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The intermediate age population of the Galactic halo

  • Jeremy MouldEmail author
Original Article
  • 45 Downloads

Abstract

We have learned recently that the inner halo of the Milky Way contains a kinematically coherent component (Gaia-Enceladus) from a significant merger 10 Gyrs ago. By contrast the inner (defined to exclude the Magellanic Stream) halo contains no similar intruder stellar population of billion year age. The tracer we use to set the corresponding upper limit is Gaia asymptotic giant branch stars, rather than Gaia kinematics. The primary sample is drawn from Gaia DR2 with SkyMapper photometry. This is supplemented with PanSTARRS and 2MASS photometry. As the Gaia mission proceeds, a star formation history in the galactic halo should emerge.

Keywords

Parallax Stars—red giants Galaxies: halos 

Notes

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Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.Centre for Astrophysics and SupercomputingSwinburne University of TechnologyMelbourneAustralia

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