DESI Emission-line Galaxies: Clustering Dependence on Stellar Mass and [OII] Luminosity

TL;DR

This study analyzes how the clustering of DESI emission-line galaxies depends on stellar mass and [OII] luminosity, revealing that most are central galaxies in narrow halo mass ranges with weak clustering dependence on stellar mass.

Contribution

It models the clustering dependence on stellar mass and [OII] luminosity simultaneously, providing insights into galaxy-halo connections at redshifts 0.8 to 1.6.

Findings

Most ELGs are central galaxies in halos of median mass ~10^{12.2-12.4} h^{-1} M_sun.

Weak clustering dependence on stellar mass likely due to measurement uncertainties.

A trend between galaxy bias and [OII] luminosity exists at high redshift, absent at lower redshifts.

Abstract

We measure the projected two-point correlation functions of emission-line galaxies (ELGs) from the Dark Energy Spectroscopic Instrument (DESI) One-Percent Survey and model their dependence on stellar mass and [OII] luminosity. We select $\sim$180,000 ELGs with redshifts of $0.8 < z < 1.6$ and define 27 samples according to cuts in redshift and both galaxy properties. Following a framework that describes the conditional [OII] luminosity-stellar mass distribution as a function of halo mass, we simultaneously model the clustering measurements of all samples at fixed redshift. Based on the modeling result, most ELGs in our samples are classified as central galaxies, residing in halos of a narrow mass range with a typical median of $\sim$10$^{12.2-12.4}$ $h^{-1} M_\odot$. We observe a weak dependence of clustering amplitude on stellar mass, which is reflected in the model constraints and is likely a consequence of the 0.5 dex measurement uncertainty in the stellar mass estimates. The model shows a trend between galaxy bias and [OII] luminosity at high redshift ($1.2 < z < 1.6$) that is otherwise absent at lower redshifts.