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

3D Velocities of Local Group dwarf galaxies combining HST and Gaia

22 Mar 2023, 10:25
Haus H, Telegrafenberg

Haus H, Telegrafenberg

Potsdam, Germany
Poster SESSION 3 : Dwarf galaxies: dwarf spheroidal, ultra-faint dwarfs, dwarf irregulars SESSION 3 : Dwarf galaxies: dwarf spheroidal, ultra-faint dwarfs, dwarf irregulars


Paul Bennet (Space Telescope Science Institute)


Gaia has revolutionized our understanding of the Milky Way (MW) and its satellite system. However, the proper motions (PMs) of dwarf galaxies outside the MW system remain out of reach by Gaia and will remain so even with future data releases. This is problematic, as it means that our understanding of systems outside the MW will be limited and we may be basing much of our cosmological modeling on the MW alone, which may be atypical. This limitation can be overcome through the use data from the Hubble Space Telescope, either obtained at two different epochs, or at one past epoch and combined with more recent Gaia positions. I will present new PMs obtained in this manner for a sample of distant dwarf galaxies in the Local Group (LG), expanding the number of systems for which we have full position-velocity information. These can be used to calculate the implied orbits. I will discuss how this information allows new science with the LG dwarfs and their hosts, linking the star formation and orbital histories of dwarfs to determine when specific dwarfs quenched and whether they are first-infall or ‘backsplash’ galaxies and how we can use this to determine host properties such as halo mass and the extent of the hot gas halo.

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

Primary author

Paul Bennet (Space Telescope Science Institute)


Dr Andres del Pino (Centro de Estudios de Física del Cosmos de Aragón) Ekta Patel (UC Berkeley) Dr Roeland van der Marel (STScI) Tony Sohn (Space Telescope Science Institute)

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