Related papers: Exploring the connection between the stellar wind …
The properties of the orbit and the donor star in the high mass X-ray binary microquasar LS 5039 indicate that accretion processes should mainly occur via a radiatively driven wind. In such a scenario, significant X-ray variability would be…
The binary LS 5039 is a non-thermal X-ray emitter that presents jet-like radio structures, and is also one of the most misterious TeV sources in our Galaxy. The presence of an O-type star in LS 5039 implies that the non-thermal emitter must…
There is much evidence to suggest that stellar wind capture, rather than Roche lobe overflow, serves as the accretion mechanism onto the compact secondary object in the massive X-ray binary LS 5039. The lack of significant emission combined…
LS~5039 is a powerful gamma-ray binary that probably hosts a non-accreting pulsar. Despite the wealth of data available, the power source of the non-thermal emitter is still unknown. We use a dynamical-radiative numerical model and…
We present an investigation of new optical and ultraviolet spectra of the mass donor star in the massive X-ray binary LS 5039. The optical band spectral line strengths indicate that the atmosphere is N-rich and C-poor, and we classify the…
Gamma-ray binaries are systems containing a massive star and a compact object that have been detected up to TeV energies. The high energy emission could result from particle acceleration in the region where the stellar wind from the massive…
LS 5039 hosts a high-mass star, and a compact object that might be a strongly magnetized neutron star (NS). This scenario requires a mechanism to power its persistent and strong nonthermal emission. We investigate a mechanism in which the…
LS 5039 is a high-mass binary with a period of 4 days, containing a compact object and an O star, one of the few high-mass binaries detected in gamma-rays. Our Chandra ACIS observation of LS 5039 provided a high-significance (~10sigma)…
Gamma-ray binary systems, a subclass of high-mass X-ray binaries, show non-thermal emissions from radio to TeV. While efficient electron acceleration is considered to take place in them, the nature of the acceleration mechanism and the…
Context. We have presented a numerical model for the non-thermal emission of gamma-ray binaries in a pulsar-wind driven scenario. Aims. We apply this model to one of the best-observed gamma-ray binaries, the LS 5039 system. Methods. The…
LS 5039 is an X-ray binary that presents non-thermal radio emission. The radiation at $\sim 5$ GHz is quite steady and optically thin, consisting on a dominant core plus an extended jet-like structure. There is a spectral turnover around 1…
Gamma-ray binaries are systems that emit non-thermal radiation peaking at energies above 1 MeV. One proposed scenario to explain their emission consists of a pulsar orbiting a massive star, with particle acceleration taking place in shocks…
Our dedicated XMM-Newton monitoring, as well as archival Chandra and Swift datasets, were used to examine the behaviour of the WN5h+O3V binary WR21a at high energies. For most of the orbit, the X-ray emission exhibits few variations.…
Mass-loss from massive stars is fundamental to stellar and galactic evolution and enrichment of the interstellar medium. Reliable determination of mass-loss rate is dependent upon unravelling details of massive star outflows, including…
We have recently studied LS 5039, a gamma-ray binary, with Giant Meterwave Radio Telescope (GMRT) during its periastron and apastron passage. The results presented here show that the spectra are inverted at the low frequency and the flux…
Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. To clarify the systematics of the observed X-ray properties, we have analyzed a large series of Chandra and XMM observations,…
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…
LS 5039 and LSI +61 303 are unique amongst high-mass X-ray binaries (HMXB) for their spatially-resolved radio emission and their counterpart at >GeV gamma-ray energies, canonically attributed to non-thermal particles in an accretion-powered…
PSR B1259-63 is a 48 ms radio pulsar in a highly eccentric 3.4 year orbit with a Be star SS 2883. Unpulsed gamma-ray, X-ray and radio emission components are observed from the binary system. It is likely that the collision of the pulsar…
LS 5039 is a TeV gamma-ray binary with extended radio emission. It consists of a compact object in the mildly eccentric (e=0.35), 3.9-day orbit around a massive O star. The nature of the compact object is not yet established. In this paper,…