Related papers: Using X-Ray Observations to Explore the Binary Int…
We present time-resolved and phase-resolved variability studies of an extensive X-ray high-resolution spectral dataset of the $\delta$ Orionis Aa binary system. The four observations, obtained with Chandra ACIS HETGS, have a total exposure…
We report the recovery of a spectroscopic event in eta Carinae in 1997/98 after a prediction by Damineli (1996). A true periodicity with P = 2020+-5 days (0.2% uncertainty) is obtained. The line intensities and the radial-velocity curve…
X-ray appearance of normal galaxies is mainly determined by X-ray binaries powered by accretion onto a neutron star or a stellar mass black hole. Their populations scale with the star-formation rate and stellar mass of the host galaxy and…
We present in this paper a first step toward a semi-analytical treatment of the accretion process in wind-fed neutron star supergiant X-ray binaries with eccentric orbits. We consider the case of a spherically symmetric wind for the…
The eastern tip region of the Carina Nebula was observed with the Suzaku XIS for 77 ks to conduct a high-precision spectral study of extended X-ray emission. XMM-Newton EPIC data of this region were also utilized to detect point sources.…
We have monitored the massive binary star $\eta$ Carinae with the CTIO/SMARTS 1.5~m telescope and CHIRON spectrograph from the previous apastron passage of the system through the recent 2014.6 periastron passage. Our monitoring has resulted…
Three dimensional (3D) adaptive-mesh refinement (AMR) hydrodynamical simulations of the wind-wind collision between the enigmatic super-massive star \etacar and its mysterious companion star are presented which include radiative driving of…
Optical emission from actively accreting X-ray binaries is dominated by X-ray reprocessing on the outer disk. In the regime of supercritical accretion, strong radiation will power a massive wind that is optically thick and nearly spherical,…
X-ray binary accretion disk winds can carry away a significant fraction of the matter transferred from the companion and hence strongly affect the accretion flow and the long-term evolution of the binary. However, accurate mass outflow rate…
Blue shifted absorption lines from highly ionised iron are seen in some high inclination X-ray binary systems, indicating the presence of an equatorial disc wind. This launch mechanism is under debate, but thermal driving should be…
Eta Car may be the most massive and luminous star in the Galaxy and is suspected to be a massive, colliding wind binary system. The CHANDRA X-ray observatory has obtained a calibrated, high-resolution X-ray spectrum of the star…
Recent work suggests that the mass-loss rate of the primary star (Eta A) in the massive colliding wind binary Eta Carinae dropped by a factor of 2-3 between 1999 and 2010. We present results from large- (r=1545au) and small- (r=155au)…
We have made an extensive study of the UV spectrum of Eta Carinae, and find that we do not directly observe the star and its wind in the UV. Because of dust along our line of sight, the UV light that we observe arises from bound-bound…
Weakly magnetized neutron stars in X-ray binaries show complex phenomenology with several spectral components that can be associated with the accretion disk, boundary and/or spreading layer, a corona, and a wind. Spectroscopic information…
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…
High mass X-ray binaries hold the promise of giving us understanding of the structure of the winds of their supermassive companion stars by using the emission from the compact object as a backlight to evaluate the variable absorption in the…
We report Chandra ACIS-S3 x-ray imaging and spectroscopy of the R Aquarii binary system that show a spatially resolved two-sided jet and an unresolved central source. This is the first published report of such an x-ray jet seen in an…
We examine the published light curves (LCs) of 117 X-ray binary pulsars, focusing on the dependence of their light curves on the observed energy bands. It is found that the energy dependence of the LCs appears only when the X-ray luminosity…
One of the most intriguing spectral features of WR binary stars is the presence of time-dependent line profiles. Long term observations of several systems revealed the periodicity of this variability, synchronized with the orbital movement.…
A full description of the 5.5-yr low excitation events in Eta Carinae is presented. We show that they are not as simple and brief as previously thought, but a combination of two components. The first, the 'slow variation' component, is…