Precession of the Eccentric Disc

Fig. 5(a) shows the evolution of the angle $\phi$ between the eccentric vector of the disc and that of the binary orbit. The precession frequency $d\phi/dt$ averaged between $nP_{\rm orb}$ and $(n+1)P_{\rm orb}$ $(n = 0, 1, 2, \ldots)$ is given in Fig. 5(b). The solid line is for $d\phi /dt>0$ (prgrade precession), while the dashed line is for $d\phi /dt<0$ (retrograde precession).

Figure 5: The precession of the eccentric disc: (a) the angle $\phi$ between the eccentric vector of the disc and that of the binary orbit and (b) the precession frequency averaged over each time bin. The solid line is for $d\phi /dt>0$, while the dashed line is for $d\phi /dt<0$.