Constraining the scatter in the galaxy-halo connection at Milky Way masses

Understand

We develop and implement two new methods for constraining the scatter in the relationship between galaxies and dark matter halos.

• These new techniques are sensitive to the scatter at low halo masses, making them complementary to previous constraints that are dependent on clustering amplitudes or rich galaxy groups, both of which are only sensitive to more massive halos.
• In both of our methods, we use a galaxy group finder to locate central galaxies in the SDSS main galaxy sample.
• Our first technique uses the small-scale cross-correlation of central galaxies with all lower mass galaxies.