Figure 6

Figure 6: Dimensionless binding energy E ∕M b 0 vs. dimensionless orbital frequency M Ω 0, where M0 is the total ADM (Arnowitt–Deser–Misner) mass of the two components at infinite separation, for two QE NS-NS sequences that assume a piecewise polytropic NS EOS. The equal-mass case assumes MNS = 1.35M ⊙ for both NSs, while the unequal-mass case assumes M1 = 1.15M ⊙ and M2 = 1.55M ⊙. The thick curves are the numerical results, while the thin curves show the results from the 3PN approximation. The lack of any minimum suggests that instability for these configurations occurs at the onset of mass shedding, and not through a secular orbital instability. Image reproduced by permission from Figure 16 of [305], copyright by AAS.