Stars A and C obey a n = 1 polytropic equation of state, P=KρΓ0, at t = 0. They are evolved according to the adiabatic evolution law, P=(Γ-1)ρ0&epsilon, where P is the pressure, K the polytropic constant, &epsilon is the internal specific energy, and ρ0 the rest-mass density. We chose Γ = 2 to mimick stiff nuclear matter. Both stars are irrotational (nonspinning) and are in a quasiequilibrium circular orbit.
We consider two differing BHNS mass ratios: case A1-farbc, with mass ratio MBH:MNS = 3:1 and case C, with a mass ratio MBH:MNS = 1:1. The initial compaction of the neutron star for both cases is MNS/RNS = 0.145.