He-Feng Hsieh (NTHU); Rubén Cabezón (Universität Basel); Li-Ting Ma (NTHU); Kuo-Chuan Pan (NTHU)
We present self-consistent three-dimensional core-collapse supernova simulations of a rapid rotating 20 solar mass progenitor model with various initial rotation rates using both a smoothed particle hydrodynamics code (SPHYNX) and a grid-based Eulerian code (FLASH). We find, for the first time, that a 1.2 kilohertz gravitational wave feature is excited at ~60 ms postbounce for models with initial rotation rates higher than 2.0 rad/s, regardless of the simulation code. By analyzing the spherical harmonic modes of the proto-neutron star, we show that this kilohertz feature can be associated with m=1 modes from the proto-neutron star modulation induced by the low T/|W| instability. In addition to the bounce signal, this kilohertz signal can be another diagnosis for understanding the angular momentum distribution of the collapsing core.