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Related papers: Active Galactic Nuclei: present observations and p…

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In this paper we discuss the broad-band X-ray characteristics of a complete sample of 36 type 1 AGN, detected by INTEGRAL in the 20-40 keV band above the 5.5sigma level. We present, for all the objects in the sample, the broad-band (1-110…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 M. Molina , L. Bassani , A. Malizia , J. B. Stephen , A. J. Bird , A. J. Dean , F. Panessa , A. De Rosa , R. Landi

In this second research note of a series of two, we present the first near-infrared results we obtained when modeling Active Galactic Nuclei (AGN). Our first proceedings showed the comparison between the MontAGN and STOKES Monte Carlo…

Astrophysics of Galaxies · Physics 2016-10-18 F. Marin , L. Grosset , R. Goosmann , D. Gratadour , D. Rouan , Y. Clénet , D. Pelat , P. Andrea Rojas Lobos

Axion-like particles (ALPs) are compelling candidates for dark matter and potential portals to new physics beyond the Standard Model. Photons traversing magnetized regions can convert into ALPs, producing characteristic, energy-dependent…

High Energy Astrophysical Phenomena · Physics 2026-01-23 Denys Malyshev , Lidiia Zadorozhna , Yuriy Bidasyuk , Andrea Santangelo , Oleg Ruchayskiy

Black-hole binaries are important sources through which studying accretion onto compact objects. In the X/gamma-ray domain, these objects show several and complex spectral behaviours and transitions. Based on INTEGRAL observations collected…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Melania Del Santo

Hard X-ray surveys like those provided by IBIS and BAT on board the INTEGRAL and Swift satellites list a significant number of sources which are unidentified and/or unclassified and which deserve multiwaveband observations to be properly…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 Pietro Parisi

We present the results of a program to identify so far unknown active nuclei (AGN) in galaxies. Candidate galactic nuclei have been selected for optical spectroscopy from a cross-correlation of the ROSAT all sky survey (RASS) bright source…

Astrophysics · Physics 2007-05-23 K. Bischoff , W. Pietsch , T. Boller , S. Döbereiner , W. Kollatschny , H. -U. Zimmermann

Active galactic nucleus (AGN)-driven gas outflows are one of the best tracers of AGN feedback in action, as these powerful outflows expel/heat or compress the surrounding interstellar medium (ISM), thus quenching or enhancing star-forming…

Astrophysics of Galaxies · Physics 2026-02-10 Ruisong Xia , Chen Qin , Huynh Anh N. Le , Yongquan Xue , Shifu Zhu , Mengqiu Huang , Hao Liu , Xiaozhi Lin

Interband lags in the optical continua of active galactic nuclei (AGN) have been observed over years of monitoring, yet their physical origins remain unclear. While variable interband lags have been found in a few individual AGN…

Astrophysics of Galaxies · Physics 2025-07-08 Zhen-Bo Su , Zhen-Yi Cai , Hengxiao Guo , Mouyuan Sun , Jun-Xian Wang

Short-term variability of X-ray spectra has been reported for several Active Galactic Nuclei. Significant X-ray flux variations are observed within time scales down to 10^4 -- 10^5 seconds. We discuss short variability time scales in the…

Astrophysics · Physics 2007-05-23 R. W. Goosmann , B. Czerny , A. -M. Dumont , M. Mouchet , A. Rozanska , V. Karas , M. Dovciak

Optical spectroscopic identification of the nature of 21 unidentified southern hard X-ray objects is reported here in the framework of our campaign aimed at determining the nature of newly-discovered and/or unidentified sources detected by…

We report on Chandra observations of 18 hard X-ray (>20 keV) sources discovered with the INTEGRAL satellite near the Galactic plane. For 14 of the INTEGRAL sources, we have uncovered one or two potential Chandra counterparts per source.…

High Energy Astrophysical Phenomena · Physics 2015-06-05 John A. Tomsick , Arash Bodaghee , Sylvain Chaty , Jerome Rodriguez , Farid Rahoui , Jules Halpern , Emrah Kalemci , Mehtap Ozbey Arabaci

Active Galactic Nuclei (AGN) have long been known to be variable, but the amplitude, timescale and nature of these changes can often differ dramatically from object to object. The richest source of information about the properties of AGN…

Astrophysics of Galaxies · Physics 2021-07-14 Hartmut Winkler

We consider a sample of type-I active galactic nuclei (AGN) that were observed by Chandra/HETG and resulted in high signal-to-noise grating spectra, which we study in detail. All objects show signatures for very high ionization outflows.…

Astrophysics · Physics 2008-12-19 Doron Chelouche

In this work we present the most comprehensive INTEGRAL AGN sample which lists 272 objects. Here we mainly use this sample to study the absorption properties of active galaxies, to probe new AGN classes and to test the AGN unification…

High Energy Astrophysical Phenomena · Physics 2015-06-05 A. Malizia , L. Bassani , A. Bazzano , A. J. Bird , N. Masetti , F. Panessa , J. B. Stephen , P. Ubertini

The inter-band lags among the optical broad-band continua of active galactic nuclei (AGNs) have been intensively explored over the past decade. However, the nature of the lags remains under debate. Here utilizing two distinct scenarios for…

During the last 10 years, INTEGRAL made a unique contribution to the study of accreting millisecond X-ray pulsars (AMXPs), discovering three of the 14 sources now known of this class. Besides increasing the number of known AMXPs, INTEGRAL…

High Energy Astrophysical Phenomena · Physics 2013-02-13 M. Falanga , L. Kuiper , J. Poutanen , D. K. Galloway , E. Bozzo , A. Goldwurm , W. Hermsen , L. Stella

A new sample of hard X-ray sources in the Galactic Plane is being revealed by the regular observations performed by the INTEGRAL satellite. The full characterization of these sources is mandatory to understand the hard X-ray sky. Here we…

Astrophysics · Physics 2007-05-23 J. A. Combi , M. Ribo , J. Marti , S. Chaty

Active galactic nuclei (AGN) are one of the most luminous objects in the Universe, emitting powerful continuum and line emission across all wavelength bands. They represent an important link in the investigations of the galaxy evolution and…

We studied spectra for 34 accretion-powered X-ray and one millisecond pulsars that were within the field of view of the INTEGRAL observatory over two years (December 2002 - January 2005) of its in-orbit operation and that were detected by…

Astrophysics · Physics 2007-05-23 E. V. Filippova , S. S. Tsygankov , A. A. Lutovinov , R. A. Sunyaev

We present results on approximately one year of INTEGRAL observations of six AGN detected during the regular scans of the Galactic Plane. The sample is composed by five Seyfert 2 objects (MCG -05-23-16, NGC 4945, the Circinus galaxy, NGC…

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