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Related papers: Local Active Galactic Nuclei with Large Broad-H{\a…

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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

We analyzed a sample of $\sim$113,000 galaxies ($\rm z < 0.3$) from the Sloan Digital Sky Survey, divided into star-forming, composite, Seyfert, and LINER types, to explore the relationships between UV-to-optical colors ($\rm u-r$), star…

Astrophysics of Galaxies · Physics 2024-12-20 Huynh Anh N. Le , Yongquan Xue

As part of a program to study the evolution of active galactic nuclei (AGN) in clusters of galaxies, we present our results for Abell 2104. A deep Chandra observation of this massive, z = 0.154 cluster reveals a significant X-ray point…

Astrophysics · Physics 2009-11-07 Paul Martini , Daniel D. Kelson , John S. Mulchaey , Scott C. Trager

Changing-look (CL) Active Galactic Nuclei (AGNs), characterized by appearance/disappearance of broad emission lines in the span of a few years, present a challenge for the AGN unified model, whereby the Type 1 vs. Type 2 dichotomy results…

Low Luminosity Active Galactic Nuclei (LLAGNs) are contaminated by the light of their host galaxies, thus they cannot be detected by the usual colour techniques. For this reason their evolution in cosmic time is poorly known. Variability is…

Astrophysics of Galaxies · Physics 2009-02-09 F. Vagnetti , K. Boutsia , D. Trevese

Changing-look active galactic nuclei (AGNs) are a special class of AGNs that change their spectral type from type 1 to type 2 or vice versa. In recent years, a number of changing-look blazars (CLBs) were also reported, which transition…

High Energy Astrophysical Phenomena · Physics 2024-03-04 Shi-Ju Kang , Bing Lyu , Qingwen Wu , Yong-Gang Zheng , Junhui Fan

Accretion states, which are universally observed in stellar-mass black holes in X-ray binaries, are also anticipated in active galactic nuclei (AGN). This is the case at low luminosities, when the jet-corona coupling dominates the energy…

High Energy Astrophysical Phenomena · Physics 2021-04-28 Juan A. Fernández-Ontiveros , Teo Muñoz-Darias

The term 'active galactic nuclei' (AGN) subtends a huge variety of objects, classified on their properties at different wavelengths. Peaked sources (PS) represent a class of AGN at the first stage of evolution, characterised by a peaked…

Astrophysics of Galaxies · Physics 2024-09-11 A. Vietri , M. Berton , E. Järvelä , M. Kunert-Bajraszewska , S. Ciroi , I. Varglund , B. Dalla Barba , E. Sani , L. Crepaldi

Given the existence of the M_BH-sigma relation, models of self-regulated black hole (BH) growth require both a fuel supply and growth of the host bulge to deepen the potential, or else the system will either starve or self-regulate without…

Astrophysics · Physics 2014-11-18 Philip F. Hopkins , Lars Hernquist

We explore the connection between different classes of active galactic nuclei (AGNs) and the evolution of their host galaxies, by deriving host galaxy properties, clustering, and Eddington ratios of AGNs selected in the radio, X-ray, and…

Astrophysics of Galaxies · Physics 2009-03-24 Ryan C. Hickox , the Bootes survey collaboration

We investigate the star formation activity and black hole scaling relations in a sample of 1451 AGN hosted by dwarf galaxies at redshift 0.5 to 0.9, drawn from the VIPERS survey. The sample comprises Seyferts and LINERs identified through…

Astrophysics of Galaxies · Physics 2025-10-01 G. Mountrichas , M. Siudek , F. J. Carrera

In contrast to massive, bulge hosting galaxies, very few supermassive black holes (SMBHs) are known in either low mass, or bulgeless galaxies. Such a population could provide clues to the origins of SMBHs and to secular pathways for their…

This paper is the first in a series of preparing and analyzing spectral and other properties for a database of already discovered Changing-Look active galactic nuclei (CL AGNs). Here, we focus on the spectral fitting and analysis of broad…

High Energy Astrophysical Phenomena · Physics 2024-03-12 Swayamtrupta Panda , Marzena Śniegowska

We use a sample of 64 nearby (D=7-45 Mpc) disk galaxies including 45 AGN and 19 non-AGN, that have high spatial resolution multiline CO observations obtained with the ALMA and/or PdBI arrays to study the distribution of cold molecular gas…

Seyfert nuclei are typical active galactic nuclei (AGNs) in the local universe, which are thought to be powered by gas accretion onto a supermassive black hole (SMBH). The dynamical effect exerted either by non-axisymmetric gravitational…

Astrophysics · Physics 2009-10-31 Yoshiaki Taniguchi

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

It is still a matter of intense debate how supermassive black holes (SMBH) grow, and the role played by feedback from active galactic nuclei (AGN) in the co-evolution of SMBHs and galaxies. To test the coevolution proposed by theoretical…

Astrophysics of Galaxies · Physics 2022-11-30 George Mountrichas , Francesco Shankar

The Lick AGN Monitoring Project targeted 13 nearby Seyfert 1 galaxies with the intent of measuring the masses of their central black holes using reverberation mapping. The sample includes 12 galaxies selected to have black holes with masses…

Changing-look active galactic nuclei (CL-AGNs) as a new subpopulation challenge some fundamental physics of AGNs because the timescales of the phenomenon can hardly be reconciled with accretion disk models. In this Letter{\textit{}}, we…

Astrophysics of Galaxies · Physics 2020-11-18 Jian-Min Wang , Edi Bon

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…

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