RAPIDLY ROTATING NEUTRON-STARS IN GENERAL-RELATIVITY - REALISTIC EQUATIONS OF STATE

We construct equilibrium sequences of rotating neutron stars in genera l relativity. We compare results for 14 nuclear matter equations of st ate. We determine a number of important physical parameters for such s tars, including the maximum mass and maximum spin rate. The stability of the configurations to quasi-radial perturbations is assessed. We em ploy a numerical scheme particularly well suited to handle rapid rotat ion and large departures from spherical symmetry. We provide an extens ive tabulation of models for future reference. Two classes of evolutio nary sequences of fixed baryon rest mass and entropy are explored: nor mal sequences, which behave very much like Newtonian evolutionary sequ ences, and supramassive sequences, which exist for neutron stars solel y because of general relativistic effects. Adiabatic dissipation of en ergy and angular momentum causes a star to evolve in a quasi-stationar y fashion along an evolutionary sequence. Supramassive sequences have masses exceeding the maximum mass of a nonrotating neutron star. A sup ramassive star evolves toward eventual catastrophic collapse to a blac k hole. Prior to collapse, the star actually spins up as it loses angu lar momentum, an effect that may provide an observable precursor to gr avitational collapse to a black hole.