Density Contour in the Equatorial Plane
Equal mass irrotational binary
Polytropic index n=1
Compactness of neutron star : Gm/Rc^2 = 0.16
Initial orbital separation : r ~ 8.6 GM/c^2
White circle in the last stage : Apparent horizon
(633, 633, 317) grid point simulation; (121, 121) region is shown