Accretion-induced prompt black hole formation in asymmetric neutron star mergers, dynamical ejecta, and kilonova signals
| Autor: | Boris Daszuta, Andrea Endrizzi, Matteo Breschi, Federico Schianchi, Albino Perego, Sebastiano Bernuzzi, Néstor Ortiz, Francesco Zappa, Ignazio Bombaci, David Radice, Vsevolod Nedora, Domenico Logoteta |
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| Rok vydání: | 2020 |
| Předmět: |
Astrophysics::High Energy Astrophysical Phenomena
FOS: Physical sciences General Relativity and Quantum Cosmology (gr-qc) Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Kilonova 01 natural sciences General Relativity and Quantum Cosmology Gravitational waves 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Ejecta 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics High Energy Astrophysical Phenomena (astro-ph.HE) Physics 010308 nuclear & particles physics Gravitational wave Astronomy and Astrophysics Mass ratio Accretion (astrophysics) Black hole Neutron star Numerical relativity 13. Climate action Space and Planetary Science Astrophysics::Earth and Planetary Astrophysics Astrophysics - High Energy Astrophysical Phenomena |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 497:1488-1507 |
| ISSN: | 1365-2966 0035-8711 |
| Popis: | We present new numerical relativity results of neutron star mergers with chirp mass $1.188M_\odot$ and mass ratios $q=1.67$ and $q=1.8$ using finite-temperature equations of state (EOS), approximate neutrino transport and a subgrid model for magnetohydrodynamics-induced turbulent viscosity. The EOS are compatible with nuclear and astrophysical constraints and include a new microphysical model derived from ab-initio calculations based on the Brueckner-Hartree-Fock approach. We report for the first time evidence for accretion-induced prompt collapse in high-mass-ratio mergers, in which the tidal disruption of the companion and its accretion onto the primary star determine prompt black hole formation. As a result of the tidal disruption, an accretion disc of neutron-rich and cold matter forms with baryon masses ${\sim}0.15M_\odot$, and it is significantly heavier than the remnant discs in equal-masses prompt collapse mergers. Massive dynamical ejecta of order ${\sim}0.01M_\odot$ also originate from the tidal disruption. They are neutron rich and expand from the orbital plane with a crescent-like geometry. Consequently, bright, red and temporally extended kilonova emission is predicted from these mergers. Our results show that prompt black hole mergers can power bright electromagnetic counterparts for high-mass-ratio binaries, and that the binary mass ratio can be in principle constrained from multimessenger observations. 20 pages, 21 figures, 4 tables |
| Databáze: | OpenAIRE |
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