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Related papers: X-ray Variability in the Symbiotic Binary RT Cru: …

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A cataclysmic variable is a binary system consisting of a white dwarf that accretes material from a secondary object via the Roche-lobe mechanism. In the case of long enough observation, a detailed temporal analysis can be performed,…

High Energy Astrophysical Phenomena · Physics 2015-05-13 A. A. Nucita , B. M. T. Maiolo , S. Carpano , G. Belanger , D. Coia , M. Guainazzi , F. de Paolis , G. Ingrosso

We report observations of the asynchronous polar BY Cam made using XMM-Newton. We find evidence for two accretion regions which have significantly different spectra. In both regions we find evidence for hard X-ray emission from the…

Astrophysics · Physics 2009-11-07 Gavin Ramsay , Mark Cropper

We report on an 105 ks Suzaku observation of the supernova remnant CTA 1 (G119.5+10.2). The Suzaku soft X-ray observation was carried out with both timing mode and imaging mode. A ~ 10' extended feature, which is interpreted as a bow-shock…

This paper reports the results of Suzaku observation of the spectral variation of the black hole binary LMCX-1 in the soft state. The observationwas carried out in 2009 from July 21 to 24. the obtained net count rate was $\sim$30 counts…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Shu Koyama , Shin'ya Yamada , Aya Kubota , Makoto S. Tashiro , Yukikatsu Terada , Kazuo Makishima

The nearby neutron star low-mass X-ray binary, Cen X-4, has been in a quiescent state since its last outburst in 1979. Typically, quiescent emission from these objects consists of thermal emission (presumably from the neutron star surface)…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Edward M. Cackett , Edward F. Brown , Jon M. Miller , Rudy Wijnands

We present the first in a series of papers describing the X-ray properties of a sample of 18 Seyfert 1 galaxies, using data obtained by \asca. The imaging data reveal a number of serendipitous hard X-ray sources in some source fields, but…

Astrophysics · Physics 2008-11-26 K. Nandra , I. M. George , R. F. Mushotzky , T. J. Turner , T. Yaqoob

We have monitored with the RXTE PCA the variability pattern of the 2-20 keV flux in four PG quasars (QSOs) from the Laor et al. (1994) sample. Six observations of each target at regular intervals of 1 day were performed. The sample…

Astrophysics · Physics 2009-10-31 M. Guainazzi , F. Fiore , E. Giallongo , A. Laor , M. Elvis , A. Siemiginowska

Supergiant Fast X-ray Transients (SFXTs) represent the most extreme case of X-ray variability in High Mass X-ray Binaries hosting blue supergiant companions. Mainly discovered thanks to the INTEGRAL monitoring of the Galactic plane, these…

High Energy Astrophysical Phenomena · Physics 2011-11-28 L. Sidoli

We study quantum fluctuations of the nucleon's parton densities by combining QCD factorization for hard processes with the notion of cross section fluctuations in soft diffraction. The fluctuations of the small-x gluon density are related…

High Energy Physics - Phenomenology · Physics 2008-12-18 L. Frankfurt , M. Strikman , D. Treleani , C. Weiss

We present the first Suzaku observation of the new Soft Gamma Repeater SGR 0501+4516, performed on 2008 August 26, four days after the onset of bursting activity of this new member of the magnetar family. The soft X-ray persistent emission…

NGC 3783 was observed for approximately 210ks by Suzaku and in this time showed significant spectral and flux variability at both short (20ks) and long (100ks) time scales. The full observation is found to consist of approximately six…

High Energy Astrophysical Phenomena · Physics 2015-06-03 R. C. Reis , A. C. Fabian , C. S. Reynolds , L. W. Brenneman , D. J. Walton , M. Trippe , J. M. Miller , R. F. Mushotzky , M. A. Nowak

The X-ray spectra of X-ray binaries are dominated by emission of either soft or hard X-rays which defines their soft and hard spectral states. Cygnus X-3 is amongst the list of X-ray binaries that show quite complex behavior, with various…

High Energy Astrophysical Phenomena · Physics 2021-01-20 F. Cangemi , J. Rodriguez , V. Grinberg , R. Belmont , P. Laurent , J. Wilms

X-ray spectra of accreting pulsars are generally observed to vary with their X-ray luminosity. In particular, the hardness of the X-ray continuum is found to depend on luminosity. In a few sources, the correlation between the energy of the…

High Energy Astrophysical Phenomena · Physics 2017-02-22 V. Vybornov , D. Klochkov , M. Gornostaev , K. Postnov , E. Sokolova-Lapa , R. Staubert , K. Pottschmidt , A. Santangelo

We present results from the major coordinated X-ray observing program on the ULX NGC 1313 X-1 performed in 2017, combining $XMM$-$Newton$, $Chandra$ and $NuSTAR$, focusing on the evolution of the broadband ($\sim$0.3-30.0 keV) continuum…

We present results from four new broadband X-ray observations of the extreme ultraluminous X-ray source Holmberg IX X-1 ($L_{\rm{X}} > 10^{40}$ erg/s), performed by $Suzaku$ and $NuSTAR$ in coordination. Combined with the archival data, we…

High Energy Astrophysical Phenomena · Physics 2017-05-03 D. J. Walton , F. Fuerst , F. A. Harrison , M. J. Middleton , A. C. Fabian , M. Bachetti , D. Barret , J. M. Miller , A. Ptak , V. Rana , D. Stern , L. Tao

We present the complete set of thirty four ASCA observations of non-magnetic cataclysmic variables. Timing analysis reveals large X-ray flux variations in dwarf novae in outburst (Z Cam, SS Cyg and SU UMa) and orbital modulation in high…

Astrophysics · Physics 2009-11-10 Darren S. Baskill , Peter J. Wheatley , Julian P. Osborne

We report the results from our timing analysis of 15 RXTE observations of Cygnus X-1 throughout its 1996 spectral transitions. The entire period can be divided into 3 distinct phases: (1) transition from the hard to soft state, (2) soft…

Astrophysics · Physics 2009-10-30 Wei Cui , S. N. Zhang , W. Focke , J. Swank

We present the most extensive analysis of Fourier-based X-ray timing properties of the black hole binary Cygnus X-1 to date, based on 12 years of bi-weekly monitoring with RXTE from 1999 to 2011. Our aim is a comprehensive study of timing…

Context. X-ray spectral variability analyses of active galactic nuclei (AGN) with moderate luminosities and redshifts typically show a softer when brighter behaviour. Such a trend has rarely been investigated for high-luminosity AGNs ($…

Astrophysics of Galaxies · Physics 2017-04-12 R. Serafinelli , F. Vagnetti , R. Middei

We investigate the structure of the wind in the neutron star X-ray binary system Vela X-1 by analyzing its flaring behavior. Vela X-1 shows constant flaring, with some flares reaching fluxes of more than 3.0 Crab between 20-60 keV for…

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