The Dependence of Galaxy Clustering on Stellar-mass Assembly History for LRGs

We analyze the spectra of 300,000 luminous red galaxies (LRGs) with stellar masses {M}_* ≳ {10}¹¹ {M}_⊙ from the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). By studying their star formation histories, we find two main evolutionary paths converging into the same quiescent galaxy population at z∼ 0.55. Fast-growing LRGs assemble 80% of their stellar mass very early on (z∼ 5), whereas slow-growing LRGs reach the same evolutionary state at z∼ 1.5. Further investigation reveals that their clustering properties on scales of ∼1-30 Mpc are, at a high level of significance, also different. Fast-growing LRGs are found to be more strongly clustered and reside in overall denser large-scale structure environments than slow-growing systems, for a given stellar-mass threshold. Our results show a dependence of clustering on a property that is directly related to the evolution of galaxies, I.e., the stellar-mass assembly history, for a homogeneous population of similar mass and color. In a forthcoming work, we will address the halo connection in the context of galaxy assembly bias.