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Related papers: Robust AGN and host-galaxy decomposition in optica…

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In this study, our primary objective is to compare the properties of SMBH and their host galaxies between type 1 and type 2 AGN. In our analysis, we use X-ray detected sources in two fields, namely the eFEDS and the COSMOS-Legacy. To…

Astrophysics of Galaxies · Physics 2023-12-20 G. Mountrichas , I. Georgantopoulos

To gain insights into long-term Active Galactic Nuclei (AGN) variability, we analyze an AGN sample from the Sloan Digital Sky Survey (SDSS) and compare their photometry with observations from the Hyper Suprime-Cam survey (HSC) observed…

Astrophysics of Galaxies · Physics 2020-02-12 Neven Caplar , Theodore Pena , Sean D. Johnson , Jenny E. Greene

We explore the evolution with redshift of the rest-frame colours and space densities of AGN hosts (relative to normal galaxies) to shed light on the dominant mechanism that triggers accretion onto supermassive black holes as a function of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 A. Georgakakis , A. L. Coil , C. N. A. Willmer , K. Nandra , D. D. Kocevski , M. C. Cooper , D. J. Rosario , D. C. Koo , J. R. Trump , S. Juneau

(Abridged)We explore the potential of optical variability selection methods to identify AGN, including those challenging to detect with conventional techniques. Using the unprecedented combination of depth, sky coverage, and cadence of the…

Astrophysics of Galaxies · Physics 2026-01-28 P. Arévalo , P. Sánchez-Sáez , B. Sotomayor , P. Lira , F. E. Bauer , S. Ríos

We examine the continuum variability of active galactic nuclei (AGNs) by analyzing the multi-epoch spectroscopic data from the Sloan Digital Sky Survey. To achieve this, we utilized approximately 2 million spectroscopy pairwise combinations…

Astrophysics of Galaxies · Physics 2025-11-13 Minjin Kim , Suyeon Son , Luis C. Ho

Variability has proven to be a powerful tool to detect active galactic nuclei (AGN) in multi-epoch surveys. The new-generation facilities expected to become operational in the next few years will mark a new era in time-domain astronomy and…

The survey of the COSMOS field by the VLT Survey Telescope is an appealing testing ground for variability studies of active galactic nuclei (AGN). With 54 r-band visits over 3.3 yr and a single-visit depth of 24.6 r-band mag, the dataset is…

Astrophysics of Galaxies · Physics 2021-01-27 D. De Cicco , F. E. Bauer , M. Paolillo , S. Cavuoti , P. Sánchez-Sáez , W. N. Brandt , G. Pignata , M. Vaccari , M. Radovich

Changing-look transitions challenge our understanding of active galactic nuclei (AGN), exhibiting dramatic changes in broad-line emission and continuum flux on timescales of months to years. We present a detailed study of the…

Astrophysics of Galaxies · Physics 2026-04-10 Joel Carpenter , Sandra Raimundo , Charlotte Angus , Katie Auchettl

In a series of papers based on the FIRST and Sloan Digital Sky Surveys (SDSS), we investigate the local population of star-forming galaxies and Active Galactic Nuclei (AGN) in order to clarify the link between these two types of activity,…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-25 Pietro M. Reviglio , David J. Helfand

The ionizing fluxes from quasars and other active galactic nuclei (AGN) are critical for interpreting their emission-line spectra and for photoionizing and heating the intergalactic medium (IGM). Using far-ultraviolet spectra from the…

Astrophysics of Galaxies · Physics 2015-06-22 Matthew L. Stevans , J. Michael Shull , Charles W. Danforth , Evan M. Tilton

Galaxy mergers are believed to play an important role in triggering rapid supermassive black hole (SMBH) growth. As merging nuclei approach each other, the physical properties of the participating galaxies and the associated SMBH growth are…

A new sample of 204 low-mass black holes (LMBHs) in active galactic nuclei (AGNs) is presented with black hole masses in the range of (1-20) * 10^5 M_sun. The AGNs are selected from a systematic search among galaxies in the Seventh Data…

Astrophysics of Galaxies · Physics 2018-05-04 He-Yang Liu , Weimin Yuan , Xiao-Bo Dong , Hongyan Zhou , Wen-Juan Liu

We use a sample of over 5000 active galactic nuclei (AGN) with extended morphologies at z<0.8 from the Sloan Digital Sky Survey (SDSS) to study the ensemble optical variability as a function of rest-frame time lag and AGN luminosity with…

Astrophysics of Galaxies · Physics 2014-10-01 Unai Gallastegui-Aizpun , Vicki L. Sarajedini

The connection between AGN and their host galaxies has been widely studied over recent years, showing it to be of great importance for providing answers to some fundamental questions related with AGN fueling mechanisms, their formation and…

We present a comprehensive analysis of the X-ray spectral properties of 198 newly identified active galactic nuclei (AGNs), leveraging archival data from the {\it Chandra} X-ray Observatory. All these AGNs exhibit a powerlaw spectral…

High Energy Astrophysical Phenomena · Physics 2024-10-08 Samrat Ghosh , Samir Mandal , Sudip Bhattacharyya , Shivam Kumaran

Near-infrared long-slit spectroscopy has been used to study the stellar population (SP) of the low luminosity active galactic nuclei (AGN) and matched analogues (LLAMA) sample. To perform the SP fits we have employed the X-shooter simple…

An empirical model is presented that links, for the first time, the demographics of AGN to their ensemble X-ray variability properties. Observations on the incidence of AGN in galaxies are combined with (i) models of the Power Spectrum…

High Energy Astrophysical Phenomena · Physics 2021-10-13 A. Georgakakis , I. Papadakis , M. Paolillo

We analyze morphologies of the host galaxies of 35 X-ray selected active galactic nucleus (AGNs) at $z\sim2$ in the Cosmic Evolution Survey (COSMOS) field using Hubble Space Telescope/WFC3 imaging taken from the Cosmic Assembly…

Astrophysics of Galaxies · Physics 2015-06-18 Lulu Fan , Guanwen Fang , Yang Chen , Jinrong Li , Xuanyi Lv , Kirsten Kraiberg Knudsen , Xu Kong

The cosmic X-ray background (XRB) spectrum and active galaxy number counts encode essential information about the spectral evolution of active galactic nuclei (AGNs) and have been successfully modeled by XRB synthesis models for many years.…

High Energy Astrophysical Phenomena · Physics 2019-04-24 M. S. Avirett-Mackenzie , D. R. Ballantyne

The unification of active galactic nuclei (AGN) is a model that has been difficult to test due to the lack of knowledge on the intrinsic luminosities of the objects. We present a test were we probe the model by statistical investigation of…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-05 Beatriz Villarroel , Andreas Korn , Yoshiki Matsuoka