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An essential part of the paradigm describing active galactic nuclei is the alignment between the radio jet and the associated rotation axis of the sub-pc sized accretion disks. Because of the small linear and angular scales involved, this…

We compile a sample of 92 active galactic nuclei (AGNs) at z<0.75 with $gri$ photometric light curves from the archival data of the Zwicky Transient Facility and measure the accretion disk sizes via continuum reverberation mapping. We…

Astrophysics of Galaxies · Physics 2022-04-20 Wei-Jian Guo , Yan-Rong Li , Zhi-Xiang Zhang , Luis C. Ho , Jian-Min Wang

Despite many decades of study, the kinematics of the broad-line region of 3C~273 are still poorly understood. We report a new, high signal-to-noise, reverberation mapping campaign carried out from November 2008 to March 2018 that allows the…

We present the results of photometric reverberation mapping observations on the changing look active galactic nucleus Mrk 590 at z = 0.026. The observations were carried out from July to December, 2018 using broad band B, R and narrow band…

Intensive broadband reverberation mapping campaigns have shown that AGN variability is significantly more complex than expected from disc reverberation of the variable X-ray illumination. The UV/optical variability is highly correlated and…

High Energy Astrophysical Phenomena · Physics 2024-05-02 Scott Hagen , Chris Done , Rick Edelson

We present an improved and expanded simply parameterized phenomenological model of the broad line region (BLR) in active galactic nuclei (AGN) for modeling reverberation mapping data. By modeling reverberation mapping data directly, we can…

Astrophysics of Galaxies · Physics 2015-06-22 Anna Pancoast , Brendon J. Brewer , Tommaso Treu

AGN reverberate when the broad emission lines respond to changes of the ionizing thermal continuum emission. Reverberation measurements have been commonly used to estimate the size of the broad-line region (BLR) and the mass of the central…

High Energy Astrophysical Phenomena · Physics 2014-11-04 J. León-Tavares , V. Chavushyan , A. Lobanov , E. Valtaoja , T. G. Arshakian

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 methods for analyzing AGN variability. First, the AGN…

Astrophysics of Galaxies · Physics 2024-07-04 Zhen-Bo Su , Zhen-Yi Cai , Mouyuan Sun , Hengxiao Guo , Wei-Min Gu , Jun-Xian Wang

We present the results of a nearly decade-long photometric reverberation mapping (PRM) survey of the H$\alpha$ emission line in nearby ($0.01\lesssim z \lesssim0.05$) Seyfert-Galaxies using small ($15\,\mathrm{cm}-40\,\mathrm{cm}$)…

Mass estimates of black holes (BHs) in the centers of Active Galactic Nuclei (AGN) often rely on the radius-luminosity relation. However, this relation, usually probed by reverberation mapping (RM), is poorly constrained in the…

We apply a new method of determination of the size of the broad emission-line region (BLR) in active galactic nuclei. This method relates the radius of the broad-line region of AGN to the soft X-ray luminosity and spectral index. Comparing…

Astrophysics · Physics 2016-01-27 Amri Wandel , Thomas Boller

We present preliminary results of a study of the low frequency radio continuum emission from the nuclei of Giant Low Surface Brightness (LSB) galaxies. We have mapped the emission and searched for extended features such as radio lobes/jets…

Astrophysics · Physics 2009-11-13 M. Das , S. S. McGaugh , N. Kantharia , S. N. Vogel

Graham et al. found a sample of active galactic nuclei (AGNs) and quasars from the Catalina Real-time Transient Survey (CRTS) that have long-term periodic variations in optical continuum, the nature of the periodicity remains uncertain. We…

Astrophysics of Galaxies · Physics 2016-04-20 Kai-Xing Lu , Yan-Rong Li , Shao-Lan Bi , Jian-Min Wang

We present radio observations and optical spectroscopy of the giant low surface brightness (LSB) galaxy PGC 045080 (or 1300+0144). PGC 045080 is a moderately distant galaxy having a highly inclined optical disk and massive HI gas content.…

Astrophysics · Physics 2009-06-23 M. Das , N. Kantharia , S. Ramya , T. P. Prabhu , S. S. McGaugh , S. N. Vogel

We present dynamical modeling of the broad line region (BLR) for a sample of five Seyfert 1 galaxies using reverberation mapping data taken by the Lick AGN Monitoring Project in 2008. By modeling the AGN continuum light curve and H$\beta$…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Anna Pancoast , Brendon J. Brewer , Tommaso Treu , Daeseong Park , Aaron J. Barth , Misty C. Bentz , Jong-Hak Woo

In the sixth of the series of papers reporting on a large reverberation mapping (RM) campaign of active galactic nuclei (AGNs) with high accretion rates, we present velocity-resolved time lags of H$\beta$ emission lines for nine objects…

Astrophysics of Galaxies · Physics 2016-03-23 Pu Du , Kai-Xing Lu , Chen Hu , Jie Qiu , Yan-Rong Li , Ying-Ke Huang , Fang Wang , Jin-Ming Bai , Wei-Hao Bian , Ye-Fei Yuan , Luis C. Ho , Jian-Min Wang

We conducted an analysis of gamma-ray variability in a large sample of jetted active galactic nuclei (AGNs) by utilizing archival Fermi-LAT light curves and applying damped random walk modeling to obtain variability amplitude. Our primary…

High Energy Astrophysical Phenomena · Physics 2026-05-21 Yongyun Chen , Qiusheng Gu , Junhui Fan , Dingrong Xiong , Xiaoling Yu , Xiaogu Zhong , Xiaotong Guo , Nan Ding

Accreting black holes are thought to swallow matter in the form of a disk and a hot cloud of plasma that glows brightly in X-rays, known as the corona. The X-ray emitting region is far too small to be directly imaged, but rapid variability…

High Energy Astrophysical Phenomena · Physics 2026-04-02 Bei You , Wei Yu , Adam Ingram , Barbara De Marco , Jin-Lu Qu , Zong-Hong Zhu , Andrea Santangelo , Sai-En Xu

We calculate the diffuse $\gamma$-ray emission due to the population of misaligned AGN (MAGN) unresolved by the Large Area Telescope (LAT) on the {\it Fermi} Gamma-ray Space Telescope ({\it Fermi}). A correlation between the $\gamma$-ray…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-21 M. Di Mauro , F. Donato , F. Calore