Dynamo processes in accretion disks and applicatio
报告人:
周竑喆博士目前于上海交通大学李政道研究所从事博士后研究工作。他2015年本科毕业于复旦大学，2020年博士毕业于罗切斯特大学。2020-2022年他在北欧理论物理研究所从事博士后研究工作。他主要利用理论和数值模拟研究天体磁流体力学，研究课题包括致密天体附近的吸积流、星系磁场和宇宙原初磁场。摘要:
The UV/optical light curves observed in active galactic nuclei (AGNs) are well-characterized by damped random walk (DRW) process, with the damping timescale exhibiting correlations with both the black hole mass and the photon wavelength. However, the underlying physical origins for the DRW process and the scaling laws remain unclear. We aim to understand the AGN variability induced by a quasi-periodic large-scale dynamo in an accretion disk, and examine whether it reproduces the observed variability features in AGN UV/optical light curves. In this talk, I will first introduce what are dynamos and what are the difficulties in studying dynamos in accretion disks. I will then discuss the current disk dynamo models and connect them to AGN variability.