The mass ejection from the merger of binary neutron stars. (arXiv:1212.0905v1 [astro-ph.HE])

The mass ejection from the merger of binary neutron stars. (arXiv:1212.0905v1 [astro-ph.HE]):
Numerical-relativity simulations for the merger of binary neutron stars are
performed for a variety of equations of state (EOSs) and for a plausible range
of the neutron-star mass, focusing primarily on the properties of the material
ejected from the system. We find that a fraction of the material is ejected as
a mildly relativistic and mildly anisotropic outflow with the typical and
maximum velocities $\sim 0.15$ -- $0.25c$ and $\sim 0.5$ -- $0.8c$ (where $c$
is the speed of light), respectively, and that the total ejected rest mass is
in a wide range $10^{-4}$ -- $10^{-2}M_{\odot}$, which depends strongly on the
EOS, the total mass, and the mass ratio. The total kinetic energy ejected is
also in a wide range between $10^{49}$ and $10^{51} {\rm ergs}$. The numerical
results suggest that for a binary of canonical total mass $2.7M_{\odot}$, the
outflow could generate an electromagnetic signal observable by the planned
telescopes through the production of heavy-element unstable nuclei via the
$r$-process or through the formation of blast waves during the interaction with
the interstellar matter, if the EOS and mass of the binary are favorable ones.