Architecture of the Andromeda Galaxy: a quantitative analysis of clustering in the inner stellar halo

  title={Architecture of the Andromeda Galaxy: a quantitative analysis of clustering in the inner stellar halo},
  author={Prajwal R. Kafle and S Sharma and Aaron S. G. Robotham and Geraint F. Lewis and Simon P. Driver},
  journal={Monthly Notices of the Royal Astronomical Society},
We present a quantitative measurement of the amount of clustering present in the inner $\sim30$ kpc of the stellar halo of the Andromeda galaxy (M31). For this we analyse the angular positions and radial velocities of the carefully selected Planetary Nebulae (PNe) in the M31 stellar halo. We study the cumulative distribution of pair-wise distances in angular position and line of sight velocity space, and find that the M31 stellar halo contains substantially more stars in the form of close pairs… 

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