Search Publications
3D models of radiatively driven colliding winds in massive O + O star binaries - III. Thermal X-ray emission
Pittard, J. M.; Parkin, E. R.
The X-ray emission from the wind-wind collision in short-period massive O + O star binaries is investigated. The emission is calculated from 3D hydrodynamical models which incorporate gravity, the driving of the winds, orbital motion of the stars and radiative cooling of the shocked plasma. Changes in the amount of stellar occultation and circumst…
Relativistic disc reflection in the extreme NLS1 IRAS13224-3809
Brandt, W. N.; Ponti, G.; Fabian, A. C. +7 more
We present a spectral variability study of the XMM-Newton and Suzaku observations of one of the most extreme narrow-line Seyfert 1 galaxies, IRAS13224-3809. The X-ray spectrum is characterized by two main peculiar features: (i) a strong soft excess with a steep rise below about 1.3 keV and (ii) a deep drop in flux above 8.2 keV. Although absorptio…
Deriving an X-ray luminosity function of dwarf novae based on parallax measurements
Mukai, K.; Osborne, J. P.; Thorstensen, J. R. +1 more
We have derived an X-ray luminosity function using parallax-based distance measurements of a set of 12 dwarf novae, consisting of Suzaku, XMM-Newton and ASCA observations. The shape of the X-ray luminosity function obtained is the most accurate to date, and the luminosities of our sample are concentrated between ~1030 and 1031
Spectral variability and reverberation time delays in the Suzaku X-ray spectrum of NGC 4051
Turner, T. J.; Kraemer, S. B.; Crenshaw, D. M. +3 more
Long-exposure Suzaku X-ray observations of the nearby active galaxy NGC 4051 from 2005 and 2008 are analysed, in an attempt to reach a self-consistent understanding of both the spectral variability on long time-scales and the broad-band variability at high time resolution. The techniques of principal components analysis and a maximum likelihood me…
Metal transport by gas sloshing in M87
Böhringer, H.; Simionescu, A.; Churazov, E. +5 more
We present the results of an XMM-Newton mosaic covering the central ~200kpc of the nearby Virgo cluster. We focus on a strong surface brightness discontinuity in the outskirts of the brightest cluster galaxy (BCG), M87. Using both XMM-Newton and Suzaku, we derive accurate temperature and metallicity profiles across this feature and show that it is…
Extreme flux states of NGC 4151 observed with INTEGRAL
Paltani, S.; Walter, R.; Ferrigno, C. +5 more
We present a comprehensive spectral analysis of all INTEGRAL data obtained so far for the X-ray-bright Seyfert galaxy NGC 4151. We also use all contemporaneous data from RXTE, XMM-Newton, Swift and Suzaku. We find a linear correlation between the medium- and hard-energy X-ray fluxes measured by INTEGRAL, which indicates an almost constant spectral…
Hard X-ray properties of magnetic cataclysmic variables
Hill, A. B.; Knigge, C.; Bird, A. J. +10 more
Hard X-ray surveys have proven remarkably efficient in detecting intermediate polars and asynchronous polars, two of the rarest type of cataclysmic variable (CV). Here, we present a global study of hard X-ray-selected intermediate polars and asynchronous polars, focusing particularly on the link between hard X-ray properties and spin/orbital perio…
Explaining the hard excesses in active galactic nuclei
Fabian, A. C.; Reis, R. C.; Walton, D. J.
A common model invoked to describe the X-ray spectra of active galaxies includes a relativistically blurred reflection component, which in some cases can be the dominant contributor to the received flux. Alternative interpretations are often based around complex absorption, and to date it has proven difficult to determine between these two viable …
Evidence for a truncated accretion disc in the low-luminosity Seyfert galaxy, NGC 7213?
Turner, T. J.; Porquet, D.; Reeves, J. N. +4 more
We present the broad-band 0.6-150keV Suzaku and Swift BAT spectra of the low-luminosity Seyfert galaxy, NGC 7213. The time-averaged continuum emission is well fitted by a single power law of photon index Γ = 1.75, and from consideration of the Fermi flux limit we constrain the high-energy cut-off to be 350keV < Ecut < 25MeV. Line …
The longest observation of a low-intensity state from a supergiant fast X-ray transient: Suzaku observes IGRJ08408-4503
Sidoli, L.; Esposito, P.; Ducci, L.
We report here on the longest deep X-ray observation of a supergiant fast X-ray transient (SFXT) outside outburst, with an average luminosity level of 1033 erg s-1 (assuming 3 kpc distance). This observation was performed with Suzaku in 2009 December and was targeted on IGRJ08408-4503, with a net exposure with the X-ray Imagi…