Observational evidence of gravitational collapse of a hyper-massive neutron star post-merger to GW170817
| Main Author: | van Putten, Maurice H.P.M. |
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| Format: | info Proceeding eJournal |
| Terbitan: |
, 2019
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/3528005 |
Daftar Isi:
- Nico van Kampen Colloquium, ITP, Utrecht (Oct 23 2019). 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 < 1s 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.