- Modern astronomy reveals an abundance of neutron stars and black holes in the Milky Way and beyond. Further understanding obtains from multi-messenger observations of MeV-neutrinos from the core-collapse supernova SN1987A and gravitational radiation from the double neutron star merger GW170817. A key open question is the lifetime of the hyper-massive neutron star (HNS) in the immediate aftermath of the latter. To search for the unknown, we developed spectrograms of broadband extended gravitational-wave emission produced by GPU-accelerated butterfly filtering. We serendipitously discovered a descending chirp, starting ts = 0.67s post-merger emitting (3.5±1)% M⦿c2 over ~5s contemporaneous with GRB17017A. Evidence is based on background and foreground analysis and signal injection experiments. While this emission exceeds the maximal spin-energy of a HNS, it agrees with quadrupole radiation by a non-axisymmetric thick disk or torus sustained over the lifetime of rapid spin of a black hole following gravitational collapse prior to ts. I will present this new finding on calorimetric evidence of rotating black holes, its astrophysical implications and possible counterparts in core-collapse supernovae in the Local Universe, the most energetic of which are known as progenitors of long GRBs.
- van Putten, Della Valle & Levinson, 2019, ApJ, 876, L2
DocDB Version 8.7.10, contact
Document Database Administrators