A powerful e^{+-} outflow driven by a proto-strange quark star

Abstract

An electron-positron layer can cover the surface of a bare strange star (SS), the electric field in which can excite the vacuum and drive a pair wind by taking away the heat of the star. In order to investigate the pair emission ability of a proto-SS, we establish a toy model to describe its early thermal evolution, where the initial trapping of neutrinos is specially taken into account. It is found that the early cooling of the SS is dominated by the neutrino diffusion rather than the conventional Urca processes, which leads to the appearance of an initial temperature plateau. During this plateau phase, the surface e^{+-} pair emission can keep a constant luminosity of 10^{48}-10^{50} erg s^{-1} for about a few to a few tens of seconds, which is dependent on the value of the initial temperature. The total energy released through this e^{+-} wind can reach as high as 10^{51} erg. In principle, this pair wind could be responsible for the prompt emission or extended emission of some gamma-ray bursts.