Legacy Survey BHB stars

The measured average radial density profile follows a double power law in the range 5<r_gc_/kpc<120, with a density break at r_gc_=~20kpc. This description, however, falls short, depending on the chosen line-of-sight, with some regions showing no signature of a break in the profile and a wide range of density slopes, e.g. outer slope -5.5<~{alpha}_out_<~-4, pointing towards a highly anisotropic stellar halo.

This explains in part the wide range of density profiles reported in the literature owing to different tracers and sky coverage. Using our detailed 3-D stellar halo density map, we quantify the shape of the Pisces overdensity associated with the transient wake response of the Galaxy's (dark) halo to the Large Magellanic Cloud (LMC). Measured in the LMC's coordinate system, Pisces stands above the background, is 60 degrees long and 25 degrees wide and aligned with the LMC's orbit.