A Morphological Approach to the Pulsed Emission from Soft Gamma Repeaters

Abstract

We present a geometrical methodology to interpret the periodical light curves of soft gamma repeaters based on the magnetar model and the numerical arithmetic of the three-dimensional magnetosphere model for the young pulsars. The hot plasma released by the starquake is trapped in the magnetosphere, and photons are emitted tangentially to the local magnetic field lines. The variety of radiation morphologies in the burst tails and the persistent stages could be well explained by the trapped fireballs on different sites inside the closed field lines. Furthermore, our numerical results suggest that the pulse profile evolution of SGR 1806À20 during the 2004 December 27 giant flare is due to a lateral drift of the emitting region in the magnetosphere.

Suzaku Observations of SGR 1900+14 and SGR 1806-20

“…After that the stored energy may be released as bursts either through reconnection, or some sort of instability such as the thermonuclear explosions of X-ray bursts. A recent theoretical study reports that a variety of pulse morphologies can be caused by trapped fireballs released by starquakes (Jia et al 2008).…”

“…However, little has been done to elucidate the underlying physics of the pulse characteristics. A recent theoretical study suggests that the pulse characteristics may be explained by trapped fireballs produced by starquakes (Jia et al 2008).…”

Very high-frequency gravitational waves from magnetars and gamma-ray bursts

“…Lots of models of inner engine of GRBs had been proposed to explain the origin of so huge amount of energy, such as black-hole accretion, collapsar model, supernova model (see review by Piran [26]), binary neutron star mergers [34,35], black hole-neutron star mergers [36], Blandford-Znajek mechanism [37], pulsar model [26,[38][39][40][41][42][43], magnetar model [44][45][46][47], etc. Specially, the magnetar model of GRBs with fireball scenarios are studied by some previous works [48][49][50][51][52][53], and a possible case is to consider fireball trapped near the magnetar surface by the super strong magnetic fields [54][55][56][57][58][59][60]. Therefore, no matter in the case that…”

“…etc. Specially, the magnetar model of GRBs with fireball scenarios are studied by some previous works [48][49][50][51][52][53], and a possible case is to consider fireball trapped near the magnetar surface by the super strong magnetic fields [54][55][56][57][58][59][60]. Therefore, no matter in the case that GRBs source would combine magnetar as a binary system, or in the case that magnetar itself would become the source of GRBs, once such GRB radiations interact with the magnetar surface magnetic fields, it could lead to considerable generation of Gamma-HFGWs.…”

“…These models include black-hole accretion, the collapsar model, the supernova model (see review by Piran [26]), binary neutron star mergers [34,35], black hole-neutron star mergers [36], the Blandford-Znajek mechanism [37], the pulsar model [26,[38][39][40][41][42][43], the magnetar model [44][45][46], etc. In particular, the magnetar model of GRBs with fireball scenarios has been studied by some previous works [47][48][49][50][51][52], and a possible case is to consider a fireball trapped near the magnetar surface by the super strong magnetic fields [53][54][55][56][57][58][59]. Therefore, no matter whether the GRB source is a binary system with a magnetar, or whether the magnetar itself is the source of GRBs, once such GRB radiation interacts with the magnetar surface magnetic fields, it could lead to considerable generation of Gamma-HFGWs.…”