Abstract:
The frequency shifts and line broadening of radiation from the surface of rapidly rotating neutron stars are calculated using a rotationally perturbed interior spherical metric and a representative choice of the equation of state for neutron star matter. The effect of rotation on the surface redshift and Doppler broadening are found to be substantial for rotation close to the secular instability limit, relevant for fast pulsars. If gamma-ray line emission originates from the surface of such pulsars, the results presented here can be used to constrain the validity of the equation of state of matter at high densities.
