Estimation of the Star Formation Rate of Galaxies with Radio Continuum Obtained with Murchison Widefield Array

TL;DR

This study demonstrates that low-frequency radio continuum emission correlates well with infrared emission in star-forming galaxies, validating its use as a dust-extinction-free indicator of star formation rate across a wide frequency range.

Contribution

It shows that a single power-law describes the far-infrared-to-radio correlation up to 1.5 GHz, supporting radio continuum as a reliable SFR estimator at various redshifts.

Findings

Radio continuum correlates with IR emission in star-forming galaxies.

A single power-law fits the FIR-radio correlation across GLEAM frequencies.

Radio emission can serve as a dust-free SFR indicator from local to high redshifts.

Abstract

We investigate the correlation between the integrated low-frequency and infrared (IR) emissions of star-forming galaxies extracted from the {\sl Herschel} Reference Survey. By taking advantage of the GaLactic Extragalactic All-sky MWA (GLEAM) survey operated by the Murchison Widefield Array (MWA) we examine how this correlation varies at a function of frequency across the 20 GLEAM narrow bands at $72\mbox{--}231\; [\mbox{MHz}]$. These examinations are important for ensuring the reliability of the radio luminosity as a SFR indicator. In this study, we focus on 18 star-forming galaxies whose radio emission is detected by the GLEAM survey. These galaxies show that a single power-law is sufficient to characterise the far-infrared-to-radio correlation across the GLEAM frequency bands and up to $1.5\; [\mbox{GHz}]$. Thus, the radio continuum in this wavelength range can serve as a good dust extinction-free SFR estimator. This is particularly important for future investigation of the cosmic SFR independently from other estimators, since the radio continuum can be detected from $z=0$ to high redshifts ($z \sim 5\mbox{--}10$) in a coherent manner.