English
Related papers

Related papers: The Phoenix galaxy: UGC4203 re-birth from its ashe…

200 papers

From the literature, we construct from literature a sample of 25 Seyfert 2 galaxies (S2s) with a broad line region detected in near infrared spectroscopy and 29 with NIR BLR which was detected. We find no significant difference between the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Hong-bing Cai , Xin-Wen Shu , Zhen-Ya Zheng , Jun-xian Wang

The 1.5 Seyfert galaxy NGC 3227 has been observed by several X-ray missions. We carried out a combined analysis of the data obtained by more recent major observations of the source: two observations performed by XMM-Newton in 2000 and 2006…

Astrophysics of Galaxies · Physics 2022-07-26 J. Newman , S. Tsuruta , A. C. Liebmann , H. Kunieda , Y. Haba

We show that the sharp cutoff in the hard X-ray spectrum of NGC 4151, unusual for Seyfert 1 galaxies, can be reconciled with the average Seyfert 1 spectrum if we assume that the central source is completely hidden from our line of sight by…

Astrophysics · Physics 2009-10-28 Juri Poutanen , Marek Sikora , Mitchell C. Begelman , Pawel Magdziarz

X-ray unabsorbed Seyfert 2 galaxies appear to have X-ray absorption column densities that are too low (NH < 10^22 cm-2) to explain the absence of broad emission lines in their optical spectra, challenging the standard AGN unification model.…

High Energy Astrophysical Phenomena · Physics 2011-05-25 Xing-Xing Huang , Jun-Xian Wang , Ying Tan , Huan Yang , Ya-Fang Huang

We discuss the importance of X-ray scattering and Compton reflection in type-2 Seyfert galaxies, based upon the analysis of ASCA observations of 25 such sources. Consideration of the iron Kalpha, [O III] line and X-ray variability suggest…

Astrophysics · Physics 2009-10-30 T. J. Turner , I. M. George , K. Nandra , R. F. Mushotzky

The Seyfert 2 galaxy Mrk 1210 was found to exhibit a flat hard X-ray component by ASCA, although ASCA could not distinguish whether it is an absorbed direct component or a reflected one. We then observed Mrk 1210 with BeppoSAX, and found…

Astrophysics · Physics 2015-06-24 Masanori Ohno , Yasushi Fukazawa , Naoko Iyomoto

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…

We describe a complete volume limited sample of nearby active galaxies selected by their 14-195keV luminosity, and outline its rationale for studying the mechanisms regulating gas inflow and outflow. We describe also a complementary sample…

Cen X-3 is a compact, high-mass X-ray binary (HMXRB), likely powered by Roche lobe overflow. We present a phase-resolved X-ray spectral and timing analysis of a target of opportunity \textit{Chandra} observation made during a low-flux to…

Using the BeppoSAX observatory, we have observed a nearby LINER/Seyfert 2 galaxy, NGC 3079, which is known as an outflow galaxy and a bright H_2O-maser source. Using the PDS detector, we have revealed that the NGC 3079 nucleus suffers from…

Astrophysics · Physics 2007-05-23 Naoko Iyomoto , Yasushi Fukazawa , Naomasa Nakai , Yuko Ishihara

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

Mrk 590 was originally classified as a Seyfert 1 galaxy, but then it underwent dramatic changes: the nuclear luminosity dropped by over two orders of magnitude and the broad emission lines all but disappeared from the optical spectrum. Here…

Chandra observations of the core of the nearby starburst galaxy NGC 253 reveal a heavily absorbed source of hard X-rays embedded within the nuclear starburst region. The source has an unabsorbed, 2 to 10 keV luminosity of >=10^39 erg/s and…

Astrophysics · Physics 2009-11-07 Kimberly Weaver , Timothy Heckman , David Strickland , Michael Dahlem

We present the results of the broadband X-ray spectral analysis of simultaneous NuSTAR and XMM-Newton observations of four nearby Compton-thick active galactic nuclei (AGN) candidates selected from the Swift-Burst Alert Telescope (BAT)…

We selected a sample of eight bright unobscured (at least at the iron line energy) Seyfert Galaxies observed simultaneously by XMM-Newton and BeppoSAX, taking advantage of the complementary characteristics of the two missions. The main…

Astrophysics · Physics 2009-11-10 S. Bianchi , G. Matt , I. Balestra , M. Guainazzi , G. C. Perola

Aims. We present a 0.2--200 keV broad-band study of absorbed AGN observed with INTEGRAL, XMM-Newton, Chandra and ASCA to investigate the continuum shape and the absorbing/reflecting medium properties. Methods. The sources are selected in…

Astrophysics · Physics 2009-11-13 A. De Rosa , L. Bassani , P. Ubertini , F. Panessa , A. Malizia , A. J. Dean , R. Walter

We have carried out a systematic analysis of the nearby (z=0.0279) active galaxy Zw 229.015 using multi-epoch, multi-instrument and deep pointed observations with XMM-Newton, Suzaku, Swift and NuSTAR. Spectral and temporal variability are…

High Energy Astrophysical Phenomena · Physics 2019-07-31 S. Tripathi , S. G. H. Waddell , L. C. Gallo , W. F. Welsh , C-Y. Chiang

We present a sample of 17 type 2 Seyfert galaxies which have an X-ray column density lower than 10^{22} cm^{-2}. The Compton thin nature of these sources is strongly suggested by isotropic indicators. We estimate the fraction of these…

Astrophysics · Physics 2009-11-07 Francesca Panessa , Loredana Bassani

We develop a self-consistent model of Seyfert galaxies continuum emission. High energy emission is produced by Inverse Compton process on soft photons emitted as thermal radiation by the accretion disk. Thermal emission is, at turn,…

Astrophysics · Physics 2009-10-30 P. O. Petrucci , G. Henri , J. Malzac , E. Jourdain

We report the discovery of RX J2317.8-4422 in an extremely low X-ray flux state by the Neil Gehrels Swift observatory in 2014 April/May. In total, the low-energy X-ray emission dropped by a factor 100. We have carried out multi-wavelength…

‹ Prev 1 4 5 6 7 8 10 Next ›