Related papers: Do we see accreting magnetars in X-ray pulsars?
The surface magnetic field strength of millisecond pulsars (MSPs) is found to be about 4 orders of magnitude lower than that of garden variety radio pulsars (with a spin of $\sim 0.5-5$ s and $B\sim 10^{12}$G). The exact mechanism of the…
The intense magnetic fields present in neutron stars are closely linked to their observed temperature and spectral characteristics, timing properties, including spin period and its derivatives. Therefore, a comprehensive theoretical…
Soft gamma repeaters and anomalous x-ray pulsars form a rapidly increasing group of x-ray sources exhibiting sporadic emission of short bursts. They are believed to be magnetars, i.e. neutron stars powered by extreme magnetic fields,…
Anomalous X-ray Pulsars and Soft Gamma-Ray Repeaters have been generally recognized as neutron stars with super strong magnetic fields, namely "magnetars". The "magnetars" manifest that the luminosity in X-ray band are larger than the…
Magnetars are the strongest magnets in the present universe and the combination of extreme magnetic field, gravity and density makes them unique laboratories to probe current physical theories (from quantum electrodynamics to general…
We have shown previously that many of the properties of persistent accretion-powered millisecond pulsars can be understood if their X-ray emitting areas are near their spin axes and move as the accretion rate and structure of the inner disk…
Magnetars form a special population of neutron stars with strong magnetic fields and long spin periods. About 30 magnetars and magnetar candidates known currently are probably isolated. But the possibility that magnetars are in binaries…
Magnetars, neutron stars with ultra strong magnetic fields ($B\sim 10^{14} - 10^{15}$G), manifest their exotic nature in the form of soft gamma-ray repeaters and anomalous X-ray pulsars. This study estimates the birthrate of magnetars to be…
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…
Quasi-spherical accretion in wind-fed X-ray pulsars is discussed. At X-ray luminosities <4 10^{36} erg/s, a hot convective shell is formed around the neutron star magnetosphere, and subsonic settling accretion regime sets in. In this…
The evolutionary scenario of the neutron star magnetic field is examined assuming a spindown-induced expulsion of magnetic flux originally confined to the core, in which case the expelled flux undergoes ohmic decay. The nature of field…
The nearby isolated neutron stars are a group of seven relatively slowly rotating neutron stars that show thermal X-ray spectra, most with broad absorption features. They are interesting both because they may allow one to determine…
Anomalous X-ray pulsars and soft gamma repeaters have recently emerged as a unified class of neutron stars, identified by dramatic X-ray and gamma-ray outbursts and via luminous X-ray pulsations, both thought to be powered by the decay of…
Magnetic field estimates for nearby isolated neutron stars (INS) help to constrain both the characteristics of the population and the nature of their peculiar X-ray spectra. From a series of XMM-Newton observations of RX J2143.0+0654, we…
Observations of the X-ray pulsar 4U 2206+54, performed over a 15-year span, show its period, which is now 5555 \pm 9 s, to increase drastically. Such behavior of the pulsar can be hardly explained in the frame of traditional scenarios of…
Strongly magnetized, accreting neutron stars show periodic and aperiodic variability over a wide range of time scales. By obtaining spectral and timing information on these different time scales, we can have a closer look into the physics…
We studied possible evolution of the rotational period and the magnetic field of the X-ray source RX J0720.4-3125 assuming this source to be an isolated neutron star accreting interstellar medium. Magnetic field of the source is estimated…
Neutron stars feature extremely high magnetic fields with deduced field strengths of $10^{15}$ G in the case of magnetars and potentially much higher values inside of the star. In this context we consider the appearance of $\rho^-$ meson…
Accreting millisecond X-ray pulsars are known to provide a wealth of physical information during their successive states of outburst and quiescence. Based on the observed spin-up and spin-down rates of these objects it is possible, among…
The theory of quasi-spherical subsonic accretion onto magnetized rotating neutron star is reviewed. Different regimes of quasi-spherical accretion onto a neutron star: supersonic (Bondi) accretion, which takes place when the captured matter…