Hyper Suprime-Cam view of the CMASS galaxy sample. Halo mass as a function of stellar mass, size, and Sérsic index

Aims . We wish to determine the distribution of dark matter halo masses as a function of the stellar mass and the stellar mass profile for massive galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS) constant-mass (CMASS) sample.Methods . We used g r i z y photometry from the Hyper Suprime-Cam (HSC) to obtain Sersic fits and stellar masses of CMASS galaxies for which HSC weak-lensing data are available. This sample was visually selected to have spheroidal morphology. We applied a cut in stellar mass, log M * /M ⊙  >  11.0, and selected ∼10 000 objects thus. Using a Bayesian hierarchical inference method, we first investigated the distribution of Sersic index and size as a function of stellar mass. Then, making use of shear measurements from HSC, we measured the distribution of halo mass as a function of stellar mass, size, and Sersic index.Results . Our data reveal a steep stellar mass-size relation , with β R larger than unity, and a positive correlation between Sersic index and stellar mass: . The halo mass scales approximately with the 1.7 power of the stellar mass. We do not find evidence for an additional dependence of halo mass on size or Sersic index at fixed stellar mass.Conclusions . Our results disfavour galaxy evolution models that predict significant differences in the size growth efficiency of galaxies living in low- and high-mass halos.