Numerical-relativity simulations of long-lived remnants of binary neutron star mergers

Understand

We analyze the properties of the gravitational wave signal emitted after the merger of a binary neutron star system when the remnant survives for more than a 80 ms (and up to 140ms).

• We employ four different piecewise polytropic equations of state supplemented by an ideal fluid thermal component.
• We find that the post-merger phase can be subdivided into three phases: an early post-merger phase (where the quadrupole mode and a few subdominant features are active), the intermediate post-merger phase (where only the quadrupole mode is active) and the late post-merger phase (where convective instabilities trigger inertial modes).
• The inertial modes have frequencies somewhat smaller than the quadrupole modes.