45 citations · 106 across the 22 of their papers we have counts for
23 papers
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.…
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),…
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…
Little red dots as embryos of active galactic nuclei
Jian-Min Wang, Yi-Lin Wang, Yong-Jie Chen +7
As an unprecedented large population in the early universe, the JWST-discovered little red dots (LRDs) have garnered much attention for formation of massive black holes and galaxie…
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…
A Systematic Search for Active Galactic Nucleus Flares in ZTF Data Release 23
Lei He, Zheng-Yan Liu, Rui Niu +13
Active galactic nuclei (AGNs) are known to exhibit stochastic variability across a wide range of timescales and wavelengths. AGN flares are extreme outbursts that deviate from this…
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…
Monitoring AGNs with H Asymmetry. V. Long-term Variation and Evolution of the Broad H Emission-Line Profiles
Feng-Na Fang, Pu Du, Michael S. Brotherton +40
The physical origins of the diverse emission-line asymmetries observed in the spectra of active galactic nuclei (AGNs) remain incompletely understood. Monitoring the temporal varia…
Spectroastrometry and Reverberation Mapping of Active Galactic Nuclei. II. Measuring Geometric Distances and Black Hole Masses of Four Nearby Quasars
Yan-Rong Li, Jinyi Shangguan, Jian-Min Wang +35
The geometric distances of active galactic nuclei (AGNs) are challenging to measure because of their exceptionally compact structure yet vast cosmic distances. A combination of spe…
B2 1308+326: a changing-look blazar or not?
Ashwani Pandey, Chen Hu, Jian-Min Wang +6
In our previous study, we identified a shift in the synchrotron peak frequency of the blazar B2 1308326 from 10 Hz to 10 Hz during a flare, suggesting it could…
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 $…
Spectroastrometry and Reverberation Mapping (SARM) of Active Galactic Nuclei. I. The H Broad-line Region Structure and Black Hole Mass of Five Quasars
Yan-Rong Li, Chen Hu, Zhu-Heng Yao +18
We conduct a reverberation mapping (RM) campaign to spectroscopically monitor a sample of selected bright active galactic nuclei with large anticipated broad-line region (BLR) size…
Monitoring AGNs with H Asymmetry. IV. First Reverberation Mapping Results of 14 AGNs
T. E. Zastrocky, Michael S. Brotherton, Pu Du +41
We report first-time reverberation mapping results for 14 AGNs from the ongoing Monitoring AGNs with H Asymmetry campaign (MAHA). These results utilize optical spectra obtained…
Star Formation in Self-gravitating Disks in Active Galactic Nuclei. III. Efficient Production of Iron and Infrared Spectral Energy Distributions
J. -M. Wang, S., Zhai +7
Strong iron lines are a common feature of the optical spectra of active galactic nuclei (AGNs) and quasars from to the local Universe, and [Fe/Mg] ratios do not show co…
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…
Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. XIII. Ultraviolet Time Lag of H Emission in Mrk 142
V. C. Khatu, S. C. Gallagher, K. Horne +17
We performed a rigorous reverberation-mapping analysis of the broad-line region (BLR) in a highly accreting () active galactic nucleus, Markarian 142 (…
Revisiting Emission-Line Measurement Methods for Narrow-Line Active Galactic Nuclei
Viraja C. Khatu, Sarah C. Gallagher, Keith Horne +16
Measuring broad emission-line widths in active galactic nuclei (AGN) is not straightforward owing to the complex nature of flux variability in these systems. Line-width measurement…
Broad-line region in NGC 4151 monitored by two decades of reverberation mapping campaigns. I. Evolution of structure and kinematics
Yong-Jie Chen, Dong-Wei Bao, Shuo Zhai +33
We report the results of long-term reverberation mapping (RM) campaigns of the nearby active galactic nuclei (AGN) NGC 4151, spanning from 1994 to 2022, based on archived observati…
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…
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…
AGN STORM 2: I. First results: A Change in the Weather of Mrk 817
Erin Kara, Missagh Mehdipour, Gerard A. Kriss +69
We present the first results from the ongoing, intensive, multi-wavelength monitoring program of the luminous Seyfert 1 galaxy Mrk 817. While this AGN was, in part, selected for it…