The orbital poles of Milky Way satellite galaxies: a rotationally supported disc-of-satellites

Understand

Available proper motion measurements of Milky Way (MW) satellite galaxies are used to calculate their orbital poles and projected uncertainties.

• These are compared to a set of recent cold dark-matter (CDM) simulations, tailored specifically to solve the MW satellite problem.
• We show that the CDM satellite orbital poles are fully consistent with being drawn from a random distribution, while the MW satellite orbital poles indicate that the disc-of-satellites of the Milky Way is rotationally supported.
• Furthermore, the bootstrapping analysis of the spatial distribution of theoretical CDM satellites also shows that they are consistent with being randomly drawn.