云南大学中国西南天文研究所

 首页 Home | 研究所简介 SWIFAR | 人员 People | 科学研究 Science | 科研设备 Facilities | 学术活动 Activities | 人才培养 Education | 国际合作 Collaborations | 科学普及 Outreach | 诚聘英才 Recruitment | 访问指南 For Visitors 
 
 首页 Home 
 研究所简介 SWIFAR 
 人员 People 
 科学研究 Science 
 学术活动 Activities 
 人才培养 Education 
 科学普及 Outreach 
 诚聘英才 Recruitment 
 访问指南 For Visitors 
 内部链接 Internal 
 
  过往活动 Past Events
当前位置: 首页 Home>>过往活动 Past Events>>正文
 

Lunch talk on Apr. 19, 2021

The Accretion Disk-Corona Systems in Super-Eddington Accreting AGNs


Speaker: Hezhen Liu (NJU)

Venue: Video conference

Time: 12:30 PM, Monday, Apr. 19, 2021

Abstract: 

Active galactic nuclei (AGNs) are powered by accretion onto central supermassive black holes (SMBHs), during which the gravitational potential energy of gas is converted to strong electromagnetic radiation. A considerable fraction of the energy is emitted in the X-ray band, generated from the hot accretion-disk corona surrounding the SMBHs. Although X-ray emission is a universal property of AGNs, our research group has found a small number of AGNs exhibiting weak X-ray emission compared to the expectation from their UV/optical emission. Some of them sometimes return to high states with nominal X-ray fluxes, thus showing extreme X-ray variability. These phenomena suggest possible unusual physical processes in the central engine or obscuration of X-ray emission by the surrounding medium in these AGNs, probably related to an unusual accretion process (e.g., super-Eddington accretion). In order to explore if super-Eddington accreting AGNs show unusual properties in terms of the X-ray coronae and accretion disk-corona connections, we investigate systematically for the first time the X-ray and multiwavelength properties of an AGN sample with reverberation-mapping measurements that provide relatively accurate SMBH-mass and accretion-rate measurements. I will present in this talk the results of this study and the implications.


Report PPT:  SWIFAR_Hezhen Liu.pdf


附件【SWIFAR_Hezhen Liu.pdf已下载
关闭窗口

版权所有:云南大学中国西南天文研究所 

South-Western Institute For Astronomy Research, YNU