Signatures of Cosmic Reionization on the 21cm 3-Point Correlation

主讲人 (Speaker): 
Kai Hoffmann
主讲人单位 (Speaker's Institute): 
清华大学天体物理中心
邀请人 (Invited by): 
陈坤全
时间 (Time): 
星期二, 2018/04/24 - 15:00 to 16:00
地点 (Location): 
珠海校区海滨红楼17栋107 (Rm 107, Red House 17)
摘要 (Abstract): 

Constraints on reionization models from future 21cm observations will rely on the statistical characterization of
the spatial fluctuations in the observed 21cm brightness temperature. So far studies have focused almost exclusively
on second-order statistics, such as 2-point correlations, to characterize these fluctuations, neglecting a significant
amount of information, which is encoded in the higher-order statistics. I will present a study of the 21cm 3-point correlation in configuration space, as predicted by a semi-numerical simulation. The results show a strong dependence of the 3-point correlation on the triangle opening angle, as we probe the morphology of large-scale fluctuations in the 21cm signal. This
behaviour changes strongly for different reionization scenarios and can hence tighten observational on the latter. I will further present a simple analytical model for a physical interpretation of the 21cm 3PCF measurements in simulations.

主讲人简介 (Speaker's CV): 
Kai Hoffmann studied physics at the Universities of Florence (Italy) and Potsdam (Germany) and completed master at the Leibnitz-Institut für Astrophysik Potsdam in 2011. He then moved to Spain, where he obtained his PhD in 2015 at the Institute of Space Sciences in Barcelona. Since 2016 he holds a postdoc position at the Tsinghua Center for Astrophysics in Beijing. His research covers topics related to observation cosmology, in particular large-scale structure statistics, galaxy clustering bias, intrinsic galaxy alignment and the epoch of reionization.