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Related papers: Revisiting Stochastic Variability of AGNs with Str…

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Analysing the long-term radio variability of active galactic nuclei (AGNs) is essential to understanding the physics of relativistic jets launched by supermassive black holes. We aim to connect the characteristic timescales obtained from a…

Astrophysics of Galaxies · Physics 2026-05-07 Sofia Kankkunen , Merja Tornikoski , Talvikki Hovatta

The radio luminosity functions (RLFs) of active galactic nuclei (AGNs) are traditionally measured based on total emission, which doesn't reflect the current activity of the central black hole. The increasing interest in compact radio cores…

Astrophysics of Galaxies · Physics 2018-12-26 Zunli Yuan , Jiancheng Wang , D. M. Worrall , Bin-Bin Zhang , Jirong Mao

The coevolution of supermassive black holes and their host galaxies represents a fundamental question in astrophysics. One approach to investigating this question involves comparing the star-formation rates (SFRs) of active galactic nuclei…

Astrophysics of Galaxies · Physics 2024-11-26 Bojun Zhang , Fan Zou , W. N. Brandt , Shifu Zhu , Nathan Cristello , Qingling Ni , Yongquan Xue , Zhibo Yu

The characteristic timescale at which the variability of active galactic nuclei (AGNs) turns from red noise to white noise can probe the accretion physics around supermassive black holes (SMBHs). A number of works have studied the…

Astrophysics of Galaxies · Physics 2024-09-17 Guowei Ren , Shuying Zhou , Mouyuan Sun , Yongquan Xue

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

Hundreds of Type 2 quasars have been identified in Sloan Digital Sky Survey (SDSS) data, and there is substantial evidence that they are generally galaxies with highly obscured central engines, in accord with unified models for active…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 A. J. Barth , A. Voevodkin , D. J. Carson , P. Woźniak

We measure the Eddington ratio distribution of local optical narrow-line active galactic nuclei (AGN) as a function of host galaxy properties, as a potential test of galaxy formation theories of AGN feedback. We extract central…

Astrophysics of Galaxies · Physics 2026-05-11 Michael R. Blanton , Arjun Suresh , Kyle B. Westfall , Dou Liu , John Moustakas

We report herschel observations of 100 very luminous, optically selected AGNs at z=2-3.5 with log(LUV)(erg/sec)> 46.5, where LUV=L1350A. The distribution in LUV is similar to the general distribution of SDSS AGNs in this redshift and…

Astrophysics of Galaxies · Physics 2016-03-23 Hagai Netzer , Caterina Lani , Raanan Nordon , Benny Trakhtenbrot , Paulina Lira , Ohad Shemmer

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

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

Most investigations of the X-ray variability of active galactic nuclei (AGN) have been concentrated on the detailed analyses of individual, nearby sources. A relatively small number of studies have treated the ensemble behaviour of the more…

Astrophysics of Galaxies · Physics 2016-09-21 F. Vagnetti , R. Middei , M. Antonucci , M. Paolillo , R. Serafinelli

Symbolic regression (SR) is a regression analysis based on genetic algorithms to search for mathematical expressions that best fit a given data set, by allowing the expressions themselves to mutate. We use the SR to analyze the parameter…

High Energy Astrophysical Phenomena · Physics 2023-10-31 P. Thongkonsing , P. Chainakun , T. Worrakitpoonpon , A. J. Young

We identify active galactic nuclei (AGN) in the Groth-Westphal Survey Strip (GSS) using the independent and complementary selection techniques of optical spectroscopy and photometric variability. We discuss the X-ray properties of these AGN…

We report Herschel Spitzer and Wise observations of 44 z=4.8 optically selected active galactic nuclei (AGNs). This sample contains the highest mass black holes (BHs) at this redshift. Ten of the objects were detected by Herschel and five…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Hagai Netzer , Rivay Mor , Benny Trakhtenbrot , Ohad Shemmer , Paulina Lira

The changing-look active galactic nucleus (CL-AGN), an extraordinary subpopulation of supermassive black holes, has attracted growing attention for understanding its nature. We present an analysis of the spectral properties of 203…

Astrophysics of Galaxies · Physics 2025-10-13 Yu-Heng Shen , Kai-Xing Lu , Wei-Jian Guo , Sha-Sha Li , Hai-Cheng Feng , Zhang Yue , Wen-Zhe Xi , Jian-Guo Wang , Jin-Ming Bai

We compare the average star formation (SF) activity in X-ray selected AGN hosts with mass-matched control inactive galaxies,including star forming and quiescent sources, at 0.5<z<2.5. Recent observations carried out by PACS, the 60-210um…

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

The scarce optical variability studies in spectrally classified Type 2 active galactic nuclei (AGNs) have led to the discovery of anomalous objects that are incompatible with the simplest unified models (UM). This paper focuses on the…

Astrophysics of Galaxies · Physics 2022-11-08 E. López-Navas , P. Arévalo , S. Bernal , Matthew J. Graham , L. Hernández-García , P. Lira , P. Sánchez-Sáez

We review recent evidence for a clear association between accretion onto supermassive black holes and star formation up to z~1 in the zCOSMOS survey. Star formation rates (SFRs) are determined from the [OII] emission-line strength and a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 John D. Silverman , zCOSMOS Collaboration , XMMCOSMOS Collaboration

We investigate the properties of a variability-selected complete sample of AGN in order to identify the mechanisms which cause large amplitude X-ray variability on time scales of years. A complete sample of 24 sources was constructed, from…

High Energy Astrophysical Phenomena · Physics 2016-08-09 N. L. Strotjohann , R. D. Saxton , R. L. C. Starling , P. Esquej , A. M. Read , P. A. Evans , G. Miniutti
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