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Related papers: Variability-selected low luminosity AGNs in the SA…

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We analyze Hubble Space Telescope (HST) optical imaging of eight low-mass galaxies hosting active galactic nuclei (AGN) identified via their photometric variability in \cite{baldassare_search_2020}. We use GALFIT to model the 2D galaxy…

Astrophysics of Galaxies · Physics 2025-02-06 Erin Kimbro , Vivienne Baldassare , Guy Worthey , Marla Geha , Jenny Greene

I give a brief review of the observational properties of low-luminosity AGNs (LLAGNs). I outline some unresolved issues in the study of LLAGNs, emphasizing the uncertainties in the role of the truncated thin accretion disk, the dusty…

High Energy Astrophysical Phenomena · Physics 2013-02-05 Rodrigo Nemmen

Changing-look active galactic nuclei (CLAGNs) are a unique population of AGNs that exhibit the appearance (turn-on) or disappearance (turn-off) of broad emission lines. This study aims to explore the intrinsic mechanisms of CLAGNs by…

Astrophysics of Galaxies · Physics 2025-11-14 Huimei Wang , Xue-Bing Wu , Nanyu Yao , Bing Lyu , Yuxuan Pang , Yuming Fu , Rui Zhu , Qian Yang

We investigate the use of optical variability to identify and study Active Galactic Nuclei (AGN) in the GOODS-South field. A sample of 22 mid-infrared power law sources and 102 X-ray sources with optical counterparts in the HST ACS images…

Astrophysics · Physics 2009-06-23 Alison Klesman , Vicki Sarajedini

Active galactic nuclei (AGN) are variable on a wide range of timescales, though relatively few systematic variability surveys have been conducted. Previous broad-band (both spectral and temporal) variability surveys of AGN are limited in…

Astrophysics · Physics 2007-05-23 Jonathan E. Grindlay

The origin of the optical flux variability in active galactic nuclei (AGN) is largely unknown. Previous studies have correlated features of the variability structure function (SF) with AGN properties, though they mostly involved…

Astrophysics of Galaxies · Physics 2026-05-06 Ashley Hai Tung Tan , Christian Wolf , Neelesh Amrutha , Christopher A. Onken , John L. Tonry , Rachel Webster

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

Variability is a property shared by practically all AGN. This makes variability selection a possible technique for identifying AGN. Given that variability selection makes no prior assumption about spectral properties, it is a powerful…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Carolin Villforth , Anton M. Koekemoer , Norman A. Grogin

One of the most peculiar characteristics of Active Galactic Nuclei (AGN) is their variability over all wavelengths. This property has been used in the past to select AGN samples and is foreseen to be one of the detection techniques applied…

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…

We study the properties of 975 active galactic nuclei (AGN) selected by variability in the Pan-STARRS1 Medium-Deep Survey. Using complementary multi wavelength data from the ultraviolet to the far-infrared, we use SED fitting to determine…

Astrophysics of Galaxies · Physics 2016-07-27 S. Heinis , S. Gezari , S. Kumar , W. S. Burgett , H. Flewelling , M. E. Huber , N. Kaiser , R. J. Wainscoat , C. Waters

We present the properties of active galactic nuclei (AGN) selected by optical variability in the Subaru/XMM-Newton Deep Field (SXDF). Based on the locations of variable components and light curves, 211 optically variable AGN were reliably…

This article focuses on certain variability and emission characteristics of Active Galactic Nuclei (AGN), especially their radio-loud subset consisting of quasars, BL Lacs and $\gamma$-ray detected narrow-line Seyfert 1 galaxies, all of…

Astrophysics of Galaxies · Physics 2019-06-28 Gopal-Krishna , Silke Britzen , Paul Wiita

This study explores the space density and properties of active galaxies to z=0.8. We have investigated the frequency and nature of unresolved nuclei in galaxies at moderate redshift as indicators of nuclear activity such as Active Galactic…

The morphological study is crucial to investigate the connections between active galactic nuclei (AGN) activities and the evolution of galaxies. Substantial studies have found that radiative-mode AGNs primarily reside in disk galaxies,…

Astrophysics of Galaxies · Physics 2022-02-09 Yuxing Zhong , Akio K. Inoue , Satoshi Yamanaka , Toru Yamada

The high-redshift ($z>4$) compact sources with ``V-shaped" spectral energy distributions (SEDs), known as Little Red Dots (LRDs), are discovered by the James Webb Space Telescope and provide valuable clues to the physics of active galactic…

Astrophysics of Galaxies · Physics 2025-08-26 Shuying Zhou , Mouyuan Sun , Zijian Zhang , Jie Chen , Luis C. Ho

Active Galactic Nuclei (AGN) sources feature supermassive black holes that launch relativistic plasma jets. They are key $\gamma$-ray sources providing a unique laboratory for studying extreme particle acceleration and plasma physics.…

High Energy Astrophysical Phenomena · Physics 2026-02-03 Luana Passos-Reis , Elisabete M. de Gouveia Dal Pino , Tarek Hassan , Santiago Pita , Alberto Domínguez

Variability is a general property of active galactic nuclei (AGN). At X-rays, the way in which these changes occur is not yet clear. In the particular case of low ionisation nuclear emission line region (LINER) nuclei, variations on…

High Energy Astrophysical Phenomena · Physics 2014-09-17 L. Hernández-García , O. González-Martín , J. Masegosa , I. Márquez

We have used the VLA to study radio variability among a sample of 18 low luminosity active galactic nuclei (LLAGNs), on time scales of a few hours to 10 days. The goal was to measure or limit the sizes of the LLAGN radio-emitting regions,…

Astrophysics · Physics 2009-11-10 James M. Anderson , James S. Ulvestad

We analyze the X-ray properties for a sample of 23 high probability AGN candidates with ultraviolet variability identified in Wasleske et al. (2022). Using data from the Chandra X-ray Observatory and the XMM-Newton Observatory, we find…

Astrophysics of Galaxies · Physics 2024-05-31 Erik J. Wasleske , Vivienne F. Baldassare