During the core bounce of a supernova collapse resonant active-to-active (νa→νa), as well as active-to-sterile (νa→νs) neutrino (ν) oscillations can take place. Besides, over this phase weak magnetism increases antineutrino [Formula: see text] mean free paths, and thus its luminosity. Because the oscillation feeds mass-energy into the target ν species, the large mass-squared difference between species (νa→νs) implies a huge amount of power to be given off as gravitational waves (L GWs ~1049 erg s -1), due to anisotropic but coherent ν flow over the oscillation length. This anisotropy in the ν-flux is driven by both the universal spin-rotation and the spin-magnetic coupling. The new spacetime strain estimated this way is still several orders of magnitude larger than those from ν diffusion (convection and cooling) or quadrupole moments of the neutron star matter. This new feature turns these bursts the more promising supernova gravitational-wave signal that may be detected by observatories as LIGO, VIRGO, etc., for distances far out to the VIRGO cluster of galaxies.
Structure and kinematics of the Virgo cluster of galaxies
