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arXiv · 1811.04934

An HSC view of the CMASS galaxy sample. Halo mass as a function of stellar mass, size and Sérsic index

Alessandro Sonnenfeld·Wenting Wang·Neta Bahcall
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Abstract

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 BOSS CMASS sample. Methods. We use grizy photometry from HSC to obtain Sérsic fits and stellar masses of CMASS galaxies for which HSC weak lensing data is available, visually selected to have spheroidal morphology. We apply a cut in stellar mass, $\log{M_*/M_\odot} > 11.0$,selecting $\sim$10, 000 objects. Using a Bayesian hierarchical inference method, we first investigate the distribution of Sérsic index and size as a function of stellar mass. Then, making use of shear measurements from HSC, we measure the distribution of halo mass as a function of stellar mass, size and Sérsic index. Results. Our data reveals a steep stellar mass-size relation $R_e \propto M_*^{β_R}$, with $β_R$ larger than unity, and a positive correlation between Sérsic index and stellar mass: $n \propto M_*^{0.46}$. 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 Sérsic 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.

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Alessandro Sonnenfeld, Wenting Wang, Neta Bahcall. 2018-11-12. An HSC view of the CMASS galaxy sample. Halo mass as a function of stellar mass, size and Sérsic index. https://doi.org/10.1051/0004-6361%2F201834260

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