Related papers: Hints of gamma-ray orbital variability from gamma^…
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…
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…
The most massive binary system Eta Carinae has been recently established as a gamma-ray source by the AGILE and Fermi-LAT detectors. The high energy spectrum of this gamma-ray source is very intriguing. It shows two clear components and a…
Colliding wind binaries (CWBs) are promising sources of high-energy gamma-ray emission driven by shock acceleration of particles at wind interaction zones. The nearby CWB system $\gamma^2$ Velorum (WR 11), composed of a Wolf-Rayet (WR) and…
Colliding stellar winds in massive binary systems have been studied through their radio, optical lines and strong X-ray emission for decades. More recently, near-infrared spectrointerferometric observations have become available in a few…
We report on the first multi-color precision light curve of the bright Wolf-Rayet binary $\gamma^2$ Velorum, obtained over six months with the nanosatellites in the BRITE- Constellation fleet. In parallel, we obtained 488 high-resolution…
Recent reports claiming association of the massive star binary system $\gamma^2 $Velorum (WR 11) with a high-energy $\gamma$-ray source observed by \textit{Fermi}-LAT contrast the so-far exclusive role of $\eta$ Carinae as the hitherto only…
Observations of high energy gamma rays recently revealed a persistent source in spatial coincidence with the binary system Eta Carinae. Since modulation of the observed gamma-ray flux on orbital time scales has not been reported so far, an…
The binary system eta Carinae has completed its first 5.54y orbit since the beginning of science operation of the Fermi Large Area Telescope (LAT). We are now able to investigate the high-energy gamma-ray source at the position of eta…
The binary system gamma-2 Velorum (WC8+O7.5) contains the nearest known Wolf-Rayet star to the Sun, at a distance of 258$_{-31}^{+41}$ pc. Its strong radio emission shows evidence for a partially absorbed nonthermal component, which has…
The $\eta$ Carinae binary system is the first $\gamma$-ray binary ever observed which does not contain a compact object. The dense wind of the primary star shocks against the fast light wind coming from the companion star, creating the…
$\eta$ Carinae is a colliding wind binary hosting two of the most massive stars and featuring the strongest wind collision mechanical luminosity. The wind collision region of this system is detected in X-rays and $\gamma$-rays and offers a…
The {\eta} Carinae binary system hosts the most massive stars with the highest known mass-loss rate. Its dense wind encounters the faster wind expelled by the companion, dissipating mechanical energy in the shock, accelerating particles up…
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…
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…
Eta Carinae is the colliding wind binary with the largest mass loss rate in our Galaxy and the only one in which hard X-ray emission has been detected. Eta Carinae is therefore a primary candidate to search for particle acceleration by…
The massive binary system Eta Carinae and the surrounding HII complex, the Carina Nebula, are potential particle acceleration sites from which very-high-energy (VHE; E > 100 GeV) \gamma-ray emission could be expected. This paper presents…
There are only a few sources that are definitely known to be gamma-ray binaries. Two of these are listed as associations in the Fermi LAT Bright Source List. We are developing novel techniques to extract high signal-to-noise light curves of…
We present a new analysis of an archived Chandra HETGS X-ray spectrum of the WR+O colliding wind binary Gamma Velorum. The spectrum is dominated by emission lines from astrophysically abundant elements: Ne, Mg, Si, S and Fe. From a…
Gamma-ray binaries emit most of their radiated power beyond ~10 MeV. The non-thermal emission is thought to arise from the interaction of the relativistic wind of a rotation-powered pulsar with the stellar wind of its massive (O or Be)…