Column density of the Be star accretion disk from the SPH simulation at time t = 30 P_b. The Be star is represented by the large white circle, while the small white circle represents the companion neutron star. The size of the circle denotes the accretion radius of the sink. The left panel shows the view looking down on the x–y binary orbital plane, while the middle and right panels show the view in the x–z and y–z planes, respectively. The disk is initially circular and coplanar to the binary orbital plane. The Be star disk becomes eccentric due to the presence of the 3:1 resonance within the disk.