Related papers: Gamma Rays from colliding winds in massive binarie…
Recent reports claiming tentative association of the massive star binary system gamma^2 Velorum (WR 11) with a high-energy gamma-ray source observed by Fermi-LAT contrast the so-far exclusive role of Eta Carinae as the hitherto only…
Be/X-ray binaries are systems formed by a massive Be star and a magnetized neutron star, usually in an eccentric orbit. The Be star has strong equatorial winds occasionally forming a circumstellar disk. When the neutron star intersects the…
We present the results of extensive observations by the gamma-ray AGILE satellite of the Galactic region hosting the Carina nebula and the remarkable colliding wind binary Eta Carinae (Eta Car) during the period 2007 July to 2009 January.…
In latest years, the high sensitivity of the instruments on-board the XMM-Newton and Chandra satellites allowed us to explore the properties of the X-ray emission from hot subdwarf stars. The small but growing sample of X-ray detected hot…
Massive stars in binary systems have long been regarded as potential sources of high-energy gamma rays.The emission is principally thought to arise in the region where the stellar winds collide and accelerate relativistic particles which…
Several colliding-wind massive binaries are known to be non-thermal emitters in the radio domain. This constitutes strong evidence for the fact that an efficient particle acceleration process is at work in these objects. The acceleration…
Eta Car, with its historical outbursts, visible ejecta and massive, variable winds, continues to challenge both observers and modelers. In just the past five years over 100 papers have been published on this fascinating object. We now know…
$\gamma$ Cas stars are a $\sim$1% minority among classical Be stars with hard but only moderately strong continuous thermal X-ray flux and mostly very early-B spectral type. The X-ray flux has been suggested to originate from matter…
Consider binary system with a millisecond pulsar ejecting relativistic particles and an optical star emitting soft photons with the energy $\omega \simeq 1-10$ eV. These low-energy photons are scattered by the relativistic electrons and…
WR140 is the archetype long-period colliding wind binary (CWB) system, and is well known for dramatic variations in its synchrotron emission during its 7.9-yr, highly eccentric orbit. This emission is thought to arise from relativistic…
Colliding winds of massive star binary systems are considered as potential sites of non-thermal high-energy photon production. This is motivated merely by the detection of synchrotron radio emission from the expected colliding wind…
An X-ray study of a deeply embedded Wolf-Rayet star WR 121a has been carried out using long-term (spanning over ~12 years) archival observations from Chandra and XMM-Newton. For the first time, a periodic variation with a period of 4.1 days…
We present high resolution numerical simulations of the colliding wind system $\eta$ Carinae, showing accretion onto the secondary star close to periastron passage. Our hydrodynamical simulations include self gravity and radiative cooling.…
The colliding winds in a massive binary system generate synchrotron emission due to a fraction of electrons that have been accelerated to relativistic speeds around the shocks in the colliding-wind region. We studied the radio light curve…
We have analysed the X-ray emission from a sample of close WR+O binaries using data from the public Chandra and XMM-Newton archives. Global spectral fits show that two-temperature plasma is needed to match the X-ray emission from these…
eta Carinae is a stellar binary system with a period of 5.54 years. It harbors one of the brightest and most massive stars in our galaxy. This paper presents spectroscopic evidence for a fast (up to 2,000 km/s) X-ray outflow of ionized gas…
In the colliding-wind region of massive binaries, non-thermal radio emission occurs. This non-thermal radio emission (due to synchrotron radiation) has so far been observed at centimetre wavelengths. At millimetre wavelengths, the stellar…
We consider nebulae which are created around binary systems containing rotation powered pulsars and companion stars with strong stellar winds. It is proposed that the stellar and pulsar winds have to mix at some distance from the binary…
Three binaries are now established sources of emission at very high energies (>1e11 eV). They are composed of a massive star and a compact object. The emission can be due to the interaction of the relativistic wind from a young ms pulsar…
We present a 3D dynamical model of the orbital induced curvature of the wind-wind collision region in binary star systems. Momentum balance equations are used to determine the position and shape of the contact discontinuity between the…