相关论文: Quenching of the accretion disk strong aperiodic v…
Active Galactic Nuclei (AGN) are generally considered as the scaled-up counterparts of X-ray binaries (XRBs). It is known that the power spectral density (PSD) of the X-ray emission of XRBs shows significant evolution with spectral states.…
Accretion discs around black holes power some of the most luminous objects in the Universe. Discs that are misaligned to the black hole spin can become warped over time by Lense-Thirring precession. Recent work has shown that strongly…
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…
We analyzed 39 ks NuSTAR observation data of the high mass X-ray binary Cen X-3 in order to investigate the orbital- and spin-phase spectral variability. The observation covers the orbital phase of $\Phi=0.199$-$0.414$ of the source, where…
The accretion flow within the magnetospheric radius of bright X-ray pulsars can form an optically thick envelope, concealing the central neutron star from the distant observer. Most photons are emitted at the surface of a neutron star and…
By performing 2.5-dimensional general relativistic radiation magnetohydrodynamic simulations, we demonstrate supercritical accretion onto a non-rotating, magnetized neutron star, where the magnetic field strength of dipole fields is…
Millisecond x-ray pulsars have weak magnetic dipole moments of $\sim 10^{16}$\,T\,m$^3$ compared to ordinary X-ray pulsars with dipole moments of $10^{20}$\,T\,m$^3$. For this reason a surrounding accretion disc can extend closer to the…
The Rossi X-Ray Timing Explorer (RXTE) has found that the neutron stars in low-mass X-ray binaries exhibit oscillations in the range 300-1200 Hz. Persistent emission may exhibit one or both of two features. In bursts a nearly coherent…
The Galactic microquasar GRS 1915+105 shows rich variability which is categorized into different classes. In this paper, we report temporal and spectral analysis of GRS 1915+105 to study the properties of the accretion flow when the light…
We investigate further a model of the accreting millisecond X-ray pulsars we proposed earlier. In this model, the X-ray-emitting regions of these pulsars are near their spin axes but move. This is to be expected if the magnetic poles of…
We propose a physical model for the peaked noise in the X-ray power density spectra of accreting X-ray binaries. We interpret its appearance as an interference of two Comptonization continua: one coming from the up-scattering of seed…
A neutron star in binary orbit with a low-mass non-degenerate companion becomes a source of x-rays with millisecond variability when mass accretion spins it up. Centrifugally driven changes in density profile may initiate a phase transition…
Rotation-powered millisecond radio pulsars have been spun up to their present spin period by a $10^8$ - $10^9$ yr long X-ray-bright phase of accretion of matter and angular momentum in a low-to-intermediate mass binary system. Recently, the…
We argue that X-ray flaring variability observed in the transient X-ray pulsar A 0535+26 is due to low-mode magnetospheric instability. This instability develops at the onset of accretion, in the thin boundary layer between the accretion…
The intense X-ray emission from coronae and accretion shocks in young PMS stars is likely to play an important role in the evolution and dispersal of circumstellar disks. Several aspects of the physics of this X-ray emission remain…
Accretion onto magnetized neutron stars is expected to be centrifugally inhibited at low accretion rates. Several sources, however, are known to pulsate in quiescence at luminosities below the theoretical limit predicted for the onset of…
We report the discovery of coupling between periodic and aperiodic variability and ~12-mHz X-ray quasi-periodic oscillations (QPOs) from the X-ray binary pulsar Her X-1 using data from the Rossi X-Ray Timing Explorer. We found two different…
The dramatic discovery with the Rossi X-Ray Timing Explorer satellite of remarkably coherent $\sim$300--1200 Hz oscillations in the X-ray brightness of some sixteen neutron stars in low-mass binary systems has spurred theoretical modeling…
Quasi-spherical subsonic accretion can be realized in slowly rotating wind-fed X-ray pulsars (XPSRs) at X-ray luminosities <4 10^{36} erg/s. In this regime the accreting matter settles down subsonically onto the rotating magnetosphere,…
A millisecond pulsar is a neutron star that has been substantially spun up by accretion from a binary companion. A previously unrecognized factor governing the spin evolution of such pulsars is the crucial effect of non-steady or transient…