2007ApJ...667L..45M

I consider in light of MOND the three debris galaxies discussed recently by Bournaud et al. These exhibit mass discrepancies of a factor of a few within several scale lengths of the visible galaxy, which, arguably, is contrary to the expectations from the cold dark matter paradigm. I show here that the rotational velocities predicted by MOND agree well with the observed velocities for each of the three galaxies, with only the observed baryonic matter as the source of gravity. There is thus no need to invoke a new form of baryonic, yet-undetected matter that dominates the disk of spiral galaxies, as advocated by Bournaud et al. I argue on other grounds that the presence of such ubiquitous disk dark matter, in addition to cold dark matter, is not likely.