The Redshift Evolution of the Stellar Mass — Halo Mass Relation with Redshift from 0.03 < z < 0.6 and Beyond

The evolution in the parameters of the Stellar Mass - Halo Mass (SMHM) relation for galaxy clusters can be used to infer how brightest central galaxies grow and evolve over time. By incorporating the magnitude gap, the difference in brightness between the central and 4th brightest cluster member, we improve the precision of the inferred parameters by 30-50%. Using a combination of over 2000 clusters from SDSS and DES-Y3 with no detectable systematic differences, we study the redshift evolution uniformly over 6 billion years and detect statistically significant (> 3.5 sigma) late time evolution in the slope of the SMHM relation. Additionally, we extend this analysis out to even higher redshifts by incorporating the DES-ACT clusters to further construct an evolutionary history of central galaxy and cluster assembly.