English
Related papers

Related papers: AGN Variability

200 papers

There is growing evidence for star formation inside outflows of active galactic nuclei (AGNs). The formed stars are injected into bulges and give rise to perturbation of bulges. In this paper, we investigate the issues of non-rotating,…

Astrophysics of Galaxies · Physics 2024-12-25 Yue-Chang Peng , Jian-Min Wang , Yu Zhao , Luis C. Ho

The accretion flow in AGN is not well understood, motivating intensive monitoring campaigns of multiwavelength variability to probe its structure. One of the best of these is the 3 year optical/UV/X-ray approximately daily monitoring…

High Energy Astrophysical Phenomena · Physics 2025-11-05 Scott Hagen , Chris Done , Edward M. Cackett , Ethan R. Partington , Rick Edelson , Collin Lewin , Erin Kara , Jonathan Gelbord

We show that the rms-flux relation recently discovered in the X-ray light curves of Active Galactic Nuclei (AGN) and X-ray binaries (XRBs) implies that the light curves have a formally non-linear, exponential form, provided the rms-flux…

Astrophysics · Physics 2009-11-10 P. Uttley , I. M. McHardy , S. Vaughan

The properties of large-scale galactic outflows, such as their kinetic energy and momentum rates, correlate with the luminosity of the active galactic nucleus (AGN). This is well explained by the wind-driven outflow model, where a fraction…

Astrophysics of Galaxies · Physics 2020-09-30 Kastytis Zubovas , Emanuele Nardini

We have studied the flare characteristics of 55 AGN at 8 different frequency bands between 4.8 and 230 GHz. Our extensive database enables us to study the various observational properties of flares in these sources and compare our results…

Astrophysics · Physics 2009-11-13 T. Hovatta , E. Nieppola , M. Tornikoski , E. Valtaoja , M. F. Aller , H. D. Aller

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

Galactic outflows, driven by active galactic nuclei (AGN), play a crucial role in galaxy formation and in the self-regulated growth of supermassive black holes (BHs). AGN feedback couples to and affects gas, rather than stars, and in many,…

Astrophysics of Galaxies · Physics 2018-04-10 Tilman Hartwig , Marta Volonteri , Gohar Dashyan

Active galactic nuclei (AGN) with jets seen at small viewing angles are the most luminous and abundant objects in the $\gamma$-ray sky. AGN with jets misaligned along the line-of-sight appear fainter in the sky, but are more numerous than…

High Energy Astrophysical Phenomena · Physics 2015-06-15 M. Di Mauro , F. Calore , F. Donato , M. Ajello , L. Latronico

Active galactic nucleus (AGN)-driven gas outflows are one of the best tracers of AGN feedback in action, as these powerful outflows expel/heat or compress the surrounding interstellar medium (ISM), thus quenching or enhancing star-forming…

Astrophysics of Galaxies · Physics 2026-02-10 Ruisong Xia , Chen Qin , Huynh Anh N. Le , Yongquan Xue , Shifu Zhu , Mengqiu Huang , Hao Liu , Xiaozhi Lin

We conducted an analysis of gamma-ray variability in a large sample of jetted active galactic nuclei (AGNs) by utilizing archival Fermi-LAT light curves and applying damped random walk modeling to obtain variability amplitude. Our primary…

High Energy Astrophysical Phenomena · Physics 2026-05-21 Yongyun Chen , Qiusheng Gu , Junhui Fan , Dingrong Xiong , Xiaoling Yu , Xiaogu Zhong , Xiaotong Guo , Nan Ding

We study outflows driven by Active Galactic Nuclei (AGNs) using high- resolution simulations of idealized z=2 isolated disk galaxies. Episodic accretion events lead to outflows with velocities >1000 km/s and mass outflow rates up to the…

Astrophysics of Galaxies · Physics 2015-06-18 Jared M. Gabor , Frédéric Bournaud

Radiation from the blazar class of of active galactic nuclei (AGN) exhibits fast time variability which is usually ascribed to instabilities in the emission region near the central supermassive black hole. The variability time scale is…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Kenji Nakagawa , Masaki Mori

We analyze the variability of the parsec-scale jet directions in active galactic nuclei (AGNs). Our analysis involves 317 AGNs at frequencies ranging from 2 to 43 GHz, and is made possible by developing an automatic inner jet direction…

High Energy Astrophysical Phenomena · Physics 2025-02-11 Ivan Kostrichkin , Alexander Plavin , Alexander Pushkarev , Marina Butuzova

The characteristic timescale ($\tau$) of continuum variability of the accretion disk in active galactic nuclei (AGNs) is known to be related to the thermal timescale, which is predicted to scale with AGN luminosity ($L$) and restframe…

Astrophysics of Galaxies · Physics 2025-03-26 Suyeon Son , Minjin Kim , Luis C. Ho

Context: Variations in the mass accretion rate appear to be responsible for the rapid transitions in spectral type that are observed in increasingly more active galactic nuclei (AGNs). These objects are now labeled "changing-look" AGNs and…

Astrophysics of Galaxies · Physics 2020-04-15 F. Marin , D. Hutsemékers

With the discovery of gravitational waves (GWs), Active Galactic Nuclei (AGN) disks have emerged as an interesting environment for hosting a fraction of their sources. AGN disks are conducive to forming both long and short Gamma-Ray Bursts…

High Energy Astrophysical Phenomena · Physics 2025-03-07 Hoyoung D. Kang , Rosalba Perna , Davide Lazzati , Yi-Han Wang

Active Galactic Nuclei (AGNs) release huge amounts of energy in their host galaxies, which, if the coupling is sufficient, can affect the interstellar medium (ISM). We use a high-resolution simulation ($\sim6$ pc) of a z $\sim2$…

Astrophysics of Galaxies · Physics 2014-10-27 Orianne Roos , Stéphanie Juneau , Frédéric Bournaud , Jared Gabor

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

The long term X-ray spectral variability of ten active galactic nuclei (AGN) shows a positive spectral index-flux correlation for each object (Sobolewska & Papadakis 2009). An inner advection dominated accretion flow (ADAF) may connect to a…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Xinwu Cao , Jun-Xian Wang

Observations at multiple wavelengths are reviewed to search for evidence for fueling mechanisms in galaxies, both for nuclear starbursts and AGN activity. Although it is undisputed that dynamical perturbations such as bars or tidal…

Astrophysics · Physics 2007-05-23 F. Combes
‹ Prev 1 8 9 10 Next ›