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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

In order to relate the observed evolution of the galaxy stellar mass function and the luminosity function of active galactic nuclei (AGN), we explore a co-evolution scenario in which AGN are associated only with the very last phases of the…

Astrophysics of Galaxies · Physics 2018-11-28 Neven Caplar , Simon J. Lilly , Benny Trakhtenbrot

We present a census of the active black hole population at 1<z<2, by constructing the bivariate distribution function of black hole mass and Eddington ratio, employing a maximum likelihood fitting technique. The study of the active black…

Active galactic nuclei (AGNs) exhibit stochastic optical variability, commonly characterized by a damped random walk. The damping timescale is of particular interest because it is related to fundamental properties of the central black hole,…

Astrophysics of Galaxies · Physics 2025-09-29 Ruisong Xia , Zhen-Yi Cai , Yongquan Xue , Xian-Liang Lu , Guowei Ren , Shuying Zhou , Mouyuan Sun , Shifu Zhu , Zhen-Bo Su , Hao Liu

We aim to study the effect of environment on the presence and fuelling of Active Galactic Nuclei (AGN) in massive galaxy clusters. We explore the use of different AGN detection techniques with the goal of selecting AGN across a broad range…

Astrophysics of Galaxies · Physics 2015-06-05 Alison J. Klesman , Vicki L. Sarajedini

This is the second paper of our series of works of studying the effects of active galactic nuclei (AGN) feedback on the cosmological evolution of an isolated elliptical galaxy by performing two-dimensional high-resolution hydrodynamical…

High Energy Astrophysical Phenomena · Physics 2018-09-05 Doosoo Yoon , Feng Yuan , Zhao-Ming Gan , Jeremiah P. Ostriker , Ya-Ping Li , Luca Ciotti

There is growing observational evidence for dwarf galaxies hosting active galactic nuclei (AGN), including hints of AGN-driven outflows in dwarfs. However, in the common theoretical model of galaxy formation, efficient supernova (SN)…

Astrophysics of Galaxies · Physics 2022-09-02 Sophie Koudmani , Debora Sijacki , Matthew C. Smith

The abundance of active galactic nuclei (AGN) in cosmic voids is relatively unexplored in the literature, but can potentially provide new constraints on the environmental dependence of AGN activity and the AGN-host co-evolution. We…

Astrophysics of Galaxies · Physics 2021-12-01 H. D. Mishra , X. Dai , E. Guerras

We use data from a two-year intensive RXTE monitoring campaign of the broad-line radio galaxy 3C 390.3 to investigate its stationarity. In order to exploit the potential information contained in a time series more efficiently, we use a…

Astrophysics · Physics 2007-05-23 M. Gliozzi , I. E. Papadakis , R. M. Sambruna , M. Eracleous

The emission line luminosity function of active galactic nuclei (AGN) is measured from about 3000 AGN included in the main galaxy sample of the Sloan Digital Sky Survey within a redshift range of $0<z<0.15$. The $\Ha$ and [OIII]$\lambda…

A summary critique is presented of the topics discussed at a workshop entitled ``Probing the Physics of Active Galactic Nuclei by Multi-wavelength Monitoring'' held at Goddard Space Flight Center 21-23 June 2000. Particular emphasis is…

Astrophysics · Physics 2007-05-23 R. D. Blandford

The feedback from active galactic nuclei (AGN) plays a crucial role in regulating the thermodynamics and the dynamics of the intracluster medium (ICM). Studying the turbulent patterns of the hot and warm ionized phases may allow us to…

Astrophysics of Galaxies · Physics 2025-05-14 Stefano Sotira , Franco Vazza , Fabrizio Brighenti

The effect of Active Galactic Nuclei (AGN) on their host galaxies -- in particular their levels of star formation -- remains one of the key outstanding questions of galaxy evolution. Successful cosmological models of galaxy evolution…

High-redshift active galactic nuclei (AGN) serve as powerful probes of early black-hole growth, galaxy formation, and the evolving intergalactic medium (IGM). In this work, we use Lumina, a cosmological radiation-hydrodynamic simulation…

Deep X-ray surveys by Chandra and XMM-Newton have resolved about 80% of the 2-10 keV cosmic extragalactic X-ray background (CXRB) into point sources, the majority of which are obscured AGN. The obscuration might be connected to processes…

Astrophysics · Physics 2008-11-26 D. R. Ballantyne , Y. Shi , G. H. Rieke , J. L. Donley , C. Papovich , J. R. Rigby

We study the statistical properties of the Normalized Excess Variance of variability process characterized by a red-noise power spectral density (PSD), as the case of Active Galactic Nuclei (AGN). We perform Monte Carlo simulations of…

High Energy Astrophysical Phenomena · Physics 2015-06-04 V. Allevato , M. Paolillo , I. Papadakis , C. Pinto

X-ray spectra of active galactic nuclei (AGN) consist of several different emission and absorption components, which are often fitted manually with models chosen on a case-by-case basis. However, it becomes very hard for a survey with a…

High Energy Astrophysical Phenomena · Physics 2022-11-23 Lingsong Ge , Stéphane Paltani , Dominique Eckert

X-ray surveys of active galactic nuclei (AGNs) provide direct constraints on the properties of individual AGNs, such as their emission, obscuration, and accretion rate. Previous AGN population synthesis models have not addressed such…

High Energy Astrophysical Phenomena · Physics 2026-05-19 D. Gerolymatou , S. Paltani , C. Ricci , T. T. Ananna

Jetted Active Galactic Nuclei (AGN) exhibit variability across a wide range of time scales. Traditionally, this variability can often be modeled well as a stochastic process. However, in certain cases, jetted AGN variability displays…

High Energy Astrophysical Phenomena · Physics 2025-01-03 P. Penil , A. Domínguez , S. Buson , M. Ajello , S. Adhikari , A. Rico

We assemble a sample of 733 dwarf galaxies ($M_{\ast} \le 10^{9.5} \text{M}_\odot$) with signatures of active galactic nuclei (AGN) and explore the intersection between different AGN selection techniques. Objects in our database are…

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