Lunch talk on Jun. 11, 2025

The outburst phenomena and potential physical mechanisms in the Changing-look AGN

Speaker: Weijian Guo (NAOC)

Venue: SWIFAR Building 2111

Time: 12:45 PM, Wednesday, Jun. 11, 2025

Abstract: 

Changing-Look Active Galactic Nuclei (CL-AGNs) challenge both the standard accretion disk paradigm and the orientation-based AGN unification model. Leveraging the first-year data release from the Dark Energy Spectroscopic Instrument (DESI), we construct the largest CL-AGN sample to date, comprising over 500 candidates, and present the first comprehensive statistical analysis of such a population. We find a strong correlation between the luminosity variations of broad emission lines (BELs) and the continuum. Our analysis suggests that a significant fraction of CL events—particularly those involving changes in only one BEL—may stem from typical AGN variability under low accretion rates, rather than from extreme or external phenomena. In this talk, I will focus on a subclass of CL-AGNs undergoing  multiple outburst and potential physical mechanisms.