Related papers: Probing Colliding Wind Binaries with High-Resoluti…
WR 140 is a canonical massive "colliding wind" binary system in which periodically-varying X-ray emission is produced by the collision between the wind of the WC7 and O4-5 star components in the space between the two stars. We have obtained…
We present results of new Chandra High-Energy Transmission Grating (HETG) observations (2019 November - December) of the massive Wolf-Rayet (WR) binary WR 48a. Analysis of these high-quality data showed that the spectral lines in this…
X-ray spectroscopy is a sensitive probe of stellar winds. X-rays originate from optically thin shock-heated plasma deep inside the wind and propagate outwards throughout absorbing cool material. Recent analyses of the line ratios from…
I discuss some of the important aspects of the phenomena of colliding winds in massive binary star systems with a particular focus on WR140.
The colliding wind binary (CWB) systems \eta\ Carinae and WR140 provide unique laboratories for X-ray astrophysics. Their wind-wind collisions produce hard X-rays that have been monitored extensively by several X-ray telescopes, including…
High mass X-ray binaries hold the promise of giving us understanding of the structure of the winds of their supermassive companion stars by using the emission from the compact object as a backlight to evaluate the variable absorption in the…
Massive stars feature highly energetic stellar winds that interact whenever two such stars are bound in a binary system. The signatures of these interactions are nowadays found over a wide range of wavelengths, including the radio domain,…
Binary systems formed by early-type stars with strong winds are known to display variable non-thermal radio emission, thermal X-rays, and, at least in one case (Eta Carina), $\gamma$ rays. Some of these systems are quite eccentric and the…
The Chandra and XMM-Newton X-ray telescopes have led to numerous advances in the study and understanding of astrophysical X-ray sources. Particularly important has been the much increased spectral resolution of modern X-ray instrumentation.…
We use hydrodynamical models of the wind-collision region (WCR) in the archetype colliding-wind system WR140 to determine the spatial and spectral distribution of the radio, X-ray and gamma-ray emission from shock accelerated electrons. Our…
WR+O star binary systems exhibit synchrotron emission arising from relativistic electrons accelerated where the wind of the WR star and that of its massive binary companion collide - the wind-collision region (WCR). These ``colliding-wind''…
Gamma-ray loud X-ray binaries are binary systems that show non-thermal broadband emission from radio to gamma rays. If the system comprises a massive star and a young non-accreting pulsar, their winds will collide producing broadband…
In the colliding wind region of early-type binaries, electrons can be accelerated up to relativistic energies displaying power-law spectra, as demonstrated by the detection of non-thermal radio emission from several WR+OB systems. The…
WR 25 is a colliding-wind binary star system comprised of a very massive O2.5If*/WN6 primary and an O-star secondary in a 208-day period eccentric orbit. These hot stars have strong, highly-supersonic winds which interact to form a bright…
Bright and eclipsing, the high-mass X-ray binary Vela X-1 offers a unique opportunity to study accretion onto a neutron star from clumpy winds of O/B stars and to disentangle the complex accretion geometry of these systems. In Chandra-HETGS…
Colliding winds of massive binaries have long been considered as potential sites of non-thermal high-energy photon production. This is motivated by the detection of non-thermal spectra in the radio band, as well as by correlation studies of…
Context. Colliding wind binaries are massive systems featuring strong, interacting stellar winds which may act as particle accelerators. Therefore, such binaries are good candidates for detection at high energies. However, only the massive…
Because of its complex clumpy wind, prominent cyclotron resonant scattering features, intrinsic variability and convenient physical parameters (close distance, high inclination, small orbital separation) which facilitate the observation and…
An increasing number of early-type (O and Wolf-Rayet) colliding wind binaries (CWBs) is known to accelerate particles up to relativistic energies. In this context, non-thermal emission processes such as inverse Compton (IC) scattering are…
High-mass gamma-ray binaries are powerful nonthermal galactic sources, some of them hosting a pulsar whose relativistic wind interacts with a likely inhomogeneous stellar wind. So far, modeling these sources including stellar wind…