Circularization and final spin in eccentric binary-black-hole inspirals

We present results from numerical relativity simulations of equal-mass, nonspinning binary-black-hole inspirals and mergers with initial eccentricities e≤0.8 and coordinate separations D≥12M of up to 9 orbits (18 gravitational wave cycles). We extract the mass Mf and spin af of the final black hole and find, for eccentricities e0.4, that af/Mf≈0.69 and Mf/Madm≈0.96 are independent of the initial eccentricity, suggesting that the binary has circularized by the merger time. For e0.5, the black holes plunge rather than orbit, and we obtain a maximum spin parameter af/Mf≈0.72 around $e=0.5$.