Related papers: Variable millimetre radiation from the colliding-w…
Spectroscopic monitoring with Mercator-HERMES over the past two years reveals that MWC 314 is a massive binary system composed of an early B-type primary LBV star and a less-luminous supergiant companion. We determine an orbital period Porb…
The X-ray emission from the massive binary WR 146R is analysed in the framework of the colliding stellar wind (CSW) picture. The theoretical CSW model spectra match well the shape of the observed X-ray spectrum of WR 146R but they…
The neutral oxygen resonance 1302A line can, if the optical depth is sufficiently high, de-excite by an intercombination transition at 1641A to a metastable state. This has been noted in a number of previous studies but never systematically…
Strong wind-wind collisions in massive binaries generate a very hot plasma that frequently produces a moderately strong iron line. The morphology of this line depends upon the properties of the wind interaction zone and its orientation with…
We conducted a radial velocity survey of the Cygnus OB2 Association over a 6 year (1999 - 2005) time interval to search for massive close binaries. During this time we obtained 1139 spectra on 146 OB stars to measure mean systemic radial…
We analyze orbital solutions for 48 massive multiple-star systems in the Cygnus OB2 Association, 23 of which are newly presented here, to find that the observed distribution of orbital periods is approximately uniform in log P for P<45 d,…
We present e-MERLIN 21 cm (L-band) observations of single luminous OB stars in the Cygnus OB2 association, from the COBRaS Legacy programme. The radio observations potentially offer the most straightforward, least model-dependent,…
Context. Colliding-wind binaries are massive stellar systems featuring strong, interacting winds. These binaries may be actual particle accelerators, making them variable gamma-ray sources due to changes in the wind collision region along…
Neutron star high-mass X-ray binaries are well-studied in wavebands between the infrared and hard X-rays. Their low-frequency millimeter and radio properties, on the other hand, remain poorly understood. We present observations of the…
We present new radio and optical observations of the colliding-wind system WR146 aimed at understanding the nature of the companion to the Wolf-Rayet star and the collision of their winds. The radio observations reveal emission from three…
WR 140 is a long-period, highly eccentric Wolf-Rayet star binary system with exceptionally well-determined orbital and stellar parameters. Bright, variable X-ray emission is generated in shocks produced by the collision of the winds of the…
The winds of massive stars are important for their direct impact on the interstellar medium, and for their influence on the final state of a star prior to it exploding as a supernova. However, the dynamics of these winds is understood…
HD93129A is an O+O stellar system whose CWR has been mapped by high angular resolution observations at cm wavelengths. The synchrotron nature of the radio emission confirms its particle accelerator status. According to astrometric…
Massive colliding wind binary stars serve as laboratories for the study of strong-shock physics. In these systems fundamental flow parameters (velocities, densities, directions) are often well known, and photon fields important for Compton…
We present XMM-Newton observations of gamma^2 Velorum (WR 11, WC8+O7.5III, P = 78.53 d), a nearby Wolf-Ray binary system, at its X-ray high and low states. At high state, emission from a hot collisional plasma dominates from about 1 to 8…
The thermal radio and sub-mm emission from the winds of massive stars is investigated and the contribution to the emission due to the stellar wind acceleration region and clumping of the wind is quantified. Building upon established theory,…
After having reported the detection of X-rays emitted by the peculiar system HD5980, we assess here the origin of this high-energy emission from additional X-ray observations obtained with XMM-Newton. This research provides the first…
We present a search for excess mid-IR emission due to circumbinary material in the orbital plane of cataclysmic variables (CVs). Our motivation stems from the fact that the strong braking exerted by a circumbinary (CB) disc on the binary…
Context: Massive colliding-wind binaries (CWBs) can be non-thermal sources. The emission produced in their wind-collision region (WCR) encodes information of both the shocks properties and the relativistic electrons accelerated in them. The…
The long-term (over more than one decade) X-ray emission from two massive stellar systems known to be particle accelerators is investigated using XMM-Newton. Their X-ray properties are interpreted taking into account recent information…