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Related papers: Interband Lag Variability in Active Galactic Nucle…

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Continuum reverberation mapping probes the sizescale of the optical continuum-emitting region in active galactic nuclei (AGN). Through 3 years of multiwavelength photometric monitoring in the optical with robotic observatories, we perform…

While 2% of active galactic nuclei (AGNs) exhibit narrow emission lines with line-of-sight velocities that are significantly offset from the velocity of the host galaxy's stars, the nature of these velocity offsets is unknown. We…

Astrophysics of Galaxies · Physics 2017-10-04 Julia M. Comerford , R. Scott Barrows , Jenny E. Greene , David Pooley

Most of the variability studies of active galactic nuclei (AGNs) are based on ensemble analyses. Nevertheless, it is interesting to provide estimates of the individual variability properties of each AGN, in order to relate them with…

Astrophysics of Galaxies · Physics 2020-11-17 M. Laurenti , F. Vagnetti , R. Middei , M. Paolillo

The optical-ultraviolet continuum from active galactic nuclei (AGN) seem to originate from optically thick and/or thin disks, and occasionally from associated circumnuclear starburst regions. These different possible origins can, in…

Astrophysics · Physics 2007-05-23 A. Yonehara , S. Mineshige , J. Fukue , M. Umemura , E. L. Turner

We test the consistency of active galactic nuclei (AGN) optical flux variability with the $\textit{damped random walk}$ (DRW) model. Our sample consists of 20 multi-quarter $\textit{Kepler}$ AGN light curves including both Type 1 and 2…

Astrophysics of Galaxies · Physics 2015-07-03 Vishal P. Kasliwal , Michael S. Vogeley , Gordon T. Richards

The spectral variability of active galactic nuclei (AGN) is one of their key features that enables us to study in more details the structure of AGN emitting regions. Especially, the broad line profiles, that vary both in flux and shape,…

Astrophysics of Galaxies · Physics 2016-01-20 D. Ilic , L. C. Popovic , A. I. Shapovalova , A. N. Burenkov , V. H. Chavushyan , A. Kovacevic

The incidence and properties of Active Galactic Nuclei (AGN) in the field, groups, and clusters can provide new information about how these objects are triggered and fueled, similar to how these environments have been employed to study…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Timothy J. Arnold , Paul Martini , John S. Mulchaey , Angela Berti , Tesla E. Jeltema

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 low mass ($\sim10^4-10^5$ M$_\odot$). In order to constrain…

The All Sky Monitor (ASM) onboard the Rossi X-ray Timing Explorer (RXTE) has continuously monitored a number of Active galactic nuclei (AGNs) with similar sampling rates for 14 years from 1996 January to 2009 December. Utilizing the…

High Energy Astrophysical Phenomena · Physics 2015-05-20 You-Hong Zhang

We present infrared, optical, and X-ray data of 48 X-ray bright, optically dull AGNs in the COSMOS field. These objects exhibit the X-ray luminosity of an active galactic nucleus (AGN) but lack broad and narrow emission lines in their…

Active Galactic Nuclei (AGNs) are among the most luminous objects in the universe, making them valuable probes for studying galaxy evolution. However, understanding how AGN properties evolve over cosmic time remains a fundamental challenge.…

Astrophysics of Galaxies · Physics 2025-05-06 Shreya Sareen , Swayamtrupta Panda

We report on candidate active galactic nuclei (AGN) discovered during the monitoring of $\sim$500 bright (r < 18 mag) galaxies over several years with the Kepler Mission. Most of the targets were sampled every 30 minutes nearly continuously…

High Energy Astrophysical Phenomena · Physics 2015-12-09 Edward J. Shaya , Robert Olling , Richard Mushotzky

The changing-look active galactic nucleus (CL-AGN), an extraordinary subpopulation of supermassive black holes, has attracted growing attention for understanding its nature. We present an analysis of the spectral properties of 203…

Astrophysics of Galaxies · Physics 2025-10-13 Yu-Heng Shen , Kai-Xing Lu , Wei-Jian Guo , Sha-Sha Li , Hai-Cheng Feng , Zhang Yue , Wen-Zhe Xi , Jian-Guo Wang , Jin-Ming Bai

Active Galactic Nuclei (AGN) are highly energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, which present unique observational signatures covering the full electromagnetic spectrum (and more) over…

High Energy Astrophysical Phenomena · Physics 2023-04-05 Stefano Bianchi , Vincenzo Mainieri , Paolo Padovani

We are conducting an archival Swift program to measure multiwavelength variability in active galactic nuclei (AGN). This variability information will provide constraints on the geometry, physical conditions and processes of the structures…

High Energy Astrophysical Phenomena · Physics 2015-05-21 Jonathan Gelbord , Caryl Gronwall , Dirk Grupe , Dan Vanden Berk , Jian Wu

Active Galactic Nuclei (AGN) are axisymmetric systems to first order; their observed properties are likely strong functions of inclination with respect to our line of sight, yet the specific inclinations of all but a few AGN are generally…

Astrophysics of Galaxies · Physics 2015-06-18 T. C. Fischer , D. M. Crenshaw , S. B. Kraemer , H. R. Schmitt , T. J. Turner

We perform a systematic survey of active galactic nucleus (AGN) continuum lags using $\sim$3 day cadence $gri$-band light curves from the Zwicky Transient Facility. We select a sample of 94 type 1 AGN at $z<0.8$ with significant and…

Astrophysics of Galaxies · Physics 2022-11-30 Hengxiao Guo , Aaron J. Barth , Shu Wang

We study the ensemble X-ray variability properties of Active Galactic Nuclei (AGN) over a large range of timescales (20 ks $\leq T\leq$ 14 yrs), redshift ($0\leq z \lesssim 3$), luminosities ($10^{40}$ erg s$^{-1}\leq L_X\leq 10^{46}$ erg…

High Energy Astrophysical Phenomena · Physics 2023-05-10 M. Paolillo , I. E. Papadakis , W. N. Brandt , F. E. Bauer , G. Lanzuisi , V. Allevato , O. Shemmer , X. C. Zheng , D. De Cicco , R. Gilli , B. Luo , M. Thomas , P. Tozzi , F. Vito , Y. Q. Xue

Temporal analysis of X-ray binaries and Active Galactic Nuclei have shown that hard X-rays react to variation of soft ones after a time delay. The opposite trend, or soft lag, has only been seen in a few rare Quasi-periodic Oscillations in…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Shruti Tripathi , Ranjeev Misra , Gulab Dewangan , Shantanu Rastogi

We analyze the broadband photometric light curves of Seyfert 1 galaxies from the Sergeev et al. (2005) sample and find that a) perturbations propagating across the continuum emitting region are a general phenomenon securely detected in most…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Doron Chelouche