Title: Ultra-fast outflows around highly-accreting supermassive black holes

Speaker: 许叶融

Institute: 意大利国家天体物理研究所-巴勒莫分所 / 巴勒莫大学

Host: 方陶陶

Time: 2024.7.4 周四 16:00

Location: 物理楼 223

Abstract:

Ultra-fast outflows (UFOs) are an extreme subclass of winds in active galactic nuclei (AGN), with mildly relativistic speeds and high ionization states. They are considered one of the most promising candidates for driving AGN feedback, which may affect the evolution of the host galaxies and regulate the growth of supermassive black holes (SMBHs). However, there are still several open questions on UFOs by far: 1) Which kind of launching mechanism can accelerate winds up to relativistic speeds? 2) What is the structure of ionized winds in AGN? 3) Are UFOs powerful enough to drive AGN feedback? 4) Is there any connection between inner accretion flow and UFOs? I will review the state-of-art progress in these questions, present our answers from high-resolution spectroscopy of sub- and super-Eddington AGN, and show how XRISM and NewATHENA will revolutionize the field through ad-hoc simulations.

Bio：

Yerong Xu recently earned his PhD degree from the University of Palermo and the National Institute of Astrophysics (INAF-IASF Palermo) in Italy. He received his Master's degree from the University of Chicago in 2020 and his Bachelor's degree from Fudan University in 2019. He was a European Space Agency (ESA) archival research visitor at Madrid in 2022 and an Erasmus+ visitor at Massachusetts Institute of Technology in 2023. His research interests focus on the X-ray view of active galactic nuclei (AGN) feedback, including accretion and ejection.