45 citations · 120 across the 17 of their papers we have counts for
22 papers
A Decade-Scale Ionization Echo of Black-Hole Accretion in Galactic Nuclei
Wei-Jian Guo, Shuo Zhai, Chen Hu +16
Circumnuclear structures in active galactic nuclei respond to accretion variability over different spatial and temporal scales, but whether compact narrow-line gas responds on deca…
Changing-look Active Galactic Nuclei from the Dark Energy Spectroscopic Instrument. VII. Testing Disk-Corona Diagnostics with eROSITA
Wei-Jian Guo, Shuo Zhai, Zhu-Heng Yao +3
Changing-look active galactic nuclei (CL-AGN) have been proposed to follow an X-ray-binary-like, V-shaped relation between the optical/ultraviolet-to-X-ray spectral slope, $α_{\rm…
Nitrogen-Loud Quasars from the Dark Energy Spectroscopic Instrument. I. Sample Selection and Basic Properties
Shuo Zhai, Wei-Jian Guo, Yong-Jie Chen +4
We present the largest sample to date of nitrogen-loud (N-loud) quasars with strong broad N IV] and/or N III] emission lines over the redshift range $1.…
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…
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, Małgorzata 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…
Detection of unexpected leading delays in broad Hβ line reverberations in the quasar PHL 1092
Jian-Min Wang, Chen Hu, Yong-Jie Chen +12
Delayed reverberations of broad emission lines in response to optical continuum variations have been widely observed in active galactic nuclei (AGNs). They serve as a powerful tool…
Accretion-Regulated Type Transitions in Changing-Look AGNs: Evidence from Two-Epoch Spectral Analysis
Yu-Heng Shen, Kai-Xing Lu, Wei-Jian Guo +6
The changing-look active galactic nucleus (CL-AGN), an extraordinary subpopulation of supermassive black holes, has attracted growing attention for understanding its nature. We pre…
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. XIV. Long-Duration High-Cadence Reverberation Mapping Results for 11 PG Quasars
Chen Hu, Zhu-Heng Yao, Yong-Jie Chen +20
We report the results of a long-duration high-cadence reverberation mapping campaign of a second batch of 11 PG quasars using the 2.2m telescope at the Calar Alto Observatory. This…
A Short-lived Rejuvenation during the Decades-long Changing-look Transition in the Nucleus of Mrk 1018
Kai-Xing Lu, Yan-Rong Li, Qingwen Wu +13
Changing-look active galactic nuclei (CL-AGNs), characterized by emerging or disappearing of broad lines accompanied with extreme continuum flux variability, have drawn much attent…
Broad-line Region of the Quasar PG 2130+099. II. Doubling the Size Over Four Years?
Zhu-Heng Yao, Sen Yang, Wei-Jian Guo +16
Over the past three decades, multiple reverberation mapping (RM) campaigns conducted for the quasar PG 2130+099 have exhibited inconsistent findings with time delays ranging from $…
Gleeok's Fire-breathing: Triple Flares of AT 2021aeuk within Five Years from the Active Galaxy SDSS J161259.83+421940.3
Dong-Wei Bao, Wei-Jian Guo, Zhi-Xiang Zhang +12
We present a noteworthy transient AT 2021aeuk exhibiting three distinct optical flares between 2018 and 2023. It is hosted in a radio-loud narrow-line Seyfert 1 (NLSy1) galaxy, wit…
Strong [O III] λ5007 Compact Galaxies Identified from SDSS DR16 and Their Scaling Relations
Weiyu Ding, Hu Zou, Xu Kong +11
Green pea galaxies are a special class of star-forming compact galaxies with strong [O III]λ5007 and considered as analogs of high-redshift Lyα-emitting galaxies and potential sour…
Changing-look Active Galactic Nuclei from the Dark Energy Spectroscopic Instrument. I.Sample from the Early Data
Wei-Jian Guo, Hu Zou, Victoria Anne Fawcett +34
Changing-look Active Galactic Nuclei (CL AGN) can be generally confirmed by the emergence (turn-on) or disappearance (turn-off) of broad emission lines, associated with a transient…
Testing Super-Eddington Accretion onto a Supermassive Black Hole: Reverberation Mapping of PG 1119+120
Fergus R. Donnan, Juan V. Hernández Santisteban, Keith Horne +11
We measure the black hole mass and investigate the accretion flow around the local () quasar PG 1119+120. Spectroscopic monitoring with Calar Alto provides H lags and…
Monitoring AGNs with H Asymmetry. III. Long-term Reverberation Mapping Results of 15 Palomar-Green Quasars
Dong-Wei Bao, Michael S. Brotherton, Pu Du +42
In this third paper of the series reporting on the reverberation mapping (RM) campaign of active galactic nuclei with asymmetric H emission-line profiles, we present results for…
Searching for quasar candidates with periodic variations from the Zwicky Transient Facility: results and implications
Yong-Jie Chen, Shuo Zhai, Jun-Rong Liu +7
We conduct a systematic search for quasars with periodic variations from the archival photometric data of the Zwicky Transient Facility by cross-matching with the quasar catalogs o…
Accretion Disk Size Measurements of Active Galactic Nuclei Monitored by the Zwicky Transient Facility
Wei-Jian Guo, Yan-Rong Li, Zhi-Xiang Zhang +2
We compile a sample of 92 active galactic nuclei (AGNs) at z<0.75 with photometric light curves from the archival data of the Zwicky Transient Facility and measure the accret…
Reverberation Mapping of Two Luminous Quasars: the Broad-line Region Structure and Black Hole Mass
Sha-Sha Li, Sen Yang, Zi-Xu Yang +21
We report the results of a multi-year spectroscopic and photometric monitoring campaign of two luminous quasars, PG~0923+201 and PG~1001+291, both located at the high-luminosity en…