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We present the results of a follow-up ASCA observation and multicolour optical and near-infrared photometry carried out at the 3.5-m Italian National Telescope Galileo of SAXJ1353.9+1820. This object, serendipitously discovered by BeppoSAX…

Astrophysics · Physics 2009-10-31 C. Vignali , M. Mignoli , A. Comastri , R. Maiolino , F. Fiore

We have performed a spectroscopic study of 7 Type 2 QSOs using the mid-infrared spectrometer IRS on board the Spitzer Space Telescope. These are (to our knowledge) the first mid-IR spectra of X-ray selected QSO2s taken. The objects have…

Astrophysics · Physics 2009-11-11 E. Sturm , G. Hasinger , I. Lehmann , V. Mainieri , R. Genzel , M. D. Lehnert , D. Lutz , L. J. Tacconi

In order to find more examples of the elusive high-redshift molecular absorbers, we have embarked on a systematic discovery program for highly obscured, radio-loud "invisible AGN" using the VLA Faint Images of the Radio Sky at Twenty…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 T. Yan , J. T. Stocke , J. Darling , F. Hearty

This paper presents new X-ray observations of Mrk 231, an active galaxy of particular interest due to its large infrared luminosity and the presence of several blueshifted broad absorption line (BAL) systems, a phenomenon observed in a…

Astrophysics · Physics 2009-10-30 T. J. Turner

We present the analysis of Chandra and NuSTAR spectra of NGC 4968, a local (D$\sim$44 Mpc) 12$\mu$m-selected Seyfert 2 galaxy, enshrouded within Compton-thick layers of obscuring gas. We find no evidence of variability between the Chandra…

We performed an observational program with the X-ray satellite BeppoSAX to study objects with extreme synchrotron peak frequencies (nu_peak > 1 keV). Of the seven sources observed, four showed peak frequencies in the range 1-5 keV, while…

We have measured the X-ray spectral properties of a complete flux-limited sample of bright AGNs from HEAO-1 all-sky catalogs to investigate their statistics and provide greater constraints on the bright-end of the hard X-ray luminosity…

Astrophysics · Physics 2008-11-26 K. Shinozaki , T. Miyaji , Y. Ishisaki , Y. Ueda , Y. Ogasaka

We present the joint Chandra, XMM-Newton and NuSTAR analysis of two nearby Seyfert galaxies, NGC 3081 and ESO 565-G019. These are the only two having Chandra data in a larger sample of ten low redshift ($z \le 0.05$), candidates…

We present modeling and interpretation of the continuum and emission lines for a sample of 51 unobscured Type 1 active galactic nuclei (AGN). All of these AGNs have high quality spectra from both XMM-Newton and Sloan Digital Sky Survey…

High Energy Astrophysical Phenomena · Physics 2015-05-30 C. Jin , M. Ward , C. Done , J. M. Gelbord

XMM-Newton spectra of five red, 2MASS AGN, selected from a sample observed by Chandra to be relatively X-ray bright and to cover a range of hardness ratios, confirm the presence of substantial absorbing material in three sources with…

Astrophysics · Physics 2016-08-30 B. J. Wilkes , K. A. Pounds , G. D. Schmidt , P. S. Smith , R. M. Cutri , H. Ghosh , B. Nelson , D. C. Hines

We describe BeppoSAX observations of the black hole candidates LMC X--1 and LMC X--3 performed in Oct. 1997. Both sources can be modelled by a multicolor accretion disk spectrum, with temperature $\sim 1$ keV. However, there is some…

We report optical, radio and X-ray observations of the Narrow-Line Seyfert 1 galaxy RX J1702.5+3247. The soft (0.1-2 keV) X-ray flux, measured by BeppoSAX, is characterized by strong variability on short time scales (< 500 sec). The most…

Astrophysics · Physics 2009-11-06 M. Gliozzi , W. Brinkmann , S. A. Laurent-Muehleisen , E. C. Moran , J. Whalen

Aims: The determination of elusive redshifts of bright BL Lac objects Methods: We use the capabilities of newly available spectrograph X-Shooter at European Southern Observatory (ESO) Very Large Telescope, that combines high resolution and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Marco Landoni , Renato Falomo , Aldo Treves , Boris Sbarufatti , Roberto Decarli , Fabrizio Tavecchio , Jari Kotilainen

Very long (172 ks effective exposure time) observations of the BALQSO LBQS 2212-1759 with XMM-Newton yield a stringent upper-limit on its 0.2-10 keV (rest- frame 0.64-32.2 keV) flux, F < 6 E-17 erg/cm2/s, while simultaneous UV and optical…

Astrophysics · Physics 2009-11-11 Jean Clavel , Norbert Schartel , Laura Tomas

We report in this paper the ASCA discovery of the first radio-loud Active Galactic Nucleus (AGN) covered by a Compton-thick X-ray absorber, in the GigaHertz Peaked Spectrum (GPS) radio source OQ+208. It represents one of the few available…

Astrophysics · Physics 2007-05-23 M. Guainazzi , C. Stanghellini , P. Grandi

The giant radio galaxy M87 is the only extragalactic non-blazar object which has been detected as a source of very high energy gamma-rays. It represents a unique opportunity to study the phenomena of gamma-ray emission from a nearby AGN. In…

Astrophysics · Physics 2007-09-25 Pierre Colin

Obscured AGN are fundamental to understand the history of Super Massive Black Hole growth and their influence on galaxy formation. However, the Compton-thick AGN (NH>1e24 cm^-2) population is basically unconstrained, with less than few…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 P. Severgnini , A. Caccianiga , R. Della Ceca , V. Braito , C. Vignali , V. La Parola , A. Moretti

We report the BeppoSAX detection of a hard X-ray excess in the X-ray spectrum of the classical high-ionization Seyfert 2 galaxy Tol0109-383. The X-ray emission of this source observed below 7 keV is dominated by reflection from both cold…

Astrophysics · Physics 2009-09-17 K. Iwasawa , G. Matt , A. C. Fabian , S. Bianchi , W. N. Brandt , M. Guainazzi , T. Murayama , Y. Taniguchi

Our goal is to probe the populations of obscured and unobscured AGN investigating their optical-IR and X-ray properties as a function of X-ray flux, luminosity and redshift within a hard X-ray selected sample of 136 X-ray sources in the XMM…

Historically, the study of the central regions of Type 1 AGN has been limited by the combination of the host galaxy spectrum with strong emission from the accretion disk and NLR/BLR, which prevented us from accurately probing the galactic…

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