The energy-dependent gamma-ray light curves and spectra of the Vela pulsar in the dissipative magnetospheres

Abstract

We study the pulsar energy-dependent $\gamma$-ray light curves and spectra from curvature radiation in the dissipative magnetospheres. The dissipative magnetospheres with the combined force-free (FFE) and Aristotelian (AE) are computed by a pseudo-spectral method with the high-resolution simulation in the rotating coordinate system, which produces a near force-free field structure with the dissipative region only near the equatorial current sheet outside the light cylinder (LC). We use the test particle trajectory method to compute the energy-dependent $\gamma$-ray light curves, phase-average and phase-resolved spectra by including both the accelerating electric field and radiation reaction. The predicted energy-dependent $\gamma$-ray light curves and spectra are then compared with those of the Vela pulsar observed by Fermi. Our results can generally reproduce the observed trends of the energy-dependent $\gamma$-ray light curves and spectra for the Vela pulsar.