The clustering of luminous red galaxies at z $\sim$ 0.7 from eBOSS and BOSS data

TL;DR

This paper analyzes the clustering of luminous red galaxies at redshift around 0.7 using eBOSS and BOSS data, providing insights into galaxy bias, halo occupation, and evolution over 7 billion years.

Contribution

First measurement of small and intermediate scale clustering of eBOSS LRGs at z~0.7, interpreting results with Halo Occupation Distribution and comparing with previous surveys.

Findings

Bias of eBOSS LRGs is 2.30 ± 0.03

Satellite fraction is 13 ± 3%

Mean halo mass is 2.5×10^{13} h^{-1} M_sun

Abstract

We present the first scientific results from the luminous red galaxy sample (LRG) of the extended Baryon Oscillation Spectroscopic Survey (eBOSS). We measure the small and intermediate scale clustering from a sample of more than 61,000 galaxies in the redshift range $0.6 < z < 0.9$. We interpret these measurements in the framework of the Halo Occupation Distribution. The bias of eBOSS LRGs is $2.30 \pm 0.03$, with a satellite fraction of $13\pm3$\% and a mean halo mass of $2.5\times10^{13}h^{-1}M_{\odot}$. These results are consistent with expectations, demonstrating that eBOSS galaxies will be reliable tracers of large scale structure at $z\sim 0.7$. The eBOSS galaxy bias implies a scatter of luminosity at fixed halo mass, $\sigma_{\log L}$, of 0.19 dex. Using the clustering of massive galaxies from BOSS-CMASS, BOSS-LOWZ, and SDSS, we find that $\sigma_{\log L}=0.19$ is consistent with observations over the full redshift range that these samples cover. The addition of eBOSS to previous surveys allows investigation of the evolution of massive galaxies over the past $\sim 7$ Gyr.