中国科学院云南天文台学术报告通知

2024年第22期

报告题目：What does the EDGES measurement really imply for excess radio background models?

报告人：仓俊松 博士

报告人单位：Scuola Normale Superiore di Pisa, Italy

报告语言：中文

报告时间：2024年9月3日 10:00-11:30

报告地点：1号楼412会议室

报告摘要：

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In 2018 the EDGES experiment reported the first detection claim for the global cosmic 21cm signal, which featured an absorption trough centered around redshift 17 with a depth of -500mK. This amplitude is deeper than standard cosmological prediction by a factor of 2 and potentially hints to the existence of excess radio background. This work analyzes EDGES sky temperature data for a realistic astrophysical 21cm model with radio galaxies made of population III stars. We perform likelihood analysis on EDGES sky temperature data in combination with ARCADE2 and Planck measurements of reionisation optical depth. After comparing Bayesian evidences for a broad range of 21cm foreground and calibration models, we show that EDGES actually diafavors a strong cosmic signal beyond the LCDM paradigm, which is qualitatively opposite to previous claims in literatures.

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报告人简介： 

Junsong Cang is a postdoctoral fellow at Scuola Normale Superiore and SISSA in Italy, where he works on 21cm cosmology in collaboration with Prof Andrei Mesinger and Roberto Trotta. He received his PhD in 2023 from the Institute of High Energy Physics, Chinese Academy of Sciences, working on the searches for dark matter and primordial black holes using CMB, 21cm and gravitational wave. His research focuses on the theoretical modeling and numerical simulation of the cosmic 21cm signal during the epoch of reionization, as well as inference techniques for analyzing 21cm data. He is currently working on the data analysis of EDGES and SKA experiments.

云台邀请团组：大样本恒星演化研究团组

邀请方联系人：李振威