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Related papers: AGN Coronal Emission models I. The Predicted Radio…

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We calculate the radiation spectrum and its time variability of the black hole accretion disk-corona system based on the three-dimensional magnetohydrodynamic simulation. In explaining the spectral properties of active galactic nuclei…

Astrophysics · Physics 2015-05-13 Norita Kawanaka , Yoshiaki Kato , Shin Mineshige

The physical nature of the X-ray/radio correlation of AGN is still an unsolved question. High angular resolution observations are necessary to disentangle the associated energy dynamics into nuclear and stellar components. We present…

Astrophysics · Physics 2014-11-18 Jens Zuther , Sebastian Fischer , Andreas Eckart

We develop a physically motivated, spherical corona model to investigate the frequency-dependent time lags in AGN. The model includes the effects of Compton up-scattering between the disc UV photons and coronal electrons, and the subsequent…

High Energy Astrophysical Phenomena · Physics 2022-08-31 P. Chainakun , A. Watcharangkool , A. J. Young , S. Hancock

This paper presents an in depth look at the jet and coronal properties of 41 AGN. Utilizing the highest quality NuSTAR, XMM-Newton, and NVSS 1.4 GHz data, we find that the radio Eddington luminosity inversely scales with X-ray reflection…

High Energy Astrophysical Phenomena · Physics 2017-02-08 Ashley L. King , Anne Lohfink , Erin Kara

Most of the Active Galactic Nuclei (AGN) are radio-quiet (RQ) and, differently from radio-loud (RL) AGN, do not show signature of large-scale and powerful jets. The physical origin of their radio emission remains then broadly unclear. The…

High Energy Astrophysical Phenomena · Physics 2023-09-06 P. O. Petrucci , V. Piétu , E. Behar , M. Clavel , S. Bianchi , G. Henri , S. Barnier , S. Chen , J. Ferreira , J. Malzac , R. Belmont , S. Corbel , M. Coriat

The main characteristics of the average spectrum of radio quiet AGN in the UV and X-ray range are reviewed, and the emission mechanisms are discussed in the framework of accretion disk models, in particular the ``irradiated cold…

Astrophysics · Physics 2007-05-23 S. Collin , A. Abrassart , B. Czerny , A. -M. Dumont , M. Mouchet

The corona is an integral component of active galactic nuclei (AGNs) which can produce the X-ray emission. However, many of its physical properties and the mechanisms powering this emission remain a mystery. In this work, we study the…

High Energy Astrophysical Phenomena · Physics 2025-07-08 Haiyun Zhang , Dahai Yan , Li Zhang , Niansheng Tang

Increasing evidence shows that AGN with radio detections have more perturbed ionized gas kinematics and higher outflow detection rates, suggesting a link between radio emission and these processes. In galaxies with weak or ambiguous AGN…

Astrophysics of Galaxies · Physics 2026-03-04 Marco Albán , Dominika Wylezalek , Pranav Kukreti , Rogemar A. Riffel , Rogerio Riffel

A soft X-ray excess above the 2-10 keV power law extrapolation is generally observed in AGN X-ray spectra. Presently there are two competitive models to explain it: blurred ionized reflection and warm Comptonisation. In the latter case,…

High Energy Astrophysical Phenomena · Physics 2020-02-12 P. -O. Petrucci , D. Gronkiewicz , A. Rozanska , R. Belmont , S. Bianchi , B. Czerny , G. Matt , J. Malzac , R. Middei , A. De Rosa , F. Ursini , M. Cappi

We present the first systematic study of short-timescale X-ray variability in radio-quiet active galactic nuclei (AGN), utilizing archival Chandra observations of approximately 3,000 broad-line AGN selected from the SDSS and DESI…

High Energy Astrophysical Phenomena · Physics 2025-12-09 Xiurui Zhao , Luca Comisso , Stefano Marchesi , Marco Ajello , Elias Kammoun , Yue Shen , Qiaoya Wu

We examine atmospheric heating by radio active galactic nuclei (AGN) in distant X-ray clusters by cross correlating clusters selected from the 400 Square Degree (400SD) X-ray Cluster survey with radio sources in the NRAO VLA Sky Survey.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 C. -J. Ma , B. R. McNamara , P. E. J. Nulsen , R. Schaffer , A. Vikhlinin

A wide-frequency radio study of Active Galactic Nuclei (AGN) is crucial to evaluate the intervening radiative mechanisms responsible for the observed emission and relate them with the underlying accretion physics. We present wide frequency…

We have used the VLBA at 5 GHz to observe all galaxies with nuclear radio flux densities above 3.5 mJy found in a VLA survey at 15 GHz of a sample of nearby LINER galaxies. All galaxies were detected revealing high brightness temperature…

Astrophysics · Physics 2009-10-31 Heino Falcke , Neil M. Nagar , Andrew S. Wilson , James S. Ulvestad

We investigate the origin of the parsec-scale radio emission from the changing-look active galactic nucleus (AGN) of Mrk 590, and examine whether the radio power has faded concurrently with the dramatic decrease in accretion rates observed…

Astrophysics of Galaxies · Physics 2016-06-30 J. Y. Koay , M. Vestergaard , H. E. Bignall , C. Reynolds , B. M. Peterson

We outline a science case for next-generation wide-field spectroscopic surveys aimed at connecting the physics of the accretion disc and X-ray corona in active galactic nuclei (AGN) with the properties of their nebular regions and…

Instrumentation and Methods for Astrophysics · Physics 2026-01-01 Susanna Bisogni , Giustina Vietri , Andrea Travascio , Adriana Gargiulo , Chiara Mancini , Swayamtrupta Panda

mm-wave emission from Active Galactic Nuclei (AGN) may hold the key to understanding the physical origin of their radio cores. The correlation between radio/mm and X-ray luminosity may suggest a similar physical origin of the two sources.…

Astrophysics of Galaxies · Physics 2018-05-23 Ehud Behar , Stuart Vogel , Ranieri D. Baldi , Krista L. Smith , Richard F. Mushotzky

We investigate faint radio emission from low- to high-luminosity Active Galactic Nuclei (AGN) selected from the Sloan Digital Sky Survey (SDSS). Their radio properties are inferred by co-adding large ensembles of radio image cut-outs from…

Astrophysics · Physics 2008-11-26 W. H. de Vries , J. A. Hodge , R. H. Becker , R. L. White , D. J. Helfand

The primary X-ray emission in active galactic nuclei (AGN) originates in a compact region called the corona located very close to the super-massive black hole and the accretion disk. The knowledge of the cut-off energy ($E_{cut}$) of the…

High Energy Astrophysical Phenomena · Physics 2019-01-30 Priyanka Rani , C. S. Stalin , K. D. Goswami

We consider the Comptonisation of the photons that make up the relativistically blurred reflection that is commonly detected from the accretion discs of AGN by the coronae of energetic particles believed to give rise to the powerful X-ray…

High Energy Astrophysical Phenomena · Physics 2015-06-23 D. R. Wilkins , L. C. Gallo

Compact radio AGN are thought to be young radio active galactic nuclei (AGN) at the early stage of AGN evolution, thus are ideal laboratory to study the high-energy emission throughout the evolution of radio AGN. In this work, we report for…

High Energy Astrophysical Phenomena · Physics 2024-01-11 Mai Liao , Junxian Wang , Jialai Kang , Xiaofeng Li , Minhua Zhou