Magnetospheric structure and non-thermal emission of axps and sgrs

Nov, 2001
4 pages
Published in:
  • ASP Conf.Ser. 271 (2002) 262
e-Print:

Citations per year

20002001200202
Abstract: (arXiv)
In the framework of the magnetar model for the Soft Gamma Repeaters and Anomalous X-ray Pulsars, we consider the structure of neutron star magnetospheres threaded by large-scale electrical currents. We construct self-similar, force-free equilibria under the assumption of axisymmetry and a power law dependence of magnetic field on radius, Br(2+p){\bf B} \propto r^{-(2+p)}. A large-scale twist of the field lines softens the radial dependence to p<1p < 1, thereby accelerating the spindown torque with respect to a vacuum dipole. A magnetosphere with a strong twist (Bϕ/Bθ=O(1)B_\phi/B_\theta = O(1) at the equator) has an optical depth 1\sim 1 to resonant cyclotron scattering, independent of frequency (radius), surface magnetic field strength, or the charge/mass ratio of the scattering charge. We investigate the effects of the resonant Compton scattering by the charge carriers (both electrons and ions) on the emergent X-ray spectra and pulse profiles.