Related papers: Understanding the X-ray luminosity function of hig…
A low mass X-ray binary (LMXB) contains either a neutron star or a black hole accreting materials from its low mass companion star. It is one of the primary astrophysical sources for studying the stellar size compact objects and the…
We present a measure of the hard (2-8 keV) X-ray luminosity function (XLF) of Active Galactic Nuclei up to z~5. At high redshifts, the wide area coverage of the Chandra Multiwavength Project is crucial to detect rare and luminous (Lx >…
We use deep Chandra imaging to measure the distribution of X-ray luminosities (L_X) for samples of star-forming galaxies as a function of stellar mass and redshift, using a Bayesian method to push below the nominal X-ray detection limits.…
Low-mass X-ray binaries (LMXBs), which occur in old stellar populations, have velocities exceeding those of their parent distribution by at least 20 km/s. This makes them ideal probes for dark matter, in particular in dwarf spheroidals…
A neutron star low-mass X-ray binary is a binary stellar system with a neutron star and a low-mass companion star rotating around each other. In this system the neutron star accretes mass from the companion, and as this matter falls into…
X-ray sources in spiral galaxies can be approximately classified into bulge and disk populations. The bulge (or hard) sources have X-ray colors which are consistent with Low Mass X-ray Binaries (LMXB) but the the disk sources have softer…
X-ray luminosity ($L_X$) originating from high-mass X-ray binaries (HMXBs) is tightly correlated with the host galaxy's star-formation rate (SFR). We explore this connection at sub-galactic scales spanning ${\sim}$7 dex in SFR and ${\sim}$8…
In this proof-of-concept study we demonstrate that in a binary system mass can be transferred toward an accreting compact object at extremely high rate. If the transferred mass is efficiently converted to X-ray luminosity (with disregard of…
(abridged) A detailed comparison is performed of the LFs compiled at infrared, radio and optical wavelengths and converted into XLFs using available relations with the XLF directly estimated in the 0.5--2 keV energy band from X-ray surveys…
High-mass X-ray binaries are fundamental in the study of stellar evolution, nucleosynthesis, structure and evolution of galaxies and accretion processes. Hard X-rays observations by INTEGRAL and Swift have broad- ened significantly our…
We present an X-ray binary population synthesis model, and use it to simulate the evolution of X-ray binaries formed in a burst of star formation of duration 20 Myr and star-formation rate 10 M_sun/yr. Our goal is to explain the hard (2-10…
Binary star systems represent a significant proportion of the Galactic stellar population, with X-ray binaries being an important subset of these for high energy astrophysics. Although hundreds of X-ray binaries are detected in the Milky…
Eclipsing binaries provide one of the most direct mechanisms for measuring stellar properties such as mass and radius, but historically, determining these properties has been non-trivial and computationally prohibitive. As such, only a…
We identify and quantify the set of constraints that neutron star-normal star binaries must satisfy in order to become observable LMXBs. These constraints are related to (i) the thermal and hydrostatic equilibrium of the donors, (ii) the…
We present a short overview of the properties of faint Galactic X-ray binaries. We place emphasis on current classification scenarios. One of the important parameters for the faint sources is their intrinsic luminosity. In the case of…
Binary stars have long been considered to play a crucial role in globular cluster evolution, and offer the advantages of studying systems at the same, well-determined distances. However, early search attempts were consistently thwarted by…
We construct the rest-frame 2--10 keV intrinsic X-ray luminosity function of Active Galactic Nuclei (AGNs) from a combination of X-ray surveys from the all-sky Swift BAT survey to the Chandra Deep Field-South. We use ~3200 AGNs in our…
Be/X-ray binaries comprise roughly two-thirds of the high-mass X-ray binaries (HMXBs), which is a class of X-ray binaries that results from the high mass of the companion or donor star (> 10 solar masses). Currently the formation and…
We have developed a clumpy stellar wind model for OB supergiants in order to compare predictions of this model with the X-ray behaviour of both classes of persistent and transient High Mass X-ray Binaries (HMXBs).
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…