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

Aims. We aim to study the far-infrared radio correlation (FIRC) at 150 MHz in the local Universe (at a median redshift < z > similar to 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 mu m 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 q(IR) 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., SFRH alpha based on the H alpha line luminosity, SFR60 based on the rest-frame 60 mu m luminosity and SFRIR 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-circle dot) = 1.35(+/- 0.06) x log SFRH alpha (M-circle dot yr(-1)) + 3.20(+/- 0.06), log L-150 (L-circle dot) = 1.31(+/- 0.05) x log SFR60 (M-circle dot yr(-1)) + 3.14(+/- 0.06), and log L-150 (L-circle dot) = 1.37 (+/- 0.05) x log SFRIR (M-circle dot yr(-1)) + 3.09(+/- 0.05), which show excellent agreement with each other.