Prof. Chris Reynolds (University of Cambridge)
"Why do accreting black hole vary?"
時間/地點： 2021-05-26 20:00 [Zoom]
摘要：
One of the basic characteristics of an accreting black hole, or indeed any system with an accretion disk, is that the observed luminosity is time variable. However, the basic physics underlying this variability has been uncertain. In this talk I will describe the observed characteristics of the variability and discuss commonalities between accreting black holes and other (very different) accreting systems. I will discuss a set of magnetohydrodynamic (MHD) simulations that have allowed us to reproduce much of the observed behaviour and, in the process, highlight the importance of quasi-periodic dynamo activity that is emergent from the MHD turbulence in the disk. This leads to a first principles understanding of the power-spectral density of the variability, a result than can be utilized in future studies of active galactic nuclei (AGN) with the next generation survey telescopes.
Join Zoom meeting:
https://zoomtw.zoom.us/j/5419957689?pwd=WlB0eDIrcE0wb284Qm13Mm94MG1mUT09
Zoom meeting password: delta