The DESI One-Percent Survey: Exploring the Halo Occupation Distribution of Luminous Red Galaxies and Quasi-Stellar Objects with AbacusSummit

Kavli Affiliate: Risa H. Wechsler

| First 5 Authors: Sihan Yuan, Hanyu Zhang, Ashley J. Ross, Jamie Donald-McCann, Boryana Hadzhiyska

| Summary:

We present the first comprehensive Halo Occupation Distribution (HOD)
analysis of the DESI One-Percent survey Luminous Red Galaxy (LRG) and
Quasi-Stellar Object (QSO) samples. We constrain the HOD of each sample and
test possible HOD extensions by fitting the redshift-space galaxy 2-point
correlation functions in 0.15 < r < 32 Mpc/h in a set of fiducial redshift
bins. We use AbacusSummit cubic boxes at Planck 2018 cosmology as model
templates and forward model galaxy clustering with the AbacusHOD package. We
achieve good fits with a standard HOD model with velocity bias, and we find no
evidence for galaxy assembly bias or satellite profile modulation at the
current level of statistical uncertainty. For LRGs in 0.4 < z < 0.6, we infer a
satellite fraction of fsat = 11+-1%, a mean halo mass of log10 Mh =
13.40+0.02-0.02, and a linear bias of blin = 1.93+0.06-0.04. For LRGs in 0.6 <
z < 0.8, we find fsat = 14+-1%, log10 Mh = 13.24+0.02-0.02, and blin =
2.08+0.03-0.03. For QSOs, we infer fsat = 3+8-2%, log10 Mh = 12.65+0.09-0.04,
and blin = 2.63+0.37-0.26 in redshift range 0.8 < z < 2.1. Using these fits, we
generate a large suite of high-fidelity galaxy mocks. We also study the
redshift-evolution of the DESI LRG sample from z = 0.4 up to z = 1.1, revealing
significant and interesting trends in mean halo mass, linear bias, and
satellite fraction.

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