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Related papers: Active Galactic Nuclei Discovered in the Kepler Mi…

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We present deep Near-infrared (NIR) images of a sample of 19 intermediate-redshift ($0.3<z<1.0$) radio-loud active galactic nuclei (AGN) with powerful relativistic jets ($L_{1.4GHz} >10^{27}$ WHz$^{-1}$), previously classified as…

The detection of quasi-periodic oscillations (QPOs) in the light curves of active galactic nuclei (AGNs) can provide insights into the physics of the super-massive black-holes (SMBHs) powering these systems and could represent a signature…

High Energy Astrophysical Phenomena · Physics 2023-04-05 Helena X. Ren , Matteo Cerruti , Narek Sahakyan

Multi-wavelength observations of active galactic nuclei (AGNs) often reveal various time scales of variability. Among these phenomena, "changing-look AGNs" are extreme cases where broad emission lines become faint/bright or even…

Astrophysics of Galaxies · Physics 2023-09-25 Keiichi Wada , Yuki Kudoh , Tohru Nagao

The evolution of extragalactic radio sources has been a fundamental problem in the study of active galactic nuclei for many years. A standard evolutionary model has been created based on observations of a wide range of radio sources. In the…

Astrophysics of Galaxies · Physics 2017-12-04 Aleksandra Wołowska , Magdalena Kunert-Bajraszewska , Kunal Mooley , Gregg Hallinan

We study the properties of a sample of 211 heavily-obscured Active Galactic Nucleus (AGN) candidates in the Extended Chandra Deep Field-South selecting objects with f_24/f_R>1000 and R-K>4.5. Of these, 18 were detected in X-rays and found…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 E. Treister , C. Cardamone , K. Schawinski , C. M. Urry , E. Gawiser , S. Virani , P. Lira , J. Kartaltepe , M Damen , E. N. Taylor , E. Le Floc'h , Stephen Justham , A. Koekemoer

We present a study of the prevalence and luminosity of Active Galactic Nuclei (AGN; traced by optical spectra) as a function of both environment and galaxy interactions. For this study we used a sample of more than 250000 galaxies drawn…

Astrophysics of Galaxies · Physics 2014-11-20 J. Sabater , P. N. Best , T. M. Heckman

Active galactic nuclei (AGNs) are known to exhibit optical/UV variability and most of them can be well modeled by the damped random walks. Physical processes that are not related to the accretion disk, such as tidal disruption events (TDE)…

Astrophysics of Galaxies · Physics 2024-04-17 Zhiyuan Zheng , Yong Shi , Shuowen Jin , H. Dannerbauer , Qiusheng Gu , Xin Li , Xiaoling Yu

We present a comprehensive study of five nearby active galaxies featuring large (tens of kpc) extended emission-line regions (EELRs). The study is based on large-format integral field spectroscopic observations conducted with the Multi Unit…

Astrophysics of Galaxies · Physics 2025-11-05 C. Finlez , E. Treister , F. Bauer , M. Koss , W. Keel , W. Maksym , L. Sartori , G. Venturi , C. Ricci , N. Nagar , C. Riesco , Y. Díaz , M. Parra

We present new results from the VLBA 2 cm Survey, an imaging survey of active galactic nuclei (AGN) at sub-milliarcsecond resolution. We extend the structural variability monitoring program of more than 130 extragalactic parsec-scale radio…

Astrophysics · Physics 2007-05-23 E. Ros

In this study, we demonstrate some of the caveats in common statistical methods used for analysing astronomical variability timescales. We consider these issues specifically in the context of active galactic nuclei (AGNs) and use a more…

Astrophysics of Galaxies · Physics 2024-12-12 Sofia Kankkunen , Merja Tornikoski , Talvikki Hovatta

Over the last five decades, AGN studies have produced a number of spectacular examples of synergies and multifaceted approaches in astrophysics. The field of AGN research now spans the entire spectral range and covers more than twelve…

Astrophysics · Physics 2015-06-24 Andrei P. Lobanov , J. Anton Zensus

Active Galactic Nuclei (AGN) have long been known to be variable, but the amplitude, timescale and nature of these changes can often differ dramatically from object to object. The richest source of information about the properties of AGN…

Astrophysics of Galaxies · Physics 2021-07-14 Hartmut Winkler

The main fuelling processes for Active Galactic Nuclei (AGN) are currently unknown. Previous work showed that galaxies with a large kinematic misalignment between their stellar and gas reservoirs have a higher AGN fraction than galaxies…

We study the long-term variability in the optical monitoring database of Ark~120, a nearby radio-quiet active galactic nucleus (AGN) at a distance of 143 Mpc (z=0.03271). We compiled the historical archival photometric and spectroscopic…

Active galactic nuclei (AGN) in low surface brightness galaxies (LSBGs) have received little attention in previous studies. In this paper, we present detailed spectral analysis of 194 LSBGs from the Impey et al. (1996) APM LSBG sample which…

Astrophysics of Galaxies · Physics 2009-11-13 Lin Mei , Weimin Yuan , Xiaobo Dong

We probe the feasibility of high-frequency radio observations of very rapid flux variations in compact active galactic nuclei (AGN). Our study assumes observations at 230 GHz with a small 6-meter class observatory, using the SNU Radio…

Astrophysics of Galaxies · Physics 2017-01-18 Jae-Young Kim , Sascha Trippe

We first review some basic properties of the most important classes of active galactic nuclei (AGN), including quasars, blazars, Seyfert galaxies and radio galaxies. The most commonly accepted type of scheme designed to individually unify…

Astrophysics · Physics 2007-05-23 Paul J. Wiita

Determining the frequency and duration of changing--look (CL) active galactic nuclei (AGNs) phenomena, where the optical broad emission lines appear or disappear, is crucial to understand the evolution of the accretion flow around…

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