Measurement of the evolving galaxy luminosity and mass function using clustering-based redshift inference

TL;DR

This paper introduces a clustering-based redshift inference method to measure the evolving galaxy luminosity and mass functions over a large sky area using mid-infrared photometry, enabling studies beyond traditional photo-z limitations.

Contribution

The authors develop a novel framework combining multiple reference datasets to accurately measure galaxy luminosity and mass functions up to redshift 0.6 over 7500 square degrees.

Findings

Measured galaxy luminosity and mass functions over 7500 deg² up to z<0.6.

Method effectively combines multiple reference sets for improved accuracy.

Potential for application to future large-scale surveys like Rubin Observatory and Euclid.

Abstract

We develop a framework for using clustering-based redshift inference (cluster-$z$) to measure the evolving galaxy luminosity function (GLF) and galaxy stellar mass function (GSMF) using WISE W1 ($3.4\mu m$) mid-infrared photometry and positions. We use multiple reference sets from the Galaxy And Mass Assembly (GAMA) survey, Sloan Digital Sky Survey (SDSS) and Baryon Oscillation Spectroscopic Survey (BOSS). Combining the resulting cluster-$z$s allows us to enlarge the study area, and by accounting for the specific properties of each reference set, making best use of each reference set to produce the best overall result. Thus we are able to measure the GLF and GSMF over $\sim 7500\, \mathrm{deg}^2 $ of the Northern Galactic Cap (NGC) up to $z<0.6$. Our method can easily be adapted for new studies with fainter magnitudes, which pose difficulties for the derivation of photo-$z$s. The measurement of the GSMF is currently limited by the models for k-corrections and mass-to-light ratios, rather than more complicated effects tied to the evolution of the differential galaxy bias. With better statistics in future surveys this technique is a strong candidate for studies with new emerging data from, e.g. the Vera C. Rubin Observatory, the Euclid mission or the Nancy Grace Roman Space Telescope.