MOND simulation suggests the origin of some peculiarities in the Local Group

Understand

(abridged) The Milky Way (MW) and Andromeda (M31) galaxies possess rotating planes of satellites.

• Their formation has not been explained satisfactorily yet.
• It was suggested that the MW and M31 satellites are ancient tidal dwarf galaxies, which could explain their configuration.
• This suggestion gained support by an analytic backward calculation of the relative MW-M31 orbit in the MOND modified dynamics paradigm by Zhao et al.