Radiation from collapsing relativistic stars. II - Linearized even-parity radiation

Even-parity electromagnetic and gravitational linear perturbations of Oppenheimer-Snyder collapse are studied. The even-parity electromagnetic problem is shown to be identical to the analogous odd-parity electromagnetic problem. For the gravitational case, the mathematical appearance of the even-parity problem is markedly different from that for odd-parity. Numerical results are presented, however, which show that exterior radiation fields develop quite similarly in the two problems and that previous conclusions (dominance of quasi-normal ringing, power-law tails at late times) for odd-parity radiation apply equally well to the even-parity case.