Constraining the Stellar-to-Halo Mass Relation with Galaxy Clustering and Weak Lensing from DES Year 3 Data

We develop a framework to study the relation between the stellar mass of a galaxy and the total mass of its host dark matter halo using galaxy clustering and galaxy-galaxy lensing measurements. We model a wide range of scales, roughly from to , using a theoretical framework based on the Halo Occupation Distribution and data from Year 3 of the Dark Energy Survey (DES) dataset. The new advances of this work include: 1) the generation and validation of a new stellar mass-selected galaxy sample in the range of log M ⋆ / M ⊙ ∼ 9.6 to ∼ 11.5 ; 2) the joint-modeling framework of galaxy clustering and galaxy-galaxy lensing that is able to describe our stellar mass-selected sample deep into the 1-halo regime; and 3) stellar-to-halo mass relation (SHMR) constraints from this dataset. In general, our SHMR constraints agree well with existing literature with various weak lensing measurements. We constrain the free parameters in the SHMR functional form log M ⋆ ( M h ) = log ( ϵ M 1 ) + f [ log ( M h / M 1 ) ] − f ( 0 ) , with f ( x ) ≡ − log ( 10 α x + 1 ) + δ [ log ( 1 + exp ( x ) ) ] γ / [ 1 + exp ( 10 − x ) ] , to be log M 1 = 11.506 − 0.404 + 0.325 , log ϵ = − 1.632 − 0.181 + 0.306 , α