Local Group Gaia eDR3 systemic motions

The outputs of the analysis for each galaxy, including probabilities of membership, will be made publicly available. The analysis is augmented by a determination of the orbital properties of galaxies within 500kpc.

We adopt a flexible Bayesian methodology presented in the literature, which takes into account the location of the stars on the sky, on the colour-magnitude diagram, and on the proper motion plane. We applied some modifications, in particular to the way the colour-magnitude diagram and spectroscopic information are factored in, for example, by including stars in several evolution phases. The bulk motions were integrated in three gravitational potentials: two where the Milky Way was treated in isolation and has a mass 0.9 & 1.6x10^12^M_{sun}_, and a time-varying potential, which includes the infall of a massive Large Magellanic Cloud (LMC).