The clustering of massive galaxies at z~0.5 from the first semester of BOSS data

TL;DR

This paper analyzes the clustering of massive galaxies at z~0.5 using BOSS data, revealing their halo occupation and implications for large-scale structure studies.

Contribution

It provides a halo-occupation distribution model of massive galaxy clustering at z~0.5 based on BOSS data, highlighting galaxy-halo relationships.

Findings

Most galaxies are central in 10^{13}Msun/h halos

10% are satellites in more massive halos

Large-scale bias of about 2

Abstract

We calculate the real- and redshift-space clustering of massive galaxies at z~0.5 using the first semester of data by the Baryon Oscillation Spectroscopic Survey (BOSS). We study the correlation functions of a sample of 44,000 massive galaxies in the redshift range 0.4<z<0.7. We present a halo-occupation distribution modeling of the clustering results and discuss the implications for the manner in which massive galaxies at z~0.5 occupy dark matter halos. The majority of our galaxies are central galaxies living in halos of mass 10^{13}Msun/h, but 10% are satellites living in halos 10 times more massive. These results are broadly in agreement with earlier investigations of massive galaxies at z~0.5. The inferred large-scale bias (b~2) and relatively high number density (nbar=3e-4 h^3 Mpc^{-3}) imply that BOSS galaxies are excellent tracers of large-scale structure, suggesting BOSS will enable a wide range of investigations on the distance scale, the growth of large-scale structure, massive galaxy evolution and other topics.