12 papers
Radio Activity Across Accretion State Changes in Changing-look AGNs: Insights from FIRST and VLASS over Two Decades
Zhi-Qiang Chen, Wei-Jian Guo, Victoria A. Fawcett +8
Changing-look active galactic nuclei (CL-AGNs) provide a unique opportunity to probe the coupling between accretion flows and relativistic jets in supermassive black holes. We inve…
Discovery of Repeating Transitions in 16 Changing-look Active Galactic Nuclei
Qian Dong, Zhi-Xiang Zhang, Wei-Min Gu +5
The repeating changing-look active galactic nuclei (RCL AGNs) exhibit multiple appearances and disappearances of broad emission lines (BELs), whose underlying mechanism remains a p…
Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. XV. Reverberation Mapping of Mg II Emission Lines
Hua-Rui Bai, Pu Du, Chen Hu +25
As the 15th paper in a series reporting on a large reverberation mapping (RM) campaign of super-Eddington accreting massive black holes (SEAMBHs) in active galactic nuclei (AGNs),…
Chemical evolution of bulges of active galactic nuclei in the early Universe: roles of accreting stars
Shuo Zhai, Jian-Min Wang, Yan-Rong Li +2
JWST/NIRCam observations reveal dense stellar cores in high-redshift galactic bulges, indicative of sustained star formation and potential stellar accretion. We introduce accretion…
Changing-look Active Galactic Nuclei from the Dark Energy Spectroscopic Instrument. V. Dramatic Variability in High-Ionization Broad Emission Lines
Zhi-Qiang Chen, Jun-Jie Jin, Wei-Jian Guo +10
We present a systematic search for changing-look (CL) quasars at high redshift z > 0.9 by cross-matching the spectroscopic datasets from the Dark Energy Spectroscopic Instrument Da…
Changing-look Active Galactic Nuclei from the Dark Energy Spectroscopic Instrument. IV. Broad Emission Line Evolution Sequence Among Hα, Mg II, and Hβ
Wei-Jian Guo, Victoria A. Fawcett, MaÅgorzata Siudek +15
From a parent catalog of 561 changing-look active galactic nuclei (CL-AGNs) identified by Guo et al. (2025), we investigate the evolutionary sequence of broad emission lines using…