Gravitational radiation from gamma-ray burst-supernovae as observational opportunities for LIGO and VIRGO

Gamma-ray bursts are believed to originate in the core collapse of massive stars. This produces an active MeV-nucleus containing a rapidly rotating Kerr black hole of mass M-H and angular velocity Omega(H)similar or equal to1/2M(H), surrounded by a uniformly magnetized torus of angular velocity Omega(T)=etaOmega(H) represented by two counteroriented current rings. We quantify black-hole-spin interactions with the torus and charged particles along open magnetic flux tubes subtended by the event horizon at a finite half-opening angle theta(H). A major output of E(gw)similar or equal to4x10(53)(eta/0.1)(M-H/7M(circle dot)) erg is radiated in gravitational waves of frequency f(gw)similar or equal to500(eta/0.1)(7M(circle dot)/M-H) Hz by a quadrupole mass moment in the torus when its minor-to-major radius is less than 0.3260. The durations correspond to the lifetime T-s of black hole spin, determined by a stability condition of poloidal magnetic field energy-to-kinetic energy <1/15 in the torus. Consistent with observations of GRB-SNe, we find (i) T(s)similar or equal to90 s (tens of s), (ii) aspherical SNe of kinetic energy E(SN)similar or equal to2x10(51) erg (2x10(51) erg in SN1998bw), and (iii) GRB-energies E(gamma)similar or equal to2x10(50) erg (3x10(50) erg), upon associating theta(H) with poloidal curvature of the magnetosphere. GRB-SNe occur perhaps about once a year within D=100 Mpc. Correlating LIGO-VIRGO detectors enables searches for nearby events and their spectral closure density 6x10(-9) around 250 Hz in the stochastic background radiation in gravitational waves. At current sensitivity, LIGO-Hanford may place an upper bound around 150M(circle dot) in GRB030329. Upcoming all-sky supernovae surveys may provide distances to GRB-SNe, conceivably coincident with weak wide-angle GRB emissions similar to the nearby event GRB980425/SN1998bw. Detection of E-gw thus provides a method for identifying Kerr black holes by calorimetry.