Related papers: Interactions of Type I X-ray Bursts with Thin Accr…
The aim of this paper is to investigate the transition of a strongly magnetized neutron star into the accretion regime with very low accretion rate. For this purpose we monitored the Be-transient X-ray pulsar GRO J1008-57 throughout a full…
A brief overview is given of the observations of accretion disks in X-ray binaries, discussing their geometry, their effect on the rotation period of the accreting object, their optical and X-ray spectra, time variability, and radio…
Type I X-ray bursts are thermonuclear flashes on the surface of accreting neutron stars, involving hundreds of nuclei and thousands of reactions with larger uncertainties in reaction rate. To investigate the impact of nuclear reaction rate…
The Rossi X-ray Timing Explorer has detected nearly coherent oscillations in the tails of type I X-ray bursts from 17 low-mass X-ray binaries. The oscillations are thought to be generated by brightness fluctuations associated with a surface…
The dynamics of the plasma in the inner regions of an accretion disk around accreting millisecond X-ray pulsars is controlled by the magnetic field of the neutron star. The interaction between an accretion disk and a strong magnetic field…
X-ray light curves of three X-ray pulsars, SMC X-1, LMC X-4 and Her X-1, folded with their respective super-orbital periods, are shown to be well reproduced by a model in which X-rays from a compact object towards us are periodically…
The inner part of a thin accretion disk around a Kerr black hole can serve as an important tool to study the physics of the strong gravity regime. A tilt in such a disk with respect to the black hole spin axis is particularly useful for…
We measured the thermonuclear burning efficiency as a function of accretion rate for the Type I X-ray bursts of five low-mass X-ray binary systems. We chose sources with measured neutron star spins and a substantial population of bursts…
We re-examine the possibility of an astrophysically allowed KSVZ-type axion that has a strongly suppressed coupling to photons. We then investigate the impact of such ''hadronic axions'' on two classes of astrophysical objects: black hole…
I construct a simple model of the convective burning layer during a type I X-ray burst to investigate the effects convection has on the stability of the layer to nonradial oscillations. A linear perturbation analysis demonstrates that the…
The coronae in X-ray binaries (XRBs) still remain poorly understood, although they have been believed for a long time to play a key role in modeling the characteristic outbursts of XRBs. Type-I X-ray bursts, the thermonuclear flashes…
Type-I X-ray bursts arise from unstable thermonuclear burning of accreted fuel on the surface of neutron stars. In this chapter we review the fundamental physics of the burning processes, and summarise the observational, numerical, and…
Type I X-ray bursts are produced by thermonuclear runaways that develop on accreting neutron stars. Once one location ignites, the flame propagates across the surface of the star. Flame propagation is fundamental in order to understand…
Type I X-ray bursts (XRBs) are thermonuclear runaways on the surface of accreting neutron stars, powered by rapid proton-capture and alpha-capture processes on neutron-deficient nuclei. Uncertainties in the corresponding reaction rates…
We investigate whether triggering of the magnetorotational instability (MRI) in protoplanetary discs can account for the wide diversity of observed accretion outbursts. We show that short-lived, relatively low accretion rate events probably…
We present evidence of a direct accretion disk-jet connection in the Galactic microquasar GRS 1915+105 based on our analysis of RXTE/PCA data with a ``spike'' in X-ray light curves. We find that the radio emission increases as the hardness…
It is well known that low mass young stellar objects (LMYSOs) gain a significant portion of their final mass through episodes of very rapid accretion, with mass accretion rates up to $\dot M_* \sim 10^{-4} M_{\odot}$~yr$^{-1}$. Recent…
Gas falling quasi-spherically onto a black hole forms an inner accretion disc if its specific angular momentum $l$ exceeds $\lmin\sim r_gc$ where $r_g$ is the Schwarzschild radius. The standard disc model assumes $l\gg\lmin$. We argue that,…
The X-ray spectra of accreting stellar-mass black hole systems exhibit spectral features due to reflection, especially broad iron K alpha emission lines. We investigate the reflection by the accretion disc that can be expected in the…
Although during the last decade new observations and new theoretical results have brought better understanding of the physics of accretion onto compact objects, many old and several new questions and problems await answers and solutions. I…