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Related papers: Interband Lag Variability in Active Galactic Nucle…

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Here we investigate light curves of the continuum and emission lines of five type 1 active galactic nuclei (AGN) from our monitoring campaign, to test time-evolution of their time delays.Using both modeled and observed AGN light curves we…

Active Galactic Nuclei (AGN) are known to show flux variability over all observable timescales and across the entire electromagnetic spectrum. Over the past decade, a growing number of sources have been observed to show dramatic flux and…

Astrophysics of Galaxies · Physics 2022-11-11 Claudio Ricci , Benny Trakhtenbrot

Variability detected in galaxies is usually attributed to their active galactic nuclei (AGNs). While all AGNs are intrinsically variable, the AGN unification model predicts that type~2 AGNs rarely vary because their engines are blocked by…

Astrophysics of Galaxies · Physics 2026-02-17 Bangzheng Sun , Haojing Yan , Wei Leong Tee , Feige Wang

Context. A defining characteristic of active galactic nuclei (AGN) that distinguishes them from other astronomical sources is their stochastic variability, which is observable across the entire electromagnetic spectrum. Upcoming optical…

Disk continuum reverberation mapping is one of the primary ways we learn about active galactic nuclei (AGN) accretion disks. Reverberation mapping assumes that time-varying X-rays incident on the accretion disk drive variability in…

High Energy Astrophysical Phenomena · Physics 2025-01-14 Amy Secunda , Yan-Fei Jiang , Jenny E. Greene

Light-travel-time delays provide one of the most powerful ways of learning about the structure and kinematics of active galactic nuclei (AGNs). Estimating delays from observations of AGN variability presents statistical challenges because…

Astrophysics of Galaxies · Physics 2025-01-23 C. Martin Gaskell

There is increasing evidence to suggest that AGN activity may be episodic, with a wide range of possible time scales. Radio galaxies exhibit the most striking examples of episodic activity, with two or three distinct pairs of lobes on…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 D. J. Saikia , M. Jamrozy , C. Konar , S. Nandi

Over the next ten years, the Vera C.\ Rubin Observatory (VRO) will observe $\sim$10 million active galactic nuclei (AGN) with a regular and high cadence. During this time, the intensities of most of these AGN will fluctuate stochastically.…

Astrophysics of Galaxies · Physics 2022-12-20 Cyril Creque-Sarbinowski , Marc Kamionkowski , Bei Zhou

The cosmological evolution of X-ray-selected and optically selected Active Galactic Nuclei (AGNs) show different behaviours interpreted in terms of two different populations. The difference is evident mainly for low luminosity AGNs…

Astrophysics · Physics 2009-11-13 D. Trevese , V. Zitelli , F. Vagnetti , K. Boutsia , G. M. Stirpe

X-ray observations of active galactic nuclei (AGN) show variability on timescales ranging from a few hours up to a few days. Some of this variability may be associated with occultation events by clouds in the broad line region. In this…

High Energy Astrophysical Phenomena · Physics 2018-08-08 E. S. Kammoun , F. Marin , M. Dovciak , E. Nardini , G. Risaliti , M. Sanfrutos

Emission from active galactic nuclei (AGNs) is known to play an important role in the evolution of many galaxies including luminous and ultraluminous systems (U/LIRGs), as well as merging systems. However, the extent, duration, and exact…

We conduct an analysis of over 60,000 dwarf galaxies (7<=log(M_*/M_\odot)<=10) in search of photometric variability indicative of active galactic nuclei (AGNs). Using data from the Young Supernova Experiment (YSE), a time domain survey on…

Some progress in understanding AGN variability is reviewed. Reprocessing of X-ray radiation to produce significant amounts of longer-wavelength continua seems to be ruled out. In some objects where there has been correlated X-ray and…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-27 C. Martin Gaskell , Elizabeth S. Klimek

We investigate the effects of Active Galactic Nuclei (AGN) on the gas kinematics of their host galaxies, using MaNGA data for a sample of 62 AGN hosts and 109 control galaxies (inactive galaxies). We compare orientation of the line of nodes…

The spectra of Active Galactic Nuclei (AGNs) are often characterized by a wealth of emission lines with different profiles and intensity ratios that led to a complicated classification. Their electro-magnetic radiation spans more than 10…

Axion-like particles (ALPs) are compelling candidates for dark matter and potential portals to new physics beyond the Standard Model. Photons traversing magnetized regions can convert into ALPs, producing characteristic, energy-dependent…

High Energy Astrophysical Phenomena · Physics 2026-01-23 Denys Malyshev , Lidiia Zadorozhna , Yuriy Bidasyuk , Andrea Santangelo , Oleg Ruchayskiy

In a previous paper, we studied two statistical methods used to analyse the variability of active galactic nuclei (AGNs): the C and F statistics. Applying them to observed differential light-curves of 39 AGNs, we found that, even though the…

Astrophysics of Galaxies · Physics 2020-09-02 L. Zibecchi , I. Andruchow , S. A. Cellone , D. D. Carpintero

The high quality light curves of Kepler space telescope make it possible to analyze the optical variability of AGNs with an unprecedented time resolution. Studying the asymmetry in variations could give independent constraints on the…

Astrophysics of Galaxies · Physics 2015-05-25 Xiao-Yang Chen , Jun-Xian Wang

We present a comprehensive analysis of the X-ray spectral properties of 198 newly identified active galactic nuclei (AGNs), leveraging archival data from the {\it Chandra} X-ray Observatory. All these AGNs exhibit a powerlaw spectral…

High Energy Astrophysical Phenomena · Physics 2024-10-08 Samrat Ghosh , Samir Mandal , Sudip Bhattacharyya , Shivam Kumaran

Changing-look active galactic nuclei (CLAGNs) show the appearance and disappearance of broad emission lines in their UV/optical spectra on timescales of months to decades. Here, we investigate how CL transitions depend on several AGN…

Astrophysics of Galaxies · Physics 2025-01-08 A. Jana , C. Ricci , M. J. Temple , H. -K. Chang , E. Shablovinskaya , B. Trakhtenbrot , Y. Diaz , D. Ilic , P. Nandi , M. Koss
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