Search Publications
The nature of SS433 and the ultraluminous X-ray sources
King, A. R.; Pringle, J. E.; Begelman, M. C.
The periodic precession (162-d) and nodding (6.3-d) motions of the jets in SS433 are driven in the outer regions of the disc, whereas the jets themselves, being relativistic, are launched near the black hole at the disc centre. Given that the nutation period is comparable to the dynamical time-scale in the outer regions of the disc, it seems unlik…
V0332+53 in the outburst of 2004-2005: luminosity dependence of the cyclotron line and pulse profile
Sunyaev, R. A.; Tsygankov, S. S.; Lutovinov, A. A. +1 more
We present the results of observations of the transient X-ray pulsar V0332+53 performed during a very powerful outburst, from 2004 December to 2005 February, with the INTEGRAL and RXTE observatories in a wide (3-100 keV) energy band. A cyclotron resonance scattering line at an energy of ~26 keV has been detected in the source spectrum together wit…
Radio, X-ray, and γ-ray emission models of the colliding-wind binary WR140
Pittard, J. M.; Dougherty, S. M.
We use hydrodynamical models of the wind-collision region in the archetype colliding-wind system WR140 to determine the spatial and spectral distributions of the radio, X-ray, and γ-ray emission from shock-accelerated electrons. Our calculations are for orbital phase 0.837 when the observed radio emission is close to maximum. Using the observed th…
20-100 keV properties of cataclysmic variables detected in the INTEGRAL/IBIS survey
Hill, A. B.; Knigge, C.; Bird, A. J. +5 more
Analysis of INTEGRAL/IBIS survey observations has revealed that the rare intermediate polar and asynchronous polar cataclysmic variables (CVs) are consistently found to emit in the 20-100 keV energy band, whereas synchronous polars and the common non-magnetic CVs rarely do so. From the correlation of a candidate INTEGRAL/IBIS survey source list wi…
Constraints on dark matter and the shape of the Milky Way dark halo from the 511-keV line
Knödlseder, J.; Jean, P.; Ascasibar, Y. +1 more
About one year ago, it was speculated that decaying or annihilating light dark matter (LDM) particles could explain the flux and extension of the 511-keV line emission in the Galactic Centre. Here, we present a thorough comparison between theoretical expectations of the Galactic positron distribution within the LDM scenario and observational data …
INTEGRAL/RXTE high-energy observation of a state transition of GX 339-4
Belloni, T.; Miller, J. M.; Homan, J. +7 more
On 2004 August 15, we observed a fast (shorter than 10 h) state transition in the bright black hole transient GX 339-4 simultaneously with Rossi X-Ray Timing Explorer (RXTE) and INTEGRAL. This transition was evident both in timing and spectral properties. Combining the data from the Proportional Counter Array (PCA), the High-Energy X-ray Timing Ex…
Are GRB980425 and GRB031203 real outliers or twins of GRB060218?
Ghirlanda, G.; Ghisellini, G.; Mereghetti, S. +3 more
GRB980425 and GRB031203 are apparently two outliers with respect to the correlation between the isotropic equivalent energy Eiso emitted in the prompt radiation phase and the peak frequency Epeak of the spectrum in a νFν representation (the so-called Amati relation). We discuss if these two bursts are really differ…
INTEGRAL and XMM-Newton observations of LSI +61° 303
Walter, R.; Chernyakova, M.; Neronov, A.
LSI +61° 303 is one of the few X-ray binaries with Be star companion from which both radio and high-energy γ-ray emission have been observed. We present XMM-Newton and INTEGRAL observations which reveal variability of the X-ray spectral index of the system. The X-ray spectrum is hard (photon index Γ ~= 1.5) during the orbital phases of both high a…
The OB binary HD152219: a detached, double-lined, eclipsing system
Gosset, E.; Rauw, G.; Sana, H.
We present the results of an optical spectroscopic campaign on the massive binary HD152219 located near the core of the NGC6231 cluster. Though the primary to secondary optical brightness ratio is probably about 10, we clearly detect the secondary spectral signature and we derive the first reliable SB2 orbital solution for the system. The orbital …
INTEGRAL and XMM-Newton observations of the X-ray pulsar IGR J16320-4751/AX J1631.9-4752
Petrucci, P. -O.; Tomsick, J. A.; Rodriguez, J. +16 more
We report on observations of the X-ray pulsar IGR J16320-4751 (also known as AX J1631.9-4752) performed simultaneously with International Gamma-Ray Astrophysics Laboratory (INTEGRAL) and XMM-Newton. We refine the source position and identify the most likely infrared counterpart. Our simultaneous coverage allows us to confirm the presence of X-ray …