A schematic view of the history of the accretion disk and the flyby object

The three plots starting from the bottom left are snapshots from the numerical simulation, capturing the system right at the flyby event, 4,000 years after, and 8,000 years after, respectively. The top right image is from the ALMA observations, showing the disk with spirals and the two objects around it, corresponding to the system at 12,000 years after the flyby event. Image credit: Lu et al.