# Gravitational Waveforms

The gravitational wavetrain from a promptly collapsing NSNS merger may be separated into three qualitatively different phases: inspiral, merger, and BH ringdown. During the inspiral phase, which takes up most of the binary's lifetime, gravitational wave emission gradually reduces the binary separation. The merger phase of the gravitational wavetrain is characterized by tidal disruption of the neutron stars, followed by prompt collapse to a spinning BH. Ringdown radiation is emitted as the distorted BH settles down to Kerr-like equilibrium (Note: Only in the case of a vacuum spacetime does the spinning BH obey the exact Kerr solution. The BHs formed here are surrounded by gaseous disks with small, but nonnegligible, rest mass). The h× polarization mode of the gravitational wave is shown below.

## h× Polarization (Lower Hemisphere)

Here, we have a binary neutron star system, with the neutron stars undergoing tidal disruption. Shown below is h× in the lower hemisphere. Waveforms are plotted in the region of $r/M \geq 68$.

 Fig. 1-1: t/M = 195 Fig. 1-2: t/M = 406 Fig. 1-3: t/M = 464 Fig. 1-4: t/M = 558 Fig. 1-5: t/M = 696 Fig. 1-6: t/M = 776
Play Online