Gravitational waves from supernova matter

Abstract

We have performed a set of 11 three-dimensional magnetohydrodynamical core\ncollapse supernova simulations in order to investigate the dependencies of the\ngravitational wave signal on the progenitor's initial conditions. We study the\neffects of the initial central angular velocity and different variants of\nneutrino transport. Our models are started up from a 15 solar mass progenitor\nand incorporate an effective general relativistic gravitational potential and a\nfinite temperature nuclear equation of state. Furthermore, the electron flavour\nneutrino transport is tracked by efficient algorithms for the radiative\ntransfer of massless fermions. We find that non- and slowly rotating models\nshow gravitational wave emission due to prompt- and lepton driven convection\nthat reveals details about the hydrodynamical state of the fluid inside the\nprotoneutron stars. Furthermore we show that protoneutron stars can become\ndynamically unstable to rotational instabilities at T/|W| values as low as ~2 %\nat core bounce. We point out that the inclusion of deleptonization during the\npostbounce phase is very important for the quantitative GW prediction, as it\nenhances the absolute values of the gravitational wave trains up to a factor of\nten with respect to a lepton-conserving treatment.\n