Related papers: Hydrostatic Expansion and Spin Changes During Type…
The Rapid Burster (MXB 1730-335) is a unique object, showing both type I and type II X-ray bursts. A type I burst of the Rapid Burster was observed with Swift/XRT on 2009 March 5, showing photospheric radius expansion for the first time in…
Observations of the cyclotron resonance scattering feature in the X-ray spectrum of GX 301-2 suggest that the surface field of the neutron star is B_CRSF ~ 4 x 10^{12}G. The same value has been derived in modelling the rapid spin-up…
Burst oscillations, a phenomenon observed in a significant fraction of Type I (thermonuclear) X-ray bursts, involve the development of highly asymmetric brightness patches in the burning surface layers of accreting neutron stars.…
Powerful Type I X-ray burst with strong radial expansion was observed from the low mass X-ray binary 4U 1820-30 with Rossi X-ray Timing Explorer on May 2, 1997. We investigate closely the flux profile during the burst expansion stage.…
Type I X-ray bursts and superbursts on neutron stars release sudden and intense radiation fields into their surroundings. Here, we consider the possible effects of these powerful explosions on the structure of the accretion disk. The goal…
The observed X-ray pulse period of OB-type high-mass X-ray binary (HMXB) pulsars are typically longer than 100 seconds. It is considered that the interaction between the strong magnetic field of neutron star and the wind matter could cause…
The outpouring of radiation during an X-ray burst can affect the properties of accretion discs around neutron stars: the corona can cool and collapse, the inner regions can be bled away due to enhanced accretion, and the additional heating…
We analyze the global hydrodynamic flow in the ocean of an accreting, rapidly rotating, non-magnetic neutron star in an LMXB during a type I X-ray burst. Our analysis takes into account the rapid rotation of the star and the lift-up of the…
We report on numerical results from a revised hydrodynamic simulation of binary neutron-star orbits near merger. We find that the correction recently identified by Flanagan significantly reduces but does not eliminate the neutron-star…
The accretion flow onto a neutron star will be impacted due to irradiation by a Type I X-ray burst. The burst radiation exerts Poynting-Robertson (PR) drag on the accretion disk, leading to an enhanced mass accretion rate. Observations of…
Some thermonuclear (type I) X-ray bursts at the neutron star surfaces in low-mass X-ray binaries take place during hard persistent states of the systems. Spectral evolution of these bursts is well described by the atmosphere model of a…
We discuss the underlying relativistic physics which causes neutron stars to compress and collapse in close binary systems as has recently been observed in numerical (3+1) dimensional general relativistic hydrodynamic simulations. We show…
Assuming the wind-fed accretion magnetars in long period X-ray pulsars, we calculated the rotational evolution of the neutron stars. Our calculations considered the effects of the magnetic field decay in magnetars. The results show that…
An analytic solution has been found in the Roche approximation for the axially symmetric structure of a hydrostatically equilibrium atmosphere of a neutron star produced by collapse. A hydrodynamic (quasione-dimensional) model for the…
X-ray observations suggest that neutron stars in low mass X-ray binaries (LMXB) are rotating with frequencies from 300 - 600 Hz. These spin rates are significantly less than the break-up rates for essentially all realistic neutron star…
We numerically solved the two-dimensional axisymmetric hydrodynamic problem of the explosion of a low-mass neutron star in a circular orbit. In the initial conditions, we assumed a nonuniform density distribution in the space surrounding…
During accretion a neutron star (NS) is spun up as angular momentum is transported through its surface layers. We study the resulting differentially rotating profile, focusing on the impact this has for type I X-ray bursts. The predominant…
We analyze several aspects of the recently noted neutron star collapse instability in close binary systems. We utilize (3+1) dimensional and spherical numerical general relativistic hydrodynamics to study the origin, evolution, and…
We present a simple spin evolution model that predicts that rapidly rotating accreting neutron stars will mainly be confined to a narrow range of spin-frequencies; P= 1.5-5 ms. This is in agreement with current observations of both neutron…
We analyze a set of Type I X-ray bursts from the low mass X-ray binary 4U 1728 -34, observed with Rossi X-ray Timing Explorer (RXTE). and we implement an analytical model of X-ray spectral formation in the neutron star (NS) atmosphere…