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We adopt a Bayesian X-ray spectral approach to investigate the accretion properties of unobscured ($20<\log(N_{\rm H}/{\rm cm}^{-2}<22$) and obscured ($22< \log(N_{\rm H}/{\rm cm}^{-2}<24$) active galactic nuclei (AGN) to shed light on the…

We show that X-ray reverberation mapping can be used to measure the distance to type 1 active galactic nuclei (AGNs). This is because X-ray photons originally emitted from the `corona' close to the black hole irradiate the accretion disc…

We present a sample of 10 low-mass active galactic nuclei (AGNs) selected from the 40-month NuSTAR serendipitous survey. The sample is selected to have robust NuSTAR detections at $3 - 24$~keV, to be at $z < 0.3$, and to have optical r-band…

Active Galactic Nuclei (AGN) are believed to be powered by accretion of matter onto a supermassive black hole. A fundamental ingredient in shaping our understanding of AGN is their variability across the entire electromagnetic spectrum.…

High Energy Astrophysical Phenomena · Physics 2025-09-08 Maurizio Paolillo , Iossif Papadakis

We present the results of X-ray spectral analysis of 22 active galactic nuclei (AGNs) with a small scattering fraction selected from the Second XMM-Newton Serendipitous Source Catalogue using hardness ratios. They are candidates of buried…

Astrophysics of Galaxies · Physics 2014-11-20 Kazuhisa Noguchi , Yuichi Terashima , Hisamitsu Awaki

In this paper, we present the hard X-ray spectral analysis of a complete sample of AGN de- tected by INTEGRAL/IBIS. In conjunction with IBIS spectra, we make use of Swift/BAT data, with the aim of cross-calibrating the two instruments,…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Manuela Molina , L. Bassani , A. Malizia , J. B. Stephen , A. J. Bird , A. Bazzano , P. Ubertini

Under the unified model for active galactic nuclei (AGNs), narrow-line (Type 2) AGNs are, in fact, broad-line (Type 1) AGNs but each with a heavily obscured accretion disk. We would therefore expect the optical continuum emission from Type…

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…

Active galactic nuclei (AGNs) are the compact, energetic central regions of galaxies, powered by supermassive black holes that accrete surrounding gas and dust. Their optical spectra can be identified by strong emission-line signatures…

Astrophysics of Galaxies · Physics 2026-01-09 Sruthi Suresh , Wei Jeat Hon , Rachel L Webster , Christian Wolf , Christopher A Onken

Active galactic nuclei (AGN) are complex phenomena. At the heart of an AGN is a relativistic accretion disk around a spinning supermassive black hole (SMBH) with an X-ray emitting corona and, sometimes, a relativistic jet. On larger scales,…

High Energy Astrophysical Phenomena · Physics 2016-05-25 Christopher S. Reynolds

Using data from the All Wavelength Extended Groth Strip International Survey (AEGIS) we statistically detect the extended X-ray emission in the interstellar medium (ISM)/intra-cluster medium (ICM) in both active and normal galaxies at 0.3…

A core sample of 59 unobscured type 1 AGNs with simultaneous XMM-Newton X-ray and UV observations is compiled from archive to probe the nature of soft X-ray excess (SE). In the first paper of this series, our focus centers on scrutinizing…

High Energy Astrophysical Phenomena · Physics 2025-03-17 Shi-Jiang Chen , Jun-Xian Wang , Jia-Lai Kang , Wen-Yong Kang , Hao Sou , Teng Liu , Zhen-Yi Cai , Zhen-Bo Su

We present deep Near-infrared (NIR) images of a sample of 19 intermediate-redshift ($0.3<z<1.0$) radio-loud active galactic nuclei (AGN) with powerful relativistic jets ($L_{1.4GHz} >10^{27}$ WHz$^{-1}$), previously classified as…

We present the X-ray analysis of the most luminous obscured active galactic nuclei (AGN) inside local ultraluminous infrared galaxies (ULIRGs). Our sample consists of ten sources, harbouring AGN components with estimated luminosity in…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 E. Nardini , G. Risaliti

We present a comprehensive long-term, multi-epoch spectral and timing study of the Seyfert 1 Active Galactic Nucleus (AGN) Mrk~1040, utilizing X-ray observations spanning from 2009 to 2024 ($\sim$15 years). The source exhibits pronounced…

High Energy Astrophysical Phenomena · Physics 2026-01-01 Prantik Nandi , Narendranath Layek , Sandip K Chakrabarti , Sachindra Naik , Priyadarshee P. Dash

We present XMM-Newton observations of three AGN taken as part of a hunt to find very heavily obscured Compton-thick AGN. For obscuring columns greater than 10^25 cm^-2, AGN are only visible at energies below 10 keV via reflected/scattered…

High Energy Astrophysical Phenomena · Physics 2015-05-28 M. L. Trippe , C. S. Reynolds , M. Koss , R. F. Mushotzky , L. M. Winter

A fraction of active galactic nuclei do not show the classical Seyfert-type signatures in their optical spectra, i.e. they are optically "elusive". X-ray observations are an optimal tool to identify this class of objects. We combine new…

We aim to study the effect of environment on the presence and fuelling of Active Galactic Nuclei (AGN) in massive galaxy clusters. We explore the use of different AGN detection techniques with the goal of selecting AGN across a broad range…

Astrophysics of Galaxies · Physics 2015-06-05 Alison J. Klesman , Vicki L. Sarajedini

We perform X-ray/ultraviolet (UV) spectral and X-ray variability studies of the radio-loud narrow-line Seyfert 1 (NLS1) galaxy RX J1633.3+4719 using XMM-Newton and Suzaku observations from 2011 and 2012. The 0.3-10 keV spectra consist of an…

High Energy Astrophysical Phenomena · Physics 2016-06-14 Labani Mallick , G. C. Dewangan , P. Gandhi , R. Misra , A. K. Kembhavi

Variability studies hold information on otherwise unresolvable regions in Active Galactic Nuclei (AGN). Population studies of large samples likewise have been very productive for our understanding of AGN. These two themes are coming…

High Energy Astrophysical Phenomena · Physics 2016-05-31 Andy Lawrence
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