Properties , structure , and thermal evolution of neutron stars are determined by the equation of state of stellar matter .
Recent data on isospin-diffusion and isoscaling in heavy-ion collisions at intermediate energies as well as the size of neutron skin in ^ { 208 } Pb have constrained considerably the density dependence of the nuclear symmetry energy and , in turn , the equation of state of neutron-rich nucleonic matter .
These constraints could provide useful information about the global properties of rapidly rotating neutron stars .
Models of rapidly rotating neutron stars are constructed applying several nucleonic equations of state .
Particular emphasis is placed on configurations rotating rigidly at 716 and 1122 Hz .
The range of allowed hydrostatic equilibrium solutions is determined and tested for stability .
The effect of rotation on the internal composition and thermal properties of neutron stars is also examined .
At a given rotational frequency , each equation of state yields a range of possible neutron stars configurations restricted by the Keplerian ( mass-shedding ) limit , corresponding to the maximal circumferential radius , and the limit due to the onset of instabilities with respect to axial-symmetric perturbations , corresponding to the minimal equatorial radius of a stable neutron star model .
We show that the mass of a neutron star rotating uniformly at 1122 Hz is between 1.7 and 2.1 M _ { \sun } .
Central stellar density and proton fraction decrease with increasing rotational frequency with respect to static models , and depending on the exact stellar mass and angular velocity , can drop below the Direct Urca threshold thus closing the fast cooling channel .