The MOSDEF Survey: Calibrating the relationship between H$\alpha$ star-formation rate and radio continuum luminosity at $1.4 < z < 2.6$

TL;DR

This study tests whether the local universe's relation between star-formation rate and radio luminosity holds at high redshift ($1.4<z<2.6$) and finds it remains valid, aiding high-redshift galaxy SFR measurements.

Contribution

First empirical test of the evolution of the SFR-radio luminosity relation at high redshift using dust-corrected Hα SFRs and radio data.

Findings

No evidence for evolution of the SFR-radio relation up to z~2.

Locally calibrated SFR-radio relations are valid at high redshift.

Radio luminosity can reliably indicate SFR in high-redshift galaxies.

Abstract

The observed empirical relation between the star-formation rates (SFR) of low-redshift galaxies and their radio continuum luminosity offers a potential means of measuring SFR in high redshift galaxies that is unaffected by dust obscuration. In this study, we make the first test for redshift evolution in the SFR-radio continuum relation at high redshift using dust-corrected H$\alpha$ SFR. Our sample consists of 178 galaxies from the MOSFIRE Deep Evolution Field (MOSDEF) Survey at $1.4 < z < 2.6$ with rest-frame optical spectroscopy and deep 1.5 GHz radio continuum observations from the Karl G. Jansky Very Large Array (VLA) GOODS North field. Using a stacking analysis we compare the observed radio continuum luminosities with those predicted from the dust-corrected H$\alpha$ SFR assuming a range of $z\sim0$ relations. We find no evidence for a systematic evolution with redshift, when stacking the radio continuum as a function of dust-corrected H$\alpha$ SFR and when stacking both optical spectroscopy and radio continuum as a function of stellar mass. We conclude that locally calibrated relations between SFR and radio continuum luminosity remain valid out to $z\sim 2$.