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We present X-ray spectral analyses for three Seyfert 2 active galactic nuclei, NGC 424, NGC 1320, and IC 2560, observed by NuSTAR in the 3-79 keV band. The high quality hard X-ray spectra allow detailed modeling of the Compton reflection…

We present two NuSTAR observations of the local Seyfert 2 active galactic nucleus (AGN) and an ultraluminous X-ray source (ULX) candidate in NGC 5643. Together with archival data from Chandra, XMM-Newton and Swift-BAT, we perform a…

NuSTAR observatory, with its 3 - 78 keV broadband spectral coverage, enables the detections of the high-energy cutoff in a number of active galaxies, including several individual radio loud ones. In this work we present systematic and…

High Energy Astrophysical Phenomena · Physics 2020-09-29 Jia-lai Kang , Jun-xian Wang , Wen-yong Kang

We study the extensively monitored Seyfert galaxy NGC 5548 and compare its nuclear emission with models of accretion disk with accreting corona. To obtain the intrinsic nuclear spectra from the observed spectra we had to estimate and…

Astrophysics · Physics 2007-05-23 J. Kuraszkiewicz , Z. Loska , B. Czerny

We present an analysis of the 3-79 keV NuSTAR spectrum of the low-luminosity active galactic nucleus NGC 7213. In agreement with past observations, we find a lower limit to the high-energy cut-off of Ec > 140 keV, no evidence for a…

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

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 present the 3-8 keV and 8-24 keV number counts of active galactic nuclei (AGN) identified in the NuSTAR extragalactic surveys. NuSTAR has now resolved 33-39% of the X-ray background in the 8-24 keV band, directly identifying AGN with…

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 report on X-ray flares that were observed from the active galactic nucleus I Zwicky 1 (I Zw 1) in 2020 January by the NuSTAR and XMM-Newton observatories. The X-ray spectrum is well-described by a model comprised of the continuum…

High Energy Astrophysical Phenomena · Physics 2022-04-06 D. R. Wilkins , L. C. Gallo , E. Costantini , W. N. Brandt , R. D. Blandford

We report the results obtained by a systematic, broadband (0.5--150 keV) X-ray spectral analysis of moderately obscured (Compton-thin; $22 \leq \log N_{\rm H} < 24$) active galactic nuclei (AGNs) observed with Suzaku and Swift/Burst Alert…

High Energy Astrophysical Phenomena · Physics 2016-08-03 Taiki Kawamuro , Yoshihiro Ueda , Fumie Tazaki , Claudio Ricci , Yuichi Terashima

We estimate the relative contributions of the supermassive black hole (SMBH) accretion disk, corona, and obscuring torus to the bolometric luminosity of Seyfert galaxies, using Spizter mid-infrared (MIR) observations of a complete sample of…

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 sub-arcsec near-infrared 1.5 - 2.5 micron moderate resolution long-slit spectra of eight nearby Seyfert galaxies (z<0.01), both parallel to the ionization cone and perpendicular to it. These spectra complement similar data on six…

Astrophysics · Physics 2009-11-07 J. Reunanen , J. Kotilainen , M. A. Prieto

X-ray observations provide a key tool for exploring the properties of galactic coronae and their formation processes. In an earlier paper, we have presented a Chandra data analysis of the coronae of 53 nearby highly-inclined disc galaxies.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Jiang-Tao Li , Q. Daniel Wang

We present preliminary results of the spectral analysis of a large sample of Seyfert galaxies observed by BeppoSAX. The only selection criterium was a sufficiently large S/N ratio (>10) in the PDS band (12-200 keV) to allow good detection…

Astrophysics · Physics 2009-11-10 P. O. Petrucci , M. Dadina

Hard X-ray spectra of 28 bright Seyfert galaxies observed with INTEGRAL were analyzed together with the X-ray spectra from XMM-Newton, Suzaku and RXTE. These broad-band data were fitted with a model assuming a thermal Comptonization as a…

Astrophysics of Galaxies · Physics 2016-02-29 P. Lubinski , V. Beckmann , L. Gibaud , S. Paltani , I. E. Papadakis , C. Ricci , S. Soldi , M. Türler , R. Walter , A. A. Zdziarski

We use the CO band at 2.3 micron to constrain the populations of young stars in the central regions of Seyfert galaxies. We report new CO band spectroscopy of 46 Seyfert galaxies. In most cases, the observed CO indices appear diluted by the…

Hard X-ray emission in radio-quiet active galactic nuclei (AGNs) is believed to be produced via inverse Compton scattering by hot and compact coronae near the super massive black hole. However the origin and physical properties of the…

High Energy Astrophysical Phenomena · Physics 2014-03-05 Teng Liu , Jun-Xian Wang , Huan Yang , Fei-Fan Zhu , You-Yuan Zhou

Tidal Disruption Events are exotic astrophysical phenomena where matter from a star or the interstellar medium is captured by a supermassive black hole. The process liberates enormous energy, within a few months to a year timescale, enough…

High Energy Astrophysical Phenomena · Physics 2026-04-08 Arka Chatterjee , Kimitake Hayasaki , Prantik Nandi , Neeraj Kumari , Skye R. Heiland , Arghajit Jana , Sachindra Naik , Samar Safi-Harb