相关论文: On the Quasi-Periodic Oscillations of Magnetars
The discovery of quasi-periodic oscillations (QPOs) in magnetar giant flares has opened up prospects for neutron star asteroseismology. However, with only three giant flares ever recorded, and only two with data of sufficient quality to…
Quasi-Periodic Oscillations (QPOs) have been observed during three powerful magnetar flares, from SGR0526-66, SGR1806-20 and SGR1900+14. These QPOs have been commonly interpreted as being driven by the mechanical modes of the magnetar's…
We propose a scenario for the quasi-periodic oscillations observed in magnetar flares wherein a tangled component of the stellar magnetic field introduces nearly isotropic stress that gives the fluid core of the star an effective shear…
The highly tangled magnetic field of a magnetar supports shear waves similar to Alfv\'en waves in an ordered magnetic field. Here we explore if torsional modes excited in the stellar interior and magnetosphere can explain the quasi-periodic…
In this study we propose a new generic model for QPOs based on oscillation modes of neutron star magnetospheres. We argue that the interaction of the accretion disk with the magnetosphere can excite resonant shear Alfven waves in a region…
Magnetars are neutron stars with superstrong magnetic fields. Some of them (soft-gamma repeaters, SGRs) demonstrate gigantic flares which nature is still unclear. At decay phase of such flares one often observes quasi-periodic oscillations…
We consider torsional oscillations of magnetars. This problem features rich dynamics due to the strong interaction between the normal modes of a magnetar's crust and a continuum of Magneto-Hydro-Dynamic (MHD) modes in its fluid core. We…
We investigate the oscillation spectrum of rotating Newtonian neutron stars endowed with purely toroidal magnetic fields, using a time evolution code to evolve linear perturbations in the Cowling approximation. The background star is…
Quasi-periodic oscillations (QPOs) observed in the giant flares of magnetars are of particular interest due to their potential to open up a window into the neutron star interior via neutron star asteroseismology. However, only three giant…
Quasi-periodic oscillations have been seen in the light curves following several magnetar giant flares. These oscillations are of great interest as they probably provide our first ever view of the normal modes of oscillation of neutron…
Soft gamma-ray repeaters (SGRs) are widely understood as slowly rotating isolated neutron stars. Their generally large spin-down rates, high magnetic fields, and strong outburst energies render them different from ordinary pulsars. In a few…
We discuss torsional oscillations of highly magnetised neutron stars (magnetars) using two-dimensional, magneto-elastic-hydrodynamical simulations. Our model is able to explain both the low- and high-frequency quasi-periodic oscillations…
It has recently been suggested that the maximum observed quasi-periodic oscillation (QPO) frequencies, $\nu_{max}$, for several low-mass X-ray binaries, particularly 4U 1820-30, correspond to the orbital frequency at the inner-most stable…
The quasi-periodic oscillations (QPOs) observed in the tails of magnetar giant $\gamma$-ray flares have long been interpreted as normal oscillation modes of these stars. However, most studies modelling QPOs have neglected some key features…
This is the second of a series of papers aimed to look for an explanation on the generation of high frequency quasi-periodic oscillations (QPOs) in accretion disks around neutron star, black hole, and white dwarf binaries. The model is…
We suggest a plausible interpretation for the twin kiloHertz quasi-periodic oscillations (kHz QPOs) in neutron star low-mass X-ray binaries. We identify the upper kHz QPO frequencies to be the rotational frequency and the lower kHz QPOs the…
We report on the numerical discovery of quasi-periodic oscillations (QPOs) associated with accretion through a non-axisymmetric magnetic boundary layer in the unstable regime, when two ordered equatorial streams form and rotate…
When an accreting star is close to rotational equilibrium between the dipole component of the stellar magnetic field and the accretion disk, the star's rotation rate is roughly of the order of the Keplerean rotation rate at the inner…
Magneto-elastic oscillations of neutron stars are believed to explain observed quasi-periodic oscillations (QPOs) in the decaying tail of the giant flares of highly magnetized neutron stars (magnetars). Strong efforts of the theoretical…
The quasiperiodic oscillations found in the three giant flares of soft gamma-ray repeaters observed to date have been interpreted as crustal oscillations caused by a starquake following a dramatic rearrangement of the stellar magnetic…