Joint Astrophysical Colloquium
A Gaia-aided view of the properties of Local Group dwarf galaxies
Giuseppina Battaglia (IAC)
Thursday 21/04/2022 @ 11:30, Sala IV piano Battiferro + remote
The Local Group hosts about 100 dwarf galaxies, i.e. galaxies with stellar masses at least one order of magnitude lower than that of the Milky Way. As the smallest galaxies and the most dark matter dominated ones that we can observe, these nearby dwarf galaxies are widely considered as precious systems to shed light on the processes that drive galaxy formation and evolution at small halo masses. Nonetheless, the majority of them are found in the surrounding of a much larger system, i.e. the Milky Way or M31; this makes the knowledge of the orbits around the host a crucial piece of information for investigating the role of environment in shaping the dwarf galaxies' observed properties. In addition, this type of information can also be used to improve our understanding of the Milky Way, e.g. its gravitational potential. In this talk I will present the results of recent works, in which the exquisite astrometric data from the ESA Gaia mission are used to provide the missing information on the systemic proper motions for the majority of Local Group dwarf galaxies, out to 1.4Mpc. I will then discuss the implications of the orbital properties determined for the galaxies within 500 kpc from the Milky Way on dwarf galaxies's group infall onto the Milky Way, on the dwarf's star formation histories and internal dynamics, as well as on properties of the Milky Way itself.