Search Publications
The spectral energy distribution of the central parsecs of the nearest AGN
Meisenheimer, K.; Tristram, K. R. W.; Prieto, M. A. +4 more
Spectral energy distributions (SEDs) of the central few tens of parsec region of some of the nearest, most well-studied, active galactic nuclei (AGN) are presented. These genuine AGN-core SEDs, mostly from Seyfert galaxies, are characterized by two main features: an infrared (IR) bump with the maximum in the 2-10µm range and an increasing X-…
Completing the puzzle of the 2004-2005 outburst in V0332+53: the brightening phase included
Tsygankov, S. S.; Lutovinov, A. A.; Serber, A. V.
Analysis of the data obtained with the RXTE observatory during a powerful outburst of the X-ray pulsar V0332+53 in 2004-2005 is presented. Observational data covering the outburst brightening phase are analysed in detail for the first time. A comparison of source parameters and their evolution during the brightening and fading phases shows no evid…
INTEGRAL results on supergiant fast X-ray transients and accretion mechanism interpretation: ionization effect and formation of transient accretion discs
Sidoli, L.; Ducci, L.; Paizis, A.
We performed a systematic analysis of all INTEGRAL observations from 2003 to 2009 of 14 supergiant fast X-ray transients (SFXTs), implying a net exposure time of about 30 Ms. For each source we obtained light curves and spectra (3-100 keV), discovering several new outbursts. We discuss the X-ray behaviour of SFXTs emerging from our analysis in the…
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…
The 2008 October Swift detection of X-ray bursts/outburst from the transient SGR-like AXP 1E1547.0-5408
Campana, S.; Tiengo, A.; de Luca, A. +17 more
We report on the detailed study of the 2008 October outburst from the anomalous X-ray pulsar 1E1547.0-5408 discovered through the Swift/Burst Alert Telescope (BAT) detection of soft gamma-ray repeater like short X-ray bursts on 2008 October 3. The Swift/X-ray Telescope (XRT) started observing the source after less than 100s since the BAT trigger, …
Polarized QPOs from the INTEGRAL polar IGRJ14536-5522 (=Swift J1453.4-5524)
O'Donoghue, Darragh; Buckley, David A. H.; Potter, Stephen B. +10 more
We report optical spectroscopy and high-speed photometry and polarimetry of the INTEGRAL source IGRJ14536-5522 (=Swift J1453.4-5524). The photometry, polarimetry and spectroscopy are modulated on an orbital period of 3.1564(1) h. Orbital circularly polarized modulations are seen from ~0 to ~ -18 per cent, unambiguously identifying IGRJ14536-5522 a…
Multiwavelength observations of 1RXH J173523.7-354013: revealing an unusual bursting neutron star
D'Avanzo, P.; de Luca, A.; Degenaar, N. +14 more
On 2008 May 14, the Burst Alert Telescope onboard the Swift mission triggered on a type-I X-ray burst from the previously unclassified ROSAT object 1RXH J173523.7-354013, establishing the source as a neutron star X-ray binary. We report on X-ray, optical and near-infrared observations of this system. The X-ray burst had a duration of ~2 h and belo…
The kilohertz quasi-periodic oscillations during the Z and atoll phases of the unique transient XTE J1701-462
Homan, Jeroen; Belloni, Tomaso; Wijnands, Rudy +6 more
We analysed 866 observations of the neutron star low-mass X-ray binary XTE J1701-462 during its 2006-2007 outburst. XTE J1701-462 is the only example so far of a source that during an outburst showed, beyond any doubt, spectral and timing characteristics both of the Z and atoll type. There are 707 RXTE observations (~2.5 Ms) of the source in the Z…
A new analysis of the short-duration, hard-spectrum GRB 051103, a possible extragalactic soft gamma repeater giant flare
Cline, T.; Hurley, K.; Yamaoka, K. +34 more
GRB 051103 is considered to be a candidate soft gamma repeater (SGR) extragalactic giant magnetar flare by virtue of its proximity on the sky to M81/M82, as well as its time history, localization and energy spectrum. We have derived a refined interplanetary network localization for this burst which reduces the size of the error box by over a facto…