56 citations · 160 across the 17 of their papers we have counts for
19 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…
Electromagnetic Flares from Compact-Object Mergers in AGN Disks: Signatures and Predictions
Hiromichi Tagawa, Zoltán Haiman, Shigeo S. Kimura +2
Accretion disks in active galactic nuclei (AGN) are promising sites for mergers of stellar-mass black holes (BHs) detectable via gravitational waves (GWs). These environments facil…
X-ray Quasi-Periodic Oscillations in Active Galactic Nuclei and Their Implications for the Changing Look Phenomenon
Mouyuan Sun, Shuying Zhou, Jihong Liu +12
X-ray timing of active galactic nuclei (AGN) provides a unique probe of gas accretion onto supermassive black holes (SMBHs). Quasi-periodic oscillations (QPOs), which trace gas dyn…
The Intermediate-Mass Black Hole Reverberation Mapping Project: Stable Optical Continuum Lags of an IMBH in the Dwarf Galaxy NGC 4395 Over Years
Yu Pan, Hengxiao Guo, Chenxu Liu +15
NGC 4395 is a nearby dwarf spiral galaxy hosting an active galactic nucleus (AGN) powered by an intermediate-mass black hole (IMBH, --). Re…
Joint Analysis of Optical, Near-Infrared And Mid-Infrared Variability of 4 Quasars at Redshift < 1
Lin Long, Zhen-ya Zheng, Ning Jiang +8
Amid rapid advances in time-domain astronomy, multi-wavelength (e.g., optical and infrared) time-domain studies of quasars remain scarce. Here we present a systematic analysis of f…
Departures from Standard Disk Predictions in Intensive Ground-Based Monitoring of Three AGN
Diego Gonzalez-Buitrago, Aaron J. Barth, Rick Edelson +42
We present ground-based, multi-band light curves of the AGN Mrk~509, NGC\,4151, and NGC\,4593 obtained contemporaneously with \sw\, monitoring. We measure cross-correlation lags re…
Interband Lag Variability in Active Galactic Nuclei across ZTF Data from Multiple Years
Zhen-Bo Su, Zhen-Yi Cai, Hengxiao Guo +2
Interband lags in the optical continua of active galactic nuclei (AGN) have been observed over years of monitoring, yet their physical origins remain unclear. While variable interb…
Dormancy and Reawakening Over Years: Eight New Recurrent Changing-Look AGNs
Shu Wang, Jong-Hak Woo, Elena Gallo +5
We report the discovery of eight new recurrent changing-look (CL) active galactic nuclei (AGNs), including seven re-brightening turn-off AGNs and one fading turn-on AGN. These syst…
Could the inter-band lag of active galactic nucleus vary randomly?
Zhen-Bo Su, Zhen-Yi Cai, Jun-Xian Wang +18
The inter-band lags among the optical broad-band continua of active galactic nuclei (AGNs) have been intensively explored over the past decade. However, the nature of the lags rema…
Unprecedented Continuum Time Delay Variation Phenomenon in an Active Supermassive Black Hole
Shuying Zhou, Mouyuan Sun, Hai-Cheng Feng +12
Resolving the accretion disks and broad line regions (BLRs) of active galactic nuclei (AGNs) can probe the physics behind supermassive black holes (SMBHs) fueling and weigh SMBHs.…
Understanding the Broad-line Region of Active Galactic Nuclei with Photoionization. I. the Moderate-Accretion Regime
Qiaoya Wu, Yue Shen, Hengxiao Guo +9
Over three decades of reverberation mapping (RM) studies on local broad-line active galactic nuclei (AGNs) have measured reliable black-hole (BH) masses for AGNs. These RM…
Prior-Informed AGN-Host Spectral Decomposition Using PyQSOFit
Wenke Ren, Hengxiao Guo, Yue Shen +4
We introduce an improved method for decomposing the emission of active galactic nuclei (AGN) and their host galaxies using templates from principal component analysis (PCA). This a…
A new timescale-mass scaling for the optical variation of active galactic nuclei across the intermediate-mass to supermassive scales
Zhen-Bo Su, Zhen-Yi Cai, Mouyuan Sun +3
Variability of active galactic nuclei (AGNs) has long been servicing as an essential avenue of exploring the accretion physics of black hole (BH). There are two commonly used metho…
Optical Continuum Reverberation Mapping of a Candidate IMBH in a Nearby Seyfert 1 Galaxy
Wenwen Zuo, Hengxiao Guo, Jingbo Sun +25
To investigate the short-term variability and determine the size of the optical continuum emitting region of intermediate-mass black holes (IMBHs), we carried out high-cadence, mul…
Identifying changing-look AGNs using variability characteristics
Shu Wang, Jong-Hak Woo, Elena Gallo +7
Changing-look (CL) Active Galactic Nuclei (AGNs), characterized by appearance/disappearance of broad emission lines in the span of a few years, present a challenge for the AGN unif…
AGN Continuum Reverberation Mapping Based on Zwicky Transient Facility Light Curves
Hengxiao Guo, Aaron J. Barth, Shu Wang
We perform a systematic survey of active galactic nucleus (AGN) continuum lags using 3 day cadence -band light curves from the Zwicky Transient Facility. We select a sam…
Optical Continuum Reverberation in the Dwarf Seyfert Nucleus of NGC 4395
John W. Montano, Hengxiao Guo, Aaron J. Barth +4
The nearby dwarf spiral galaxy NGC 4395 contains a broad-lined active galactic nucleus (AGN) of exceptionally low luminosity powered by accretion onto a central black hole of very…
The Paschen Jump as a Diagnostic of the Diffuse Nebular Continuum Emission in Active Galactic Nuclei
Hengxiao Guo, Aaron J. Barth, Kirk T. Korista +17
Photoionization modeling of active galactic nuclei (AGN) predicts that diffuse continuum (DC) emission from the broad-line region makes a substantial contribution to the total cont…
The optical variability of SDSS quasars from multi-epoch spectroscopy: I. Results from 60 quasars with six-epoch spectra
Hengxiao Guo, Minfeng Gu
In a sample of 60 quasars selected from Sloan Digital Sky Survey (SDSS) with at least six-epoch spectroscopy, we investigate the variability of emission lines and continuum luminos…