Related papers: A new look at Anomalous X-ray Pulsars
Using recently calculated analytic models for the thermal structure of ultramagnetized neutron stars, we estimate the thermal fluxes from young ($t\sim 1000$ yr) ultramagnetized ($B \sim 10^{15}$ G) cooling neutron stars. We find that the…
Accretion onto neutron stars (NSs) in X-ray pulsars (XRPs) results in intense X-ray emission, and under specific conditions, high-energy nuclear interactions that produce gamma-ray photons at discrete energies. These interactions are…
Thermal emission from the surface of an ultramagnetic neutron star is believed to contribute significantly to the soft X-ray flux of the Anomalous X-ray Pulsars. We compare the detailed predictions of models of the surface emission from a…
In the settling accretion theory, which is applicable to quasi-spherical accreting slowly rotating magnetized neutron stars with X-ray luminosity $L_x\lesssim 4\times 10^{36}$~erg/s, bright X-ray flares ($\sim 10^{38}-10^{40}$~ergs)…
Compact steady sources of X-ray emission have been detected at the positions of at least two soft gamma-ray repeaters (SGRs). These sources have been interpreted as synchrotron nebulae powered by the neutron star that is causing the bursts.…
We report on long-term monitoring of anomalous X-ray pulsars (AXPs) using the Rossi X-ray Timing Explorer (RXTE). Using phase-coherent timing, we find a wide variety of behaviors among the sources, ranging from high stability (in 1E…
I review the rotation measurements of accreting neutron stars. Many of the highly magnetic accreting X-ray pulsars have been continuously observed with the Burst and Transient Source Experiment (BATSE) aboard the Compton Gamma-Ray…
We consider a simple scenario for the accretion of matter onto a neutron star in order to understand processes in the inner pulsar magnetosphere during the transition stage between different accretion modes. A simple quasi-spherical…
In the fallback disk model for the persistent emission of Anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs), the hard X-ray emission arises from bulk- and thermal Comptonization of bremsstrahlung photons, which are…
Energy losses from isolated neutron stars are commonly attributed to the emission of electromagnetic radiation from a rotating point-like magnetic dipole in vacuum. This emission mechanism predicts a braking index $n=3$, which is not…
The quiescent emission of the anomalous X-ray pulsar (AXP) 4U 0142+61 extends over a broad range of energy, from radio up to hard X-rays. In particular, this object is unique among soft gamma-ray repeaters (SGRs) and AXPs in presenting…
The surface temperatures as well as X-ray luminosities of Anomalous X-ray Pulsars and Soft Gamma Repeaters are several times higher than that of the ordinary isolated neutron stars at similar ages. We present a simple approach to explain…
The appearance of subsonic propellers situated in a strong wind is discussed. We show that it is similar to the appearance of anomalous X-ray pulsars (AXPs) provided the mass and the magnetic moment of neutron stars are 1.4 solar masses,…
Anomalous X-ray pulsars (AXPs) and soft gamma repeaters (SGRs) are two small classes of X-ray sources strongly suspected to host a magnetar, i.e. an ultra-magnetized neutron star with $B\approx 10^14-10^15 G. Many SGRs/AXPs are known to be…
Currently used model of spherical accretion onto a magnetized rotating neutron star encounters major difficulties in explaining the entry rate of accreting material into the stellar field and spin evolution of long-period X-ray pulsars.…
Anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs) are magnetar candidates, i.e., neutron stars powered by strong magnetic field. If they are indeed magnetars, they will emit high-energy gamma-rays which are detectable by…
The concept of a "magnetar" was proposed mainly because of two factors. First, the X-ray luminosity of Anomalous X-ray Pulsars (AXPs) and Soft Gamma-Ray Repeaters (SGRs) is larger than the rotational energy loss rate, and second, the…
We present the results from the analysis of the broad-band X-ray spectra of 5 Anomalous X-ray Pulsars (AXPs) and Soft $\gamma$-ray Repeaters (SGRs). We fit their Suzaku and INTEGRAL spectra with models appropriate for the X-ray emission…
We examine properties of thermal radiation emitted by strongly magnetized neutron stars (NSs). In particular, we show that the pulsation amplitudes of the energy-integrated flux are an increasing function of the absorption column density to…
We propose a model to account for the bursts from soft gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs) in which quantum electrodynamics (QED) plays a vital role. In our theory, that we term ``fast-mode breakdown,''…