20-24 March 2023
Haus H, Telegrafenberg
Europe/Berlin timezone

Gaia EDR3 proper motions, energies, angular momenta of Milky Way dwarfs: a recent infall to the Milky Way halo

22 Mar 2023, 12:00
Haus H, Telegrafenberg

Haus H, Telegrafenberg

Potsdam, Germany
Invited topical talk SESSION 3 : Dwarf galaxies: dwarf spheroidal, ultra-faint dwarfs, dwarf irregulars SESSION 3 : Dwarf galaxies: dwarf spheroidal, ultra-faint dwarfs, dwarf irregulars


Yanbin Yang (CNRS France / Paris Observatory)


Gaia EDR3 has provided proper motions of Milky Way (MW) dwarf galaxies with an unprecedented accuracy, which allows us to investigate their orbital properties. We found that the total energy and angular momentum of MW dwarfs are much larger than that of MW K-giant stars, Sagittarius stream stars and globular clusters. It suggests that many MW dwarfs have recently infall into the Milky Way halo. We also confirmed that Milky Way dwarfs lie preferentially near their pericenters and many of them belong to a vast polar structure perpendicular to the Milky Way disk, which suggests that Milky Way dwarfs do not behave like satellite systems derived from LCDM cosmological simulations. These new results require revisiting the origin of MW dwarf galaxies, e.g., if they came recently, they were likely to have experienced gas removal due to the ram pressure induced by MW’s hot gas, and to be affected by MW tides. We will discuss the consequences of these processes on their mass estimation.

Do you plan to attend the symposium in-person or virtually? in-person

Primary author

Yanbin Yang (CNRS France / Paris Observatory)


Francois Hammer Dr Jianling Wang (NAOC China) Dr Marcel S. Pawlowski (Leibniz-Institut fur Astrophysik Potsdam (AIP)) Dr Hefan Li (NAOC China) Dr Piercarlo Bonifacio (Paris Observatory) Dr Carine Babusiaux (Université Grenoble Alpes / Paris Observatory)

Presentation Materials