Related papers: Phase-resolved XMM-Newton observations of the mass…
The X-ray emission of the O+O binary HD166734 was monitored using Swift and XMM-Newton observatories, leading to the discovery of phase-locked variations. The presence of an f line in the He-like triplets further supports a wind-wind…
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…
The O-type long-period binary HD 168112 and triple HD 167971 star systems have been known for several decades for their non-thermal synchrotron radio emission. This emission arises from relativistic electrons accelerated in the hydrodynamic…
Massive star winds are known to be responsible for X-ray emission arising from wind plasma heated by the strong shocks up to the temperature of 10$^6$--10$^7$ K in case of colliding wind binaries. We have investigated thermal and…
Mass and momentum exchanges in close massive binaries play an important role in their evolution, and produce several observational signatures such as asynchronous rotation and altered chemical compositions, that remain after the stars…
We report the analysis of an XMM-Newton observation of the close binary HD159176 (O7V + O7V). The observed L_X/L_bol ratio reveals an X-ray luminosity exceeding by a factor ~ 7 the expected value for X-ray emission from single O-stars,…
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 results of a monitoring campaign of the high-mass X-ray binary system 4U 1700-37/HD 153919, carried out with XMM-Newton in February 2001. The system was observed at four orbital phase intervals, covering 37% of one 3.41-day…
The study of the X-ray emission from massive binaries constitutes a relevant approach to investigate shock physics. The case of short period binaries may turn out to be quite challenging, especially in very asymmetric systems where the…
The long-period O-star binary system HD 168112 and the triple O-star system HD 167971 are well-known sources of non-thermal radio emission that arises from a colliding wind interaction. The wind-wind collisions in these systems should…
The members of the scarce category of Of^+ supergiants present properties that are intermediate between regular O-stars and Wolf-Rayet (WR) stars. Significant similarities between these transitional stars and WN-type objects are now clearly…
Observations with powerful X-ray telescopes, such as XMM-Newton and Chandra, significantly advance our understanding of massive stars. Nearly all early-type stars are X-ray sources. Studies of their X-ray emission provide important…
The X-ray source RX J0648.0-4418 is the only confirmed binary system in which a compact object, most likely a massive white dwarf, accretes from a hot subdwarf companion, the bright sdO star HD 49798. The X-ray emission from this system is…
Symbiotic X-ray binaries form a subclass of low-mass X-ray binary systems consisting of a neutron star accreting material from a red giant donor star via stellar wind or Roche lobe overflow. Only a few confirmed members are currently known;…
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…
HDE228766 is a very massive binary system hosting a secondary component, which is probably in an intermediate evolutionary stage between an Of supergiant and an WN star. The wind of this star collides with the wind of its O8 II companion,…
We report on the first detection of a global change in the X-ray emitting properties of a wind-wind collision, thanks to XMM-Newton observations of the massive SMC system HD5980. While its lightcurve had remained unchanged between 2000 and…
HD 149427 is a very enigmatic object. It has been classified either as a planetary nebula or as a D'-type symbiotic star. Its distance is also highly uncertain. Furthermore, HD 149427 is a potential jet source. We report the non-detection…
We present a simple analysis of X-ray emission and absorption for hot-star winds, designed to explore the natural scalings of the observed X-ray luminosity with wind and sstellar properties. We show that an exospheric approximation, in…
In latest years, the high sensitivity of the instruments on-board the XMM-Newton and Chandra satellites allowed us to explore the properties of the X-ray emission from hot subdwarf stars. The small but growing sample of X-ray detected hot…