Related papers: Point-wise Self-similar Solution for Spiral Shocks…
We present the results of three-dimensional numerical simulations of mass transfer in semi-detached binary systems in which the mass-losing star is rotating. The cases of aligned and misaligned non-synchronous rotation of the donor star are…
Outflows are common in many astrophysical systems which contain black holes and neutron stars. Difference between stellar outflows and outflows from these systems is that the outflows in these systems have to form out of the inflowing…
X-ray binaries, as bright local sources with short variability timescales for a wide range of accretion processes, represent ideal targets for high-resolution X-ray spectroscopy. In this chapter, we present a high-resolution X-ray spectral…
Thanks to extensive observations with X-ray missions and facilities working in other wavelengths, as well as rapidly--advancing numerical simulations of accretion flows, our knowledge of astrophysical black holes has been remarkably…
We perform high-resolution, grid-based hydrodynamics simulations of gaseous rings viscously spreading into disks around equal-mass, circular binaries. We find that all systems suppress accretion onto the binary when the gas is relatively…
We investigate the formation of binary stellar systems. We consider a model where a `seed' protobinary system forms, via fragmentation, within a collapsing molecular cloud core and evolves to its final mass by accreting material from an…
Compact binaries have long been a paradigm for accretion theory. Much of our present view of how accretion occurs comes directly from the comparison of theory with observations of these sources. Since theory differs little for other objects…
We present an instability occurring in the inner part of disks threaded by a moderately strong vertical (poloidal) magnetic field. Its mechanism is such that a spiral density wave in the disk, driven by magnetic stresses (rather than…
We study mass ejection from accretion disks formed in the merger of a white dwarf with a neutron star or black hole. These disks are mostly radiatively-inefficient and support nuclear fusion reactions, with ensuing outflows and…
Stellar-mass binary black holes may have circumbinary disks if formed through common-envelope evolution or within gaseous environments. Disks can drive binaries into wider and more eccentric orbits, while gravitational waves harden and…
We investigated accretion on to black holes in presence of viscosity and cooling, by employing an equation of state with variable adiabatic index and multi-species fluid. We obtained the expression of generalized Bernoulli parameter which…
The advent of the new generation of X-ray telescopes yielded a significant step forward in our understanding of ionised absorption generated in the accretion discs of X-ray binaries. It has become evident that these relatively weak and…
Observations suggest that many, if not all, post AGB systems evolve through an aspherical outflow phase. Such outflows require a sufficient engine rotational energy which binaries can provide. Via common envelope evolution, binaries can…
We propose that the recently discovered luminous hypersoft X-ray sources can be explained by accretion onto a binary black hole in a hierarchical triple system. For black hole masses $\sim 15 M_\odot$, the orbital separation of the internal…
We establish the evolution equations of the set of independent variables characterizing the 2PN rigorous conservative dynamics of a spinning compact binary, with the inclusion of the leading order spin-orbit, spin-spin and mass quadrupole -…
By performing two-dimensional axisymmetric general relativistic radiation magnetohydrodynamics simulations with spin parameter $a^*$ varying from -0.9 to 0.9, we investigate the dependence on the black hole spin of the energy flow from…
Three-dimensional hydrodynamic calculations are performed in order to investigate mass transfer in a close binary system, in which one component undergoes mass loss through a wind. The mass ratio is assumed to be unity. The radius of the…
We extend our previous studies of head-on collisions of boson stars by considering orbiting binary boson stars. We concentrate on equal mass binaries and study the dynamical behavior of boson/boson and boson/antiboson pairs. We examine the…
Recent SPH simulations by Martin et al. (2014) suggest a circumstellar gaseous disk may exhibit coherent eccentricity-inclination oscillations due to the tidal forcing of an inclined binary companion, in a manner that resembles Lidov-Kozai…
We performed 3D MHD calculations of stream accretion in cataclysmic variable stars for which the white dwarf primary star possesses a strong and complex magnetic field. These calculations are motivated by observations of polars; cataclysmic…