High resolution numerical relativity simulations for the merger of binary magnetized neutron stars

By Kentaro Kiuchi, K. Kyutoku, Y. Sekiguchi, M. Shibata, T. Wada. 2014

133 citations recorded by the source corpus.

We perform high-resolution magnetohydrodynamics simulations of binary neutron star mergers in numerical relativity on the Japanese supercomputer K. The neutron stars and merger remnants are covered by a grid spacing of 70 m, which yields the highest-resolution results among those derived so far. By an in-depth resolution study, we clarify several amplification mechanisms of magnetic fields during the binary neutron star merger for the first time. First, the Kelvin-Helmholtz instability developed in the shear layer at the onset of the merger significantly amplifies the magnetic fields. A hypermassive neutron star (HMNS) formed after the merger is then subject to the nonaxisymmetric magnetorotational instability, which amplifies the magnetic field in the HMNS. These two amplification mechanisms cannot be found with insufficient-resolution runs. We also show that the HMNS eventually collapses to a black hole surrounded by an accretion torus which is strongly magnetized at birth.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/98b8bdba10a4728c27a8e271ddbf90a2150a8bed

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In Astronomy and Astrophysics

Citations in the corpus

Long-term GRMHD simulations of neutron star merger accretion discs: implications for electromagnetic counterparts (2018, background): “A larger body of literature exists on magnetized merger simulations (e.g., Rezzolla et al. 2011; Kiuchi et al. 2014; Paschalidis et al. 2015; Kiuchi et al. 2015; Ruiz et al. 2016).”
Binary Neutron Star Mergers: Mass Ejection, Electromagnetic Counterparts, and Nucleosynthesis (2018, background): “Moreover, we cannot self-consistently treat the transport of angular momentum in the merger remnant, which is primarily due to magnetic stresses (Duez et al. 2006; Kiuchi et al. 2014, 2018; Guilet et al. 2017).”
Kilonova from post-merger ejecta as an optical and near-infrared counterpart of GW170817 (2017, background): “…the final element abundances), and its spatial distribution, are still unclear due to difficulties in resolving the turbulence and sophisticated treatment of neutrinos in numerical simulations (see e.g., Price & Rosswog 2006; Kiuchi et al. 2014; Giacomazzo et al. 2015; Siegel & Metzger 2017).”
Constraining the Maximum Mass of Neutron Stars from Multi-messenger Observations of GW170817 (2017, background): “MHD BNS merger simulations find that ultra-strong magnetic fields & 1015 − 1016 G are generated in the merger remnant (e.g. Kiuchi et al. 2014).”
RADIOACTIVITY AND THERMALIZATION IN THE EJECTA OF COMPACT OBJECT MERGERS AND THEIR IMPACT ON KILONOVA LIGHT CURVES (2016, background): “Kilonova ejecta contain a residual magnetic field, either inherited directly from the parent NSs, or seeded by amplified fields produced by turbulence during the merger or in the resultant accretion disk (Kiuchi et al. 2014, 2015).”
A burst in a wind bubble and the impact on baryonic ejecta: high-energy gamma-ray flashes and afterglows from fast radio bursts and pulsar-driven supernova remnants (2016, methodology): “The total ejected mass is rather uncertain and depends on the binary parameters; for example, Mext ∼ 10−5 − 10−2 M⊙ for a NS-NS binary based on numerical simulations (see, e.g., Kiuchi et al. 2014; Sekiguchi et al. 2015).”
Mass Ejection from the Remnant of a Binary Neutron Star Merger: Viscous-radiation Hydrodynamics Study (2017, background): “…note that the variation of the quasi-equilibrium configuration occurs only if the viscous effect is enhanced after the dynamical phase of the merger ends, e.g., by MHD turbulence induced by the significantly amplified magnetic fields at the onset of the merger(Kiuchi et al. 2014, 2015b, 2017).”