Subsolar strange star mergers produce a lower post-merger-to-cutoff GW frequency ratio than neutron star mergers, cleanly separating the two classes across equations of state and mass ratios.
Implementation of advanced Riemann solvers in a neutrino-radiation magnetohydrodynamics code in numerical relativity and its application to a binary neutron star merger
3 Pith papers cite this work. Polarity classification is still indexing.
abstract
We implement advanced Riemann solvers HLLC and HLLD \cite{Mignone:2005ft,MUB:2009} together with an advanced constrained transport scheme \cite{Gardiner:2007nc} in a numerical-relativity neutrino-radiation magnetohydrodynamics code. We validate our implementation by performing a series of one- and multi-dimensional test problems for relativistic hydrodynamics and magnetohydrodynamics in both Minkowski spacetime and a static black hole spacetime. We find that the numerical solutions with the advanced Riemann solvers are more accurate than those with the HLLE solver \cite{DelZanna:2002rv}, which was originally implemented in our code. As an application to numerical relativity, we simulate an asymmetric binary neutron star merger leading to a short-lived massive neutron star both with and without magnetic fields. We find that the lifetime of the rotating massive neutron star formed after the merger and also the amount of the tidally-driven dynamical ejecta are overestimated when we employ the diffusive HLLE solver. We also find that the magnetorotational instability is less resolved when we employ the HLLE solver because of the solver's large numerical diffusivity. This causes a spurious enhancement both of magnetic winding resulting from large scale poloidal magnetic fields, and also of the energy of the outflow induced by magnetic pressure.
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astro-ph.HE 3years
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High-resolution GR neutrino-radiation MHD simulation of 1.35-1.35 Msun BNS merger shows KHI-driven B-field amplification to magnetar levels (~10^50 erg, factor >=316) in 3 ms post-merger.
A grid-based multi-grid Poisson solver is implemented in numerical relativity, tested on puncture black holes and neutron stars, and used in a neutrino-radiation hydrodynamics simulation of 9 solar mass star collapse up to core bounce with high conservation accuracy.
citing papers explorer
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Subsolar-mass binary mergers of strange stars and neutron stars: gravitational waves and ejecta
Subsolar strange star mergers produce a lower post-merger-to-cutoff GW frequency ratio than neutron star mergers, cleanly separating the two classes across equations of state and mass ratios.
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A magnetar formation in binary neutron star merger
High-resolution GR neutrino-radiation MHD simulation of 1.35-1.35 Msun BNS merger shows KHI-driven B-field amplification to magnetar levels (~10^50 erg, factor >=316) in 3 ms post-merger.
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Implementation of multi-grid Poisson solver in numerical relativity and its application to gravitational collapse of massive star
A grid-based multi-grid Poisson solver is implemented in numerical relativity, tested on puncture black holes and neutron stars, and used in a neutrino-radiation hydrodynamics simulation of 9 solar mass star collapse up to core bounce with high conservation accuracy.