A LOFAR-IRAS cross-match study: The far-infrared radio correlation and the 150 MHz luminosity as a star-formation rate tracer

Abstract

Aims. We aim to study the far-infrared radio correlation (FIRC) at 150 MHz in the local Universe (at a median redshift z ∼0.05) and improve the use of the rest-frame 150 MHz luminosity, L 150, as a star-formation rate (SFR) tracer, which is unaffected by dust extinction. Methods. We cross-match the 60 μm selected Revised IRAS Faint Source Survey Redshift (RIFSCz) catalogue and the 150 MHz selected LOFAR value-added source catalogue in the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) Spring Field. We estimate L 150 for the cross-matched sources and compare it with the total infrared (IR) luminosity, L IR, and various SFR tracers. Results. We find a tight linear correlation between log L 150 and log L IR for star-forming galaxies, with a slope of 1.37. The median qIR value (defined as the logarithm of the L IR to L 150 ratio) and its rms scatter of our main sample are 2.14 and 0.34, respectively. We also find that log L 150 correlates tightly with the logarithm of SFR derived from three different tracers, i.e., SFR Hα based on the Hα line luminosity, SFR 60 based on the rest-frame 60 μm luminosity and SFR IR based on L IR, with a scatter of 0.3 dex. Our best-fit relations between L 150 and these SFR tracers are, log L 150 (L ) = 1.35(±0.06) × log SFR Hα (M yr-1) + 3.20(±0.06), log L 150 (L ) = 1.31(±0.05) × log SFR 60 (M yr-1) + 3.14(±0.06), and log L 150 (L ) = 1.37 (±0.05) × log SFR IR (M yr-1) + 3.09(±0.05), which show excellent agreement with each other.