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Related papers: The distribution of the coronal temperature in Sey…

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The focussing optics of NuSTAR have enabled high signal-to-noise spectra to be obtained from many X-ray bright Active Galactic Nuclei (AGN) and Galactic Black Hole Binaries (BHB). Spectral modelling then allows robust characterization of…

High Energy Astrophysical Phenomena · Physics 2015-05-29 A. C. Fabian , A. Lohfink , E. Kara , M. L. Parker , R. Vasudevan , C. S. Reynolds

The soft X-ray excess in the spectra of active galactic nuclei is characterized by similar electron temperatures of 0.1 -- 0.3 keV and similar photon indices around 2.2 -- 3, if fitted with inverse Comptonization. It remains a puzzle why…

High Energy Astrophysical Phenomena · Physics 2023-09-21 Norita Kawanaka , Shin Mineshige

We use a sample of 64 nearby (D=7-45 Mpc) disk galaxies including 45 AGN and 19 non-AGN, that have high spatial resolution multiline CO observations obtained with the ALMA and/or PdBI arrays to study the distribution of cold molecular gas…

Central supermassive black holes of active galactic nuclei host hot plasma with a temperature of $10^9$ K, namely coronae. Like the Sun, black hole coronae are theoretically believed to be heated by their magnetic activity, which have never…

High Energy Astrophysical Phenomena · Physics 2018-12-26 Yoshiyuki Inoue , Akihiro Doi

Data derived from general relativistic magnetohydrodynamic simulations of accretion onto black holes can be used as input to a postprocessing scheme that predicts the radiated spectrum. Combining a relativistic Compton scattering radiation…

High Energy Astrophysical Phenomena · Physics 2025-04-03 Rongrong Liu , Chris Nagele , Julian H Krolik , Brooks E Kinch , Jeremy Schnittman

Aims: The unification scheme of Seyfert galaxies predicts that the observed differences between type 1 and type 2 Seyfert galaxies are solely due to the differing orientations of the toroidal-shaped obscuring material around AGN. The…

High Energy Astrophysical Phenomena · Physics 2015-03-17 Veeresh Singh , Prajval Shastri , Guido Risaliti

We present a detailed spectral analysis of the joint XMM-Newton and NuSTAR observations of the active galactic nuclei (AGN) in the Seyfert 1.5 Galaxy ESO 362-G18. The broadband ($0.3\mbox{--}79$ keV) spectrum shows the presence of a…

High Energy Astrophysical Phenomena · Physics 2021-05-20 Yerong Xu , Javier A. García , Dominic J. Walton , Riley M. T. Connors , Kristin Madsen , Fiona A. Harrison

We present the results from a study of the X-ray variability and the near-IR to X-ray spectral energy distribution of four low-luminosity, Seyfert 1 galaxies. We compared their variability amplitude and broad band spectrum with those of…

Astrophysics · Physics 2009-11-13 I. E. Papadakis , Z. Ioannou , W. Brinkmann , E. M. Xilouris

Using a sample of 208 broad-line active galactic nuclei (AGNs) from Swift/BAT AGN Spectroscopic Survey in ultra-hard X-ray band ($14-195$ keV), the hot corona properties are investigated, i.e. the fraction of gravitational energy dissipated…

High Energy Astrophysical Phenomena · Physics 2019-06-19 Chan Wang , Li-Ming Yu , Wei-Hao Bian , Bi-Xuan Zhao

The primary X-ray emission from AGN, described by a power law, irradiates the accretion disc producing reflection features in the spectrum. The reflection features arising from the inner regions of the disc can be significantly modified by…

High Energy Astrophysical Phenomena · Physics 2020-05-20 Savithri H. Ezhikode , Gulab C. Dewangan , Ranjeev Misra , Ninan Sajeeth Philip

The corona is a key component of most luminous accreting black holes, carrying 5 - 30 % of the power and in non-jetted Active Galactic Nuclei (AGN), creating all the X-ray emission above $\simeq 1-2$ keV. Its emission illuminates the inner…

High Energy Astrophysical Phenomena · Physics 2019-03-14 Nikita Kamraj , Andrew Fabian , Anne Lohfink , Mislav Baloković , Claudio Ricci , Kristin Madsen

Accretion disk coronae are believed to account for X-ray emission in Active Galactic Nuclei (AGNs). In this paper the observed emission is assumed to be due to a population of relativistic, non-thermal electrons (e.g. produced in a flare)…

Astrophysics · Physics 2009-11-10 G. Torricelli , P. Pietrini , A. Orr

[abridged] 1H 0419-577 is a highly-accreting, luminous BLS1 AGN. This study aims to characterise its disc-corona system using, for the first time, simultaneous XMM-Newton and NuSTAR observations, performed in May and November 2018. We…

High Energy Astrophysical Phenomena · Physics 2025-08-13 Delphine Porquet , James N. Reeves , Valentina Braito

The Seyfert 1.9 galaxy MCG-05-23-016 has been shown to exhibit a complex X-ray spectrum. This source has moderate X-ray luminosity, hosts a comparably low-mass black hole, but accretes at a high Eddington rate, and allows us to study a…

The shape of the spectral energy distribution of active galaxies in the EUV--soft X-ray band (13.6 eV to 1 keV) is uncertain because obscuration by dust and gas can hamper our view of the continuum. To investigate the shape of the spectral…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 M. Meléndez , S. B. Kraemer , K. A. Weaver , R. F. Mushotzky

We present simultaneous XMM-Newton and NuSTAR observations of the `bare' Seyfert 1 galaxy, Ark 120, a system in which ionized absorption is absent. The NuSTAR hard X-ray spectral coverage allows us to constrain different models for the…

We study a model of an accretion disc surrounded by an extended corona of the temperature 10^7 - 10^8 K. This corona modifies the disk spectrum since it redirects a significant fraction of the emission from the central parts towards the…

Astrophysics · Physics 2015-06-24 A. Kurpiewski , J. Kuraszkiewicz , B. Czerny

We present the X-ray analysis of coronal properties in a statistically representative sample of 23 mostly radio-quiet AGN from the SUBWAYS campaign (SUpermassive Black holes Winds in XrAYs), focusing on quasars at redshifts $0.1 < z < 0.4 $…

We have used realistic Comptonization models to fit high quality BeppoSAX data of 6 Seyfert galaxies. Our main effort was to adopt a Comptonization model taking into account the anisotropy of the soft photon field. The most important…

Time-domain studies of active galactic nuclei (AGNs) offer a powerful tool for understanding black hole accretion physics. Prior to the optical outburst on 23 December 2017, 1ES 1927+654 was classified as a "true" type~2 AGN, an unobscured…

High Energy Astrophysical Phenomena · Physics 2024-09-17 Ruancun Li , Claudio Ricci , Luis C. Ho , Benny Trakhtenbrot , Erin Kara , Megan Masterson , Iair Arcavi
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