Related papers: Stellar wind structures in the eclipsing binary sy…
X-Ray bursts (XRB) are powerful thermonuclear events on the surface of accreting neutron stars (NS), where nucleosynthesis of intermediate-mass elements occurs. Their predicted and observed luminosities sometimes exceed Eddington's value,…
High-Mass X-ray Binaries (HMXBs) offer a unique opportunity for the investigation of accretion onto compact objects and of wind structure in massive stars. A key source for such studies is the bright neutron star HMXB Vela X-1 whose…
The neutron star low-mass X-ray binary SWIFT J1749.4-2807 is the only known eclipsing accreting millisecond X-ray pulsar. In this manuscript we perform a spectral characterization of the system throughout its 2021, two-week-long outburst,…
A review of spectroscopic results obtained from Chandra High Energy Transmission Grating Spectrometer and XMM-Newton Reflection Grating Spectrometer observations of several wind-fed high-mass X-ray binaries (HMXBs) is presented. These…
We report on the discovery of a new X-ray pulsator, Swift J201424.9+152930 (Sw J2014). Owing to its X-ray modulation at 491 s, it was discovered in a systematic search for coherent signals in the archival data of the Swift X-ray Telescope.…
We report on an XMM-Newton observation of the accreting millisecond pulsar, IGR J17511-3057. Pulsations at 244.8339512(1) Hz are observed with an RMS pulsed fraction of 14.4(3)%. A precise solution for the P_orb=12487.51(2)s binary system…
We report on a 250 ks long X-ray observation of the supergiant fast X-ray transient (SFXT) IGR J16479-4514 performed with Suzaku in 2012 February. About 80% of the short orbital period (Porb=3.32 days) was covered as continuously as…
The orbital profile of the High Mass X-ray binary IGR J16393-4643 shows a dip in its X-ray intensity, which was previously interpreted as an eclipse. Unlike most eclipsing HMXBs, where the X-ray eclipses are about two orders of magnitude…
INTEGRAL, the European Space Agency's gamma-ray observatory, tripled the number of super-giant high-mass X-ray binaries (sgHMXB) known in the Galaxy by revealing absorbed and fast transient (SFXT) systems. In these sources, quantitative…
We present the first {\it XMM-Newton} observation of the classical supergiant high-mass X-ray binary XTE J1855$-$026 taken entirely during the eclipse of the neutron star (NS), covering the orbital phases $\phi= 0.00-0.11$. The analysis of…
We report on the \nustar{} observation of the newly discovered neutron star X-ray binary Swift~J1858.6-0814 taken on 23rd March 2019. The light curve of the source exhibits several large flares during some time intervals of this…
We describe here the nature, formation and evolution of the supergiant high mass X-ray binary (HMXB) population, i.e. systems accreting the stellar wind of supergiant stars. There are now many new observations, from the high-energy side…
We have observed the persistent but optically unidentified X-ray source X1908+075 with the PCA and HEXTE instruments on RXTE. The binary nature of this source was established by Wen, Remillard, & Bradt (2000) who found a 4.4-day orbital…
Centaurus X-3 is a persistent high-mass X-ray binary with the long-term light curve from the source exhibiting orbit-to-orbit intensity variations with no apparent superorbital periodicity. We used $\sim$13.5 years of MAXI/GSC data to study…
The late stellar evolutionary phases of low and intermediate-mass stars are strongly constrained by their mass-loss rates. The wind surrounding cool evolved stars frequently shows non-spherical features, thought to be due to an unseen…
Vela X-1 is the prototype of the class of wind-fed accreting pulsars in high mass X-ray binaries hosting a supergiant donor. We have analyzed in a systematic way ten years of INTEGRAL data of Vela X-1 (22-50 keV) and we found that when…
(abridged) We analyzed the archived XMM-Newton observation of the poorly studied low-mass X-ray binary XTE J1710-281 performed in 2004 that covered one orbital period of the system (3.8 hr). The source shows dips as well as eclipses, hence…
Thermonuclear X-ray bursts from accreting neutron stars power brief but strong irradiation of their surroundings, providing a unique way to study accretion physics. We analyze MAXI/GSC and Swift/XRT spectra of a day-long flash observed from…
The discovery of the X-ray source IGR J17252-3616 by INTEGRAL was reported on 9 February 2004. Regular monitoring by INTEGRAL shows that IGR J17252-3616 is a persistent hard X-ray source with an average count rate of 0.96 counts/s (~6.4…
Neutron stars in high-mass X-ray binaries (HMXBs) generally accrete from the wind matter of their massive companion stars. Recently Shakura et al. (2012) suggested a subsonic accretion model for low-luminosity ($<4\times 10^{36}$…