Evidence for galaxy assembly bias in BOSS CMASS redshift-space galaxy correlation function

Understand

Building accurate and flexible galaxy-halo connection models is crucial in modeling galaxy clustering on non-linear scales.

• Recent studies have found that halo concentration by itself cannot capture the full galaxy assembly bias effect and that the local environment of the halo can be an excellent indicator of galaxy assembly bias.
• In this paper, we propose an extended halo occupation distribution model (HOD) that includes both a concentration-based assembly bias term and an environment-based assembly bias term.
• We use this model to achieve a good fit (chi^2/DoF = 1.35) on the 2D redshift-space 2-point correlation function (2PCF) of the Baryon Oscillation Spectroscopic Survey (BOSS) CMASS galaxy sample.