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

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 R₂₀₀). The stellar mass versus total mass fractions drop with the increase in projected distance up to ~0.15 R₂₀₀, 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, M₂₀₀, for ICGs more massive than 10^10.5M_⊙, i.e., M_*,sat ∝ M₂₀₀, whereas the relation between the stellar mass of ICGs + stellar halos and M₂₀₀ is close to ${M}_{* ,\mathrm{ICG}+\mathrm{diffuse}}\propto {M}_{200}^{1/2}$ . Below 10^10.5M_⊙, the change in M₂₀₀ 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 M₂₀₀ ~ 10^12.7M_⊙, 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 M₂₀₀, and scales more linearly with M₂₀₀. We provide best-fitting relations to M₂₀₀ versus M_{*,ICG+diffuse}, M_*,sat or M_{*,ICG+diffuse} + M_*,sat, and to f_sat versus M₂₀₀ or M_{*,ICG+diffuse}, for red and blue ICGs separately.