Corequake Model of Pulsar Glitches for Neutron Stars with Pion-Condensed Core

From the viewpoint that combined (charged plus neutral) pion condensates come into play·in the core of massive «1.4 -1.6)Mo ) neutron stars, a possible explanation for the remarkable difference in glitches of Vela and Crab pulsars is given by applying a new version of corequake model to Vela glitches. Occurrence of pion condensation (PC) much affects the properties of dense neutron matter. In addition to a remarkable softening of the equation of state (EOS), the following two points are notable. en Neutral pion condensation (NPC) causes a solid-like state of nucleons with one-dimensional localization and specific spin-isospin ordering, namely, the Alternating Layer Spin (ALS) structure proposed by Tamiya, Tatsumi and present authors,2) which we call "ALS solid". (ii) Charged pion conden sation (CPC) strongly enhances a neutrino emissivity and provides an efficient cooling mechanism,3) which we call "pion cooling". If PC is realized in the core of some neutron stars (NS), it gives rise to rather drastic change in such aspects of NS as the structure, cooling, glitches and so forth. In this paper, we study glitch problem from the standpoint that these aspects are closely related to each other in the pion condensed NS. Our aim here is to show that a combined condensation of CPC and NPC provides us with an interesting possibility to understand the remarkable difference observed in glitch phenomena between the Vela and the Crab pulsars. Combined PC and its effects on NS