Gravitational-wave signals for supernova explosions of three-dimensional progenitors

Core-collapse supernovae (SNe) are sources of gravitational waves (GWs) produced by hydrodynamical instabilities and highly time-dependent anisotropies of the neutrino radiation. In this work, we analyze both contributions to the GW signal for two state-of-the-art three-dimensional (3D) SN models computed with the rometheus-ertex neutrino hydrodynamics code. In contrast to the great majority of models analyzed for GWs so far, our core-collapse simulations were started with 12.28 M ⊙ ( 18.88 M ⊙ ) progenitors, whose final hour (7 min) of convective oxygen shell burning was computed in 3D and featured a vigorous oxygen-neon shell merger. The corresponding large-scale asymmetries in the oxygen layer are conducive to buoyancy-aided, neutrino-driven explosions. The models were continuously evolved in 3D from the precollapse evolution until 5.11 s (1.68 s) after the core bounce. The GW signals result from well-known dynamical phenomena in the SN core such as prompt postshock convection, neutrino-driven convection, the standing accretion shock instability, proto–neutron star oscillations, and anisotropic ejecta expansion. They do not exhibit any new or specific features that can be unambiguously connected to the powerful precollapse activity in the progenitors, but we identify interesting differences compared to results in the literature. We also discuss measurement prospects by interferometers, confirming that GW signals from future Galactic SNe will be detectable with existing and next-generation experiments working in the frequency range f ∼ 1 – 2000 Hz .