The Gaia inertial reference frame and the tilting of the Milky Way disk

  title={The Gaia inertial reference frame and the tilting of the Milky Way disk},
  author={Michael A. C. Perryman and David N. Spergel and Lennart Lindegren},
  journal={The Astrophysical Journal},
While the precise relationship between the Milky Way disk and the symmetry planes of the dark matter halo remains somewhat uncertain, a time-varying disk orientation with respect to an inertial reference frame seems probable. Hierarchical structure formation models predict that the dark matter halo is triaxial and tumbles with a characteristic rate of similar to 2 rad H-0(-1) (similar to 30 mu as yr(-1)). These models also predict a time-dependent accretion of gas, such that the angular… 

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