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Related papers: Systematic Analysis of Changing-look AGN Variabili…

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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

We present a comprehensive study of five nearby active galaxies featuring large (tens of kpc) extended emission-line regions (EELRs). The study is based on large-format integral field spectroscopic observations conducted with the Multi Unit…

Astrophysics of Galaxies · Physics 2025-11-05 C. Finlez , E. Treister , F. Bauer , M. Koss , W. Keel , W. Maksym , L. Sartori , G. Venturi , C. Ricci , N. Nagar , C. Riesco , Y. Díaz , M. Parra

We study the optical variability characteristics of Active Galactic Nuclei (AGN) from the Swift Burst Alert Telescope (BAT) AGN catalogue by utilising approximately five years of optical light curves from the Zwicky Transient Facility (ZTF)…

High Energy Astrophysical Phenomena · Physics 2025-08-12 Vivek Kumar Jha , Debbijoy Bhattacharya , Hum Chand

We study the properties of the host galaxies of Changing-Look Active Galactic Nuclei (CL AGNs) with the aim of understanding the conditions responsible for triggering CL activity. We find that CL AGN hosts primarily reside in the so-called…

Astrophysics of Galaxies · Physics 2021-03-17 Sierra A. Dodd , Jamie A. P. Law-Smith , Katie Auchettl , Enrico Ramirez-Ruiz , Ryan J. Foley

Dual Active Galactic Nuclei (dual AGNs), a phase in some galaxy mergers during which both central supermassive black holes (SMBHs) are active, are expected to be a key observable stage leading up to SMBH mergers. Constraining the population…

We present the results of a systematic search for quasars in the Catalina Real-time Transient Survey exhibiting both strong photometric and spectroscopic variability over a decadal baseline. We identify 73 sources with specific patterns of…

We use highly spectroscopically complete deep and wide-area Chandra surveys to determine the cosmic evolution of hard X-ray-selected AGNs. We determine hard X-ray luminosity functions (HXLFs) for all spectral types and for broad-line AGNs…

Astrophysics · Physics 2008-11-26 A. J. Barger , L. L. Cowie , R. F. Mushotzky , Y. Yang , W. -H. Wang , A. T. Steffen , P. Capak

Offset active galactic nuclei (AGNs) are AGNs that are in ongoing galaxy mergers, which produce kinematic offsets in the AGNs relative to their host galaxies. Offset AGNs are also close relatives of dual AGNs. We conduct a systematic search…

Astrophysics of Galaxies · Physics 2015-06-19 Julia M. Comerford , Jenny E. Greene

We build a simple physical model to study the high-redshift active galactic Nucleus (AGN) evolution within the co-evolution framework of central black holes (BHs) and their host galaxies. The correlation between the circular velocity of a…

Astrophysics of Galaxies · Physics 2016-09-21 Jirong Mao , Minsun Kim

Active Galactic Nuclei (AGN) are remarkable astronomical sources emitting over the whole electromagnetic spectrum, with different bands providing unique windows on distinct sub-structures and their related physics. AGN come in a large…

High Energy Astrophysical Phenomena · Physics 2023-02-27 Paolo Padovani

Active galactic nuclei (AGNs) exhibit complex variability across multiple wavelengths, reflecting diverse physical processes near their central engines. This work investigates the temporal variability of four AGNs Mrk~509, NGC~5548,…

Astrophysics of Galaxies · Physics 2026-05-12 R. A. A. Souza , E. Hatziminaoglou , A. de Pádua Santos , T. Stosic

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

Information on the structure around active galactic nuclei (AGN) has long been derived from measuring lags in their varying light output at different wavelengths. In principle, infrared data would reach to larger radii, potentially even…

Astrophysics of Galaxies · Physics 2021-03-17 E. Elmer , M. Merrifield , O. Almaini , W. G. Hartley , D. T. Maltby

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

Active Galactic Nucleus (AGN) variability can be used to study the physics of the region in the vicinity of the central black hole. In this paper, we investigated intra-night optical variability of AGN in the COSMOS field in order to…

Astrophysics of Galaxies · Physics 2018-09-12 Joonho Kim , Marios Karouzos , Myungshin Im , Changsu Choi , Dohyeong Kim , Hyunsung D. Jun , Joon Hyeop Lee , Mar Mezcua

We present the first X-ray observations of three sources belonging to a new AGN class: the naked AGNs. Based on optical spectroscopic studies, these sources appear as classical type 2 (obscured) AGNs, with only narrow emission lines.…

Astrophysics · Physics 2011-02-11 M. Gliozzi , R. M. Sambruna , L. Foschini

The rapid variability observed in very-high-energy (VHE) sources-such as pulsars, gamma-ray bursts (GRBs), and flares from active galactic nuclei (AGN)-can be used to detect or constrain a potential violation of Lorentz invariance (LIV).…

High Energy Astrophysical Phenomena · Physics 2026-04-14 Cyann Plard , Sami Caroff , the CTAO-LST project

We investigate the differences in the stellar population properties, the structure, and the environment between massive compact star-forming galaxies (cSFGs) with or without active galactic nucleus (AGN) at $2<z<3$ in the five…

Astrophysics of Galaxies · Physics 2022-08-10 Shiying Lu , Yizhou Gu , Guanwen Fang , Qirong Yuan , Min Bao , Xiaotong Guo

[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…

Active Galactic Nuclei (AGN) are highly energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, which present unique observational signatures covering the full electromagnetic spectrum (and more) over…

High Energy Astrophysical Phenomena · Physics 2023-04-05 Stefano Bianchi , Vincenzo Mainieri , Paolo Padovani