The late capture process of the MD with its own satellite system in Aq-C ^α . The three upper rows give the components of the J _orb vector of each subsatellite, as a function of time, relative to the MD (left panels) and to the main galaxy (right panels). The evolution of the MD’s J _orb vector relative to the main galaxy is also given in the right panels (ID #836). Vertical arrows mark the capture time (T _uni ≈ 12.5 Gyr), when subsatellites become bound to the host, i.e., the beginning of the time interval along which orbital angular momentum relative to the MD is transferred to the main galaxy. The bottom panel shows an Aitoff projection of the MD’s subsatellite orbital poles, centered on the MD, along the T _uni interval between 6.0 and 11.1 Gyr, before this system is captured by the host. The corresponding J _stack axes are marked with crosses, and circles mark the co-orbitation region. Gray tracks indicate the diametrically opposite projections of each orbital pole, as we consider these as axial vectors in our method (see Section 4.1).