7 papers
Fast Optical Variability of the TeV Blazar PKS 1725+123 Observed by SVOM-VT and Insights from Multi-wavelength Follow-up Observations
Shuo-Yu Liu, Yu-Wei Yu, Ji-Shun Lian +29
PKS 1725+123 is a flat-spectrum radio quasar (FSRQ) with a redshift of . The detection of this object in the TeV band was reported by the MAGIC telescopes and H.E.S.S. in…
OQ~208: A New Fe~II Changing-look Active Galactic Nucleus and Implications for the Nature of the Changing-look Phenomenon
J. Wang, W. K. Zheng, D. W. Xu +5
In addition to the traditional hydrogen Balmer emission lines, here we extend the optical changing-look (CL) phenomenon occurring in some active galactic nuclei (AGNs) to the optic…
AGN STORM 2. XII. Ground-Based Optical Photometry and Lag Measurements of Mrk 817
John W. Montano, Aaron J. Barth, Keith Horne +40
We present the ground-based imaging campaign and light curves of Markarian 817 as part of the multiwavelength monitoring program AGN STORM\,2. Observations were carried out over 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),…
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…
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…