Disks originating from supernova fallback have been suggested to surround young neutron stars. Interaction between the disk and the magnetic field of the neutron star may considerably influence the evolution of the st...Disks originating from supernova fallback have been suggested to surround young neutron stars. Interaction between the disk and the magnetic field of the neutron star may considerably influence the evolution of the star through the so called propeller effect. There are many controversies about the efficiency of the propeller mechanism proposed in the literature. We investigate the faUback diskinvolved spin-down of young pulsars. By comparing the simulated and measured results of pulsar evolution, we present some possible constraints on the propeller torques exerted by the disks on neutron stars.展开更多
An observation of the Vela pulsar with the Fermi Large Area Telescope has been recently reported and the GeV light curve shows two main peaks with a phase separation of ～0.43. We study the GeV light curve using the t...An observation of the Vela pulsar with the Fermi Large Area Telescope has been recently reported and the GeV light curve shows two main peaks with a phase separation of ～0.43. We study the GeV light curve using the two-pole caustic model in which the peaks of the light curves of the pulsar result from caustic effects. The results show that the two-pole caustic model can reproduce the observed emission pattern of the two peaks and the bridge emission between them well, but overestimates the flux outside the two peaks. After taking account of the pair production effect on the azimuthal angle, we find that the resulting light curve is more consistent with the observation. We excluded the emissions from the field lines for which the distance from the null charge surface, where the pairs can be significantly produced, is larger than the radius of the light cylinder.展开更多
基金Supported by the National Natural Science Foundation of China.
文摘Disks originating from supernova fallback have been suggested to surround young neutron stars. Interaction between the disk and the magnetic field of the neutron star may considerably influence the evolution of the star through the so called propeller effect. There are many controversies about the efficiency of the propeller mechanism proposed in the literature. We investigate the faUback diskinvolved spin-down of young pulsars. By comparing the simulated and measured results of pulsar evolution, we present some possible constraints on the propeller torques exerted by the disks on neutron stars.
基金supported by the National Natural Science Foundation of China (NSFCGrantNos.10778702 and 10803005)a 973 Program (2009CB824800)
文摘An observation of the Vela pulsar with the Fermi Large Area Telescope has been recently reported and the GeV light curve shows two main peaks with a phase separation of ～0.43. We study the GeV light curve using the two-pole caustic model in which the peaks of the light curves of the pulsar result from caustic effects. The results show that the two-pole caustic model can reproduce the observed emission pattern of the two peaks and the bridge emission between them well, but overestimates the flux outside the two peaks. After taking account of the pair production effect on the azimuthal angle, we find that the resulting light curve is more consistent with the observation. We excluded the emissions from the field lines for which the distance from the null charge surface, where the pairs can be significantly produced, is larger than the radius of the light cylinder.
