The Stellar Mass in and around Isolated Central Galaxies: Connections to the Total Mass Distribution through Galaxy–Galaxy Lensing in the Hyper Suprime-Cam Survey

Abstract

Abstract Using photometrically selected galaxies from the Hyper Suprime-Cam (HSC) survey, we measure the stellar-mass density profiles for satellite galaxies around isolated central galaxies (ICGs) from SDSS/DR7 at z ∼ 0.1. By stacking HSC images, we also measure the projected stellar-mass density profiles for ICGs and their stellar halos. The total mass distributions are further measured from HSC weak-lensing signals. ICGs dominate within ∼0.15 times the halo virial radius (0.15 R 200). The stellar mass versus total mass fractions drop with the increase in projected distance up to ∼0.15 R 200, beyond which they are less than 1% while staying almost constant. The integrated stellar mass in satellites is proportional to the virial mass of the host halo, M 200, for ICGs more massive than 1010.5 M ⊙, i.e., M *,sat ∝ M 200, whereas the relation between the stellar mass of ICGs + stellar halos and M 200 is close to M * , ICG + diffuse ∝ M 200 1 / 2 . Below 1010.5 M ⊙, the change in M 200 is much slower with the decrease in M *,ICG+diffuse. At fixed stellar mass, red ICGs are hosted by more massive dark matter halos and have more satellites. At M 200 ∼ 1012.7 M ⊙, both M *,sat and the fraction of stellar mass in satellites versus total stellar mass, f sat, tend to be marginally higher around blue ICGs. f sat increases with the increase in both M *,ICG+diffuse and M 200, and scales more linearly with M 200. We provide best-fitting relations to M 200 versus M *,ICG+diffuse, M *,sat or M *,ICG+diffuse + M *,sat, and to f sat versus M 200 or M *,ICG+diffuse, for red and blue ICGs separately.