Related papers: WR146 - observing the OB-type companion
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 eccentric WR+O binary system WR 140 produces dust for a few months at intervals of 7.94 yrs coincident with periastron passage. We present the first resolved images of this dust shell, at binary phases ~0.039 and ~0.055, using aperture…
The high luminosity of massive, early-type stars drives strong stellar winds through line scattering of the stars continuum radiation. Their momenta contribute substantially to the dynamics and energetics of the ambient interstellar medium…
We present a model for atmospheric wind circulation in binary millisecond pulsar (MSP) companions, showing how the optical light curve (LC) and radial velocities (RV) are sensitive to the wind flow, causing LC orbital phase shifts and…
During the summer of 2013, a 4-month spectroscopic campaign took place to observe the variabilities in three Wolf-Rayet stars. The spectroscopic data have been analyzed for WR 134 (WN6b), to better understand its behaviour and long-term…
In this work the thermal emission over cm to sub-mm wavelengths from the winds in short-period O+O-star binaries is investigated (potential non-thermal emission is presently ignored). The calculations are based on three-dimensional…
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…
The Wolf-Rayet star WR 46 is known to exhibit a very complex variability pattern on relatively short time scales of a few hours. Periodic but intermittent radial velocity shifts of optical lines as well as multiple photometric periods have…
We have compiled a list of 36 O+O and 89 Wolf-Rayet binary candidates in the Milky Way and Magellanic clouds detected with the Chandra, XMM-Newton and ROSAT satellites to probe the connection between their X-ray properties and their system…
We report the discovery of variability in the X-ray emission from the Wolf-Rayet type star WR 65. Using archival Chandra data spanning over 5 yr we detect changes of the X-ray flux by a factor of 3 accompanied by changes in the X-ray…
A primary goal of the FUSE mission is to understand the origin of the O VI ion in the interstellar medium of the Galaxy and the Magellanic Clouds. Along sightlines to OB-type stars, these interstellar components are usually blended with O…
This thesis discusses the influence of magnetic fields on the instability of line-driven winds in O-stars and Wolf-Rayet stars. This combination is an important concept to understand the strong, observed winds from Wolf-Rayet stars. In the…
The article presents the results of the analysis of optical light curves of the massive binary system WR 20a (WN 6ha + WN 6ha). The analysis was performed with the binary system model, extending the standard Roche model for the case when…
We present the results of an intensive campaign of spectroscopic and photometric monitoring of the peculiar Wolf-Rayet star WR 134 from 1989 to 1997. This unprecedentedly large data set allows us to confirm unambiguously the existence of a…
Wolf-Rayet (WR) 140 is the archetypal periodic dust-forming colliding-wind binary that hosts a carbon-rich WR (WC) star and an O-star companion with an orbital period of 7.93 years and an orbital eccentricity of 0.9. Throughout the past…
We present the results of a systematic search for large-scale spectroscopic variability in apparently single Wolf-Rayet stars brighter than ~12.5. In this first paper we characterize the various forms of variability detected and distinguish…
Determining accurate orbits of binary stars with powerful winds is challenging. The dense outflows increase the effective photospheric radius, precluding direct observation of the Keplerian motion; instead the observables are broad lines…
Observations with the Infrared Space Observatory (ISO) SWS spectrometer are used to constrain the velocity law and wind clumping of the well-studied Wolf-Rayet (WR) star WR 136 (HD 192163) (WN6). Because the free-free continuum opacity in…
The winds of stars with very specific temperatures and luminosities are ideal for determining the magnitude and nature of mass loss in OB stars. I identify these stars and analyze their wind lines. The results are discussed within the…
Most types of massive stars display X-ray emission that is affected by the properties of their stellar winds. Single non-magnetic OB stars have an X-ray luminosity that scales with their bolometric luminosity and their emission is thought…