Related papers: The clumpy absorber in the high-mass X-ray binary …
Broad-band spectra of accreting X-ray binary pulsars can be fit by a phenomenological model composed by a power law with a high energy rollover above 10 keV, plus a blackbody component with a temperature of few hundred eV. While, at least…
Binary systems with an accreting compact object are a unique chance to investigate the strong, clumpy, line-driven winds of early type supergiants by using the compact object's X-rays to probe the wind structure. We analyze 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…
Context: Cygnus X-1 is a black hole X-ray binary system in which the black hole captures and accretes gas from the strong stellar wind emitted by its supergiant O9.7 companion star. The irradiation of the supergiant star essentially…
The X-ray luminosity of black holes is produced through the accretion of material from their companion stars. Depending on the mass of the donor star, accretion of the material falling onto the black hole through the inner Lagrange point of…
Supergiant X-ray binaries usually comprise a neutron star accreting from the wind of a OB supergiant companion. They are classified as classical systems and the supergiant fast X-ray transients (SFXTs). The different behavior of these…
High resolution X-ray spectroscopy is a powerful tool for studying the nature of the matter surrounding the neutron star in X-ray binaries and its interaction between the stellar wind and the compact object. In particular, absorption…
High-dispersion IUE data encode significant information about aggregate line absorptions that cannot be conveniently extracted from individual spectra. We apply a new technique in which fluxes from each echelle order of a short wavelength…
In Supergiant X-ray binaries (SgXB), a compact object captures a fraction of the wind of an O/B supergiant on a close orbit. Proxies exist to evaluate the efficiency of mass and angular momentum accretion but they depend so dramatically on…
Winds are an important ingredient in the evolution of X-ray binary (XRB) systems, particularly those at high accretion rates such as ultra-luminous X-ray sources (ULXs), because they may regulate the accretion of matter onto the compact…
Recent improvements on the sensitivity and spectral resolution of X-ray observations have led to a better understanding of the properties of matter in the vicinity of High Mass X-ray Binaries hosting a supergiant star and a compact object.…
We present the results of our monitoring program to study the long-term variability of the Halpha line in high-mass X-ray binaries. We have carried out the most complete optical spectroscopic study of the global properties of high-mass…
Obscuration from clumpy accretion-disk winds has been invoked to explain the extreme X-ray weakness and X-ray variability observed in a substantial fraction of super-Eddington accreting quasars. We present a comprehensive study of the…
High-mass binaries hosting young pulsars can be powerful gamma-ray emitters. The stellar wind of the massive star in the system is expected to be clumpy. Since the high-energy emission comes from the pulsar-star wind interaction, the…
High Mass X-ray Binary Pulsars (HMXBP), in which the companion star is a source of supersonic stellar wind, provide a laboratory to probe the velocity and density profile of such winds. Here, we have measured the variation of the absorption…
The accretion of matter onto black holes and neutron stars often leads to the launching of outflows that can greatly affect the environments surrounding the compact object. In supermassive black holes, these outflows can even be powerful…
Dense wind of a massive star can be partially captured by a neutron star (NS) inside a compact binary system. Depending on the parameters of NS and the wind, the matter can penetrate the inner NS magnetosphere. At some distance from the NS…
A review of wind accretion in high-mass X-ray binaries is presented. We focus attention to different regimes of quasi-spherical accretion onto the neutron star: the supersonic (Bondi) accretion, which takes place when the captured matter…
The luminosities of ultraluminous X-ray sources (ULXs) require an exotic solution with either super-critical accretion modes onto stellar mass black holes or sub-critical accretion onto intermediate mass black holes (IMBHs) being invoked.…
Strong winds from massive stars are a topic of interest to a wide range of astrophysical fields. In High-Mass X-ray Binaries the presence of an accreting compact object on the one side allows to infer wind parameters from studies of the…