Illuminating and Tabulating the Galaxy-Halo Connection

Abstract: In the near future, a new generation of massively multiplexed spectroscopic surveys like PFS, WAVES, and MOONS will enable detailed studies of galaxy evolution across cosmic timescales and connect galaxies to dark matter halos. I have generated mock catalogs for these surveys using the CLIMBER procedure, based on the UniverseMachine model and UltraVISTA photometry. Through mock observations, I have identified that future extensions of the PFS and MOONS programs should aim to reduce cosmic variance by surveying more uncorrelated sky areas. Additionally, the development of the galtab algorithm has greatly enhanced the efficiency of HOD inference by pretabulating counts-in-cells statistics. Leveraging early data from DESI, I have explored the galaxy-halo connection by supplementing the two-point correlation function with galtab-accelerated counts-in-cylinders. Notably, my analysis reveals a positive assembly bias between the r-band luminosity and halo concentration at up to 3-sigma significance. Looking ahead, as new methodologies and datasets continue to facilitate our understanding, I anticipate that future studies and will soon shift their focus from mere detections of assembly bias to delving into its implications for galaxy formation and cosmology at greater depth.