Title: Exploring the Cosmic Reionization via Surveys for Emission-Line Galaxies/ 基于发射线星系巡天探索宇宙再电离
Speaker: 郑振亚
Institute: 上海天文台
Host: 王俊峰
Time: 2024.9.12 周四 14:30
Location: 物理楼 552
Abstract:
Large space telescopes, such as HST,JWST and our future CSST, are helping us gradually unveil the mystery of the early universe. It involves the birth and evolution of early stars, galaxies, and black holes. The ionizing photons produced by these objects reionize the neutral hydrogen environment throughout the universe, which is a key process of our universe also known as cosmic reionization. In this talk, I’ll introduce our probes on reionization based on emission-line galaxy surveys for galaxies in the early universe, such as our LAGER/CIDER surveys, our HST narrowband deep field HDHa project, our local analogs study by LAMOST/SDSS, and deep fields and ultraviolet observations by JWST/HST, to study the ionization history, physical processes, and evolution of objects in this epoch from an observational perspective. The main contents of the talk include: (1) study of the reionization history in the universe near redshift 7 based on our LAGER and CIDER surveys; (2) research on galaxies and protoclusters in the epoch of cosmic reionization and their local analogs based on JWST and LAMOST/SDSS surveys; (3) research on the escape of ionizing photons in the process of cosmic reionization based on HST and CSST surveys.
当前正在运行和建造的先进望远镜如HST、JWST、CSST等正在帮助我们逐步揭开早期宇宙的神秘面纱。它涉及宇宙中早期天体,即恒星、星系和黑洞的诞生和演化,及其所产生的电离光子重新电离整个宇宙中的中性氢环境,该过程又被称为宇宙再电离。报告将基于针对早期宇宙星系的发射线星系巡天,包括LAGER和CIDER巡天、HST窄带深场HDHα项目,以及JWST/HST等深场和紫外观测,从观测上介绍对宇宙再电离的电离历史、物理过程和此时期天体演化的相关研究。报告重点介绍:(1)基于LAGER和CIDER等巡天的红移7附近的宇宙再电离历史研究;(2)基于JWST和LAMOST/SDSS等巡天的再电离时期星系和原初星系团及其近邻对应体的研究;(3)基于HST和CSST等观测的再电离过程中电离光子逃逸问题研究。
Bio:
郑振亚,中科院上海天文台研究员,“早期宇宙与高红移星系”课题组长,光学天文技术研究室副主任(主持工作),中国科学院特聘研究岗位(核心)。先后在2006年和2012年获得中国科学技术大学天文学学士和天体物理学博士学位,之后在美国亚利桑那州立大学和智利天主教大学开展博士后研究工作,于2016年入职上海天文台任研究员至今。目前联合承担空间站光学巡天望远镜后端多通道成像仪MCI载荷的研制任务(担任MCI责任科学家),并主持科技部重点研发专项课题。曾主持自然科学基金优青项目和面上项目、中科院高层次人才青年项目、上海市浦江人才项目。主要研究兴趣包括遥远星系、宇宙再电离以及光学天文前沿观测技术等。