English
Related papers

Related papers: A forward modelling approach to AGN variability --…

200 papers

[Abridged] We present a comprehensive investigation of the cosmological evolution of the luminosity function (LF) of galaxies and active galactic nuclei (AGN) in the infrared (IR). Based on the observed dichotomy in the ages of stellar…

Variability is a main property of active galactic nuclei (AGN) and it was adopted as a selection criterion using multi epoch surveys conducted for the detection of supernovae (SNe). We have used two SN datasets. First we selected the AXAF…

Astrophysics of Galaxies · Physics 2010-03-03 K. Boutsia , B. Leibundgut , D. Trevese , F. Vagnetti

This work develops application techniques for stochastic modelling of Active Galactic Nuclei (AGN) variability as a probe of accretion disk physics. Stochastic models, specifically Continuous Auto-Regressive Moving Average (CARMA) models,…

Instrumentation and Methods for Astrophysics · Physics 2019-09-06 Jackeline Moreno , Michael S. Vogeley , Gordon T. Richards

Active galactic nuclei (AGN) show a range of morphologies and dynamical properties, which are determined not only by parameters intrinsic to the central engine but also their interaction with the surrounding environment. We investigate the…

High Energy Astrophysical Phenomena · Physics 2022-08-16 Soham Mandal , Paul C. Duffell , Yuan Li

We compare predictions of how Active Galactic Nuclei (AGN) populate host galaxies at low redshifts to observations, finding large discrepancies between cosmological simulation predictions and observed patterns. Modern cosmological…

Astrophysics of Galaxies · Physics 2025-08-08 Arjun Suresh , Michael R. Blanton , Douglas Rennehan

Modern cosmological simulations rely heavily on feedback from active galactic nuclei (AGN) in order to stave off overcooling in massive galaxies and galaxy groups and clusters. An important independent test is whether or not the simulations…

Active galactic nuclei (AGN) are known for irregular variability on all time scales, down to intra-day variability with relative variations of a few percent within minutes to hours. On such short timescales, unexplored territory, such as…

Astrophysics of Galaxies · Physics 2015-11-27 Taeseok Lee , Sascha Trippe , Junghwan Oh , Do-Young Byun , Bong-Won Sohn , Sang-Sung Lee

Number of monitoring observations of continuum emission from Active Galactic Nuclei (AGNs) have been made in optical--X-ray bands. The results obtained so far show (i) random up and down on timescales longer than decades, (ii) no typical…

Astrophysics · Physics 2007-05-23 T. Kawaguchi , S. Mineshige

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

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

Gamma-ray flares from Active Galactic Nuclei (AGN) show substantial variability on ultrafast timescales (i.e. shorter than the light crossing time of the AGN's supermassive black hole). We propose that ultrafast variability is a byproduct…

High Energy Astrophysical Phenomena · Physics 2023-04-12 Emanuele Sobacchi , Tsvi Piran , Luca Comisso

Variability in the X-rays is a key ingredient in understanding and unveiling active galactic nuclei (AGN) properties. In this band flux variations occur on short time scales (hours) as well as on larger times scales. While short time scale…

High Energy Astrophysical Phenomena · Physics 2017-03-08 R. Middei , F. Vagnetti , S. Bianchi , F. La Franca , M. Paolillo , F. Ursini

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…

We compiled a sample of 73 active galactic nuclei (AGNs) with reverberation mapping (RM) observations from RM campaigns including our ongoing campaign of monitoring super-Eddington accreting massive black holes (SEAMBHs). This sample covers…

We introduce our project, AGNSTRONG (Active Galactic Nuclei and STaR fOrmation in Nearby Galaxies). Our research goals encompass investigating the kinematic properties of ionized and molecular gas outflows, understanding the impact of AGN…

Astrophysics of Galaxies · Physics 2024-05-16 Huynh Anh N. Le , Chen Qin , Yongquan Xue , Shifu Zhu , Kim Ngan N. Nguyen , Ruisong Xia , Xiaozhi Lin

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

X-ray variability is a well-established characteristic of active galactic nuclei (AGN), known to correlate inversely with both the supermassive black hole mass and luminosity, although the degree of each remains a topic of debate. The…

The unified model of active galactic nuclei (AGN) includes a toroidal obscuring structure to explain the differences between Type I and Type II AGN as an effect of inclination angle. This toroidal structure is thought to be 'clumpy' as the…

Astrophysics of Galaxies · Physics 2023-01-19 Isaiah Cox , Nuria Torres-Alba , Stefano Marchesi , Xiurui Zhao , Marco Ajello , Andrealuna Pizzetti , Ross Silver

Observations and theoretical simulations suggest that the large scale environment plays a significant role in how galaxies form and evolve and, in particular, whether and when galaxies host an actively accreting supermassive black hole in…

Astrophysics of Galaxies · Physics 2025-07-16 Anish S. Aradhey , Anca Constantin , Michael S. Vogeley , Kelly A. Douglass

Active galactic nuclei (AGNs) exhibit variability in their luminosities with timescales that correlate with the mass of the black hole at the centre of the AGN. Presently, the empirical correlation lacks sufficient precision to confidently…

Astrophysics of Galaxies · Physics 2025-12-22 Adrien Hélias , Sarah C. Gallagher , Pauline Barmby