Jet from binary neutron star merger with prompt black hole formation

Abstract

We performed the longest numerical-relativity neutrino-radiation magnetohydrodynamics simulation for a binary neutron star merger that extends to $\approx 1.5\mathrm{s}$ after the merger. We consider the binary model that undergoes the prompt collapse to a black hole after the merger with asymmetric mass 1.25$M_{\odot }$ and 1.65$M_{\odot }$ and SFHo equation of state. We find the Poynting flux-driven collimated outflow as well as the gravitational wave emission, neutrino emission, dynamical mass ejection, and post-merger mass ejection facilitated by magnetorotational instability-driven turbulent viscosity in a single self-consistent binary neutron star merger simulation. A magnetosphere dominated by the aligned global magnetic field penetrating the black hole develops along the black-hole spin axis after the turbulence in the remnant disk is enhanced. A jet with the Poynting flux with isotropic-equivalent luminosity of $\sim 10^{49}erg/s$ is launched, and the duration of the high luminosity is expected to be $O(1)\mathrm{s}$.

14 pages, 9 figures