Nonradial g-mode oscillations of warm neutron stars
Abstract
The adiabatic l =1 and 2 p, f, and g-mode oscillations of a numer of finite temperature neutron star models from the evolutionary sequences constructed by Richardson (1980) are compared. The general relativistic theory of spheroidal nonradial stellar oscillations is briefly reviewed, and an approximation termed the 'relativistic Cowling approximation' is introduced in analogy with its Newtonian counterpart. The resulting pulsation equations are solved in the limit of high spatial frequencies to obtain the local dispersion relation and to provide estimates of the periods of the p and g-mode oscillations. The numerical solutions of the full eigenvalue problem, still in Cowling approximation, are described. Calculations of p and f-mode periods, although the Cowling approximation is less satisfactory for these than for the g-modes, are included. The damping due to gravitational radiation for all modes, and due to neutrino emission for some of the modes, is estimated.