Evolution of Star-forming Galaxies from z = 0.7 to 1.2 with eBOSS Emission-line Galaxies

TL;DR

This study analyzes the evolution of star-forming galaxies between redshifts 0.7 and 1.2 using eBOSS emission-line galaxies, revealing weak evolution in stellar mass relations and halo occupation, with insights into galaxy bias and satellite fractions.

Contribution

It introduces an application of the incomplete conditional stellar mass function model to constrain galaxy properties and evolution over the specified redshift range.

Findings

eBOSS ELGs only sample 1-10% of star-forming galaxies at these redshifts

Weak evolution observed in stellar-halo mass relation from z=1.2 to 0.7

Satellite fraction varies from 13% to 17%, galaxy bias increases from 1.1 to 1.4

Abstract

We study the evolution of star-forming galaxies with $10^{10} M_\odot<M_*<10^{11.6} M_\odot$ over the redshift range of 0.7<z<1.2 using the emission line galaxies (ELGs) in the extended Baryon Oscillation Spectroscopic Survey (eBOSS). By applying the incomplete conditional stellar mass function (ICSMF) model proposed in Guo et al., we simultaneously constrain the sample completeness, the stellar--halo mass relation (SHMR) and the quenched galaxy fraction. We obtain the intrinsic stellar mass functions for star-forming galaxies in the redshift bins of 0.7<z<0.8, 0.8<z<0.9, 0.9<z<1.0 and 1.0<z<1.2, as well as the stellar mass function for all galaxies in the redshift bin of 0.7<z<0.8. We find that the eBOSS ELG sample only selects about 1%-10% of the star-forming galaxy population at the different redshifts, with the lower redshift samples to be more complete. There is only weak evolution in the SHMR of the ELGs from z=1.2 to z=0.7, as well as the intrinsic galaxy stellar mass functions for lower-mass galaxies of $M_*<10^{11} M_\odot$. There is significant decrease of the stellar mass function for star-forming galaxies with redshift at the massive end. Our best-fitting models show that the central ELGs at these redshifts live in halos of mass $M\sim10^{12} M_\odot$ while the satellite ELGs occupy slightly more massive halos of $M\sim10^{12.6} M_\odot$. The average satellite fraction of the observed ELGs varies from 13% to 17%, with the galaxy bias increasing from 1.1 to 1.4 from z=0.7 to 1.2.