Gravitational Wave Frequencies and Energies in Hypernovae

Abstract

A torus develops a state of suspended accretion against a magnetic wall around a rapidly rotating black hole formed in core-collapse hypernovae. It hereby emits about 10% of the black hole spin energy in gravitational radiation from a finite number of multipole mass moments. We quantify the relation between the frequency of quadrupole gravitational radiation and the energy output E w in torus winds by f gw ~=470Hz(E w /4×10 52 ergs) 1/ 2 (7M solar /M) 3/2, where M denotes the mass of the black hole. We propose that E w irradiates the remnant stellar envelope from within. We identify E w with energies ~10 52 ergs inferred from X-ray observations on matter injecta and the poloidal curvature in the magnetic wall with the horizon opening angle in baryon poor outflows that power true GRB energies of E γ ~=3×10 51 ergs.