THERMALLY DRIVEN NEUTRON-STAR GLITCHES

We examine the thermal and dynamical response of a neutron star to a s udden perturbation of the inner crust temperature. During the star's e volution, starquakes and other processes may deposit greater than or s imilar to 10(42) ergs, causing significant internal heating and increa sed frictional coupling between the crust and the more rapidly rotatin g neutron superfluid the star is expected to contain. Through numerica l simulation we study the propagation of the thermal wave created by t he energy deposition, the induced motion of the interior superfluid, a nd the resulting spin evolution of the crust. We find that energy depo sitions of similar to 10(40) ergs produce gradual spin-ups above the t iming noise level, while larger energy depositions produce sudden spin jumps resembling pulsar glitches. For a star with a temperature in th e observed range of the Vela pulsar, an energy deposition of similar t o 10(42) ergs produces a large spin-up taking place over minutes, simi lar to the Vela ''Christmas'' glitch. Comparable energy deposition in a younger and hotter ''Crab-like'' star produces a smaller spin-up tak ing place over similar to 1(d), similar to that seen during the partia lly time-resolved Crab glitch of 1989.