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

¹ SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD Groningen, The Netherlands
e-mail: l.wang@sron.nl
² Kapteyn Astronomical Institute, University of Groningen, Postbus 800, 9700 AV Groningen, The Netherlands
³ Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
⁴ Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, UK
⁵ SUPA, Institute for Astronomy, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
⁶ INAF – Istituto di Radioastronomia, and Italian ALMA Regional Centre, Via Gobetti 101, 40129 Bologna, Italy
⁷ INAF – Osservatorio Astronomico di Padova, Vicolo Osservatorio 5, 35122 Padova, Italy
⁸ Astronomical Observatory of the Jagiellonian University, ul. Orla 171, 30-244 Kraków, Poland
⁹ Department of Physics and Astronomy, University of Hawaii, 2505 Correa Road, Honolulu, HI 96822, USA
¹⁰ Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA
¹¹ CSIRO Astronomy and Space Science, PO Box 1130 Bentley, Perth, WA 6102, Australia
¹² Centre for Astrophysics Research, School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK
¹³ Astronomy Centre, Dept. of Physics & Astronomy, University of Sussex, Brighton BN1 9QH, UK

Received: 17 May 2019
Accepted: 10 September 2019

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, L₁₅₀, 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 L₁₅₀ 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 L₁₅₀ 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 L₁₅₀ ratio) and its rms scatter of our main sample are 2.14 and 0.34, respectively. We also find that log L₁₅₀ correlates tightly with the logarithm of SFR derived from three different tracers, i.e., SFR_Hα based on the Hα line luminosity, SFR₆₀ 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 L₁₅₀ and these SFR tracers are, log L₁₅₀ (L_⊙) = 1.35(±0.06) × log SFR_Hα (M_⊙ yr⁻¹) + 3.20(±0.06), log L₁₅₀ (L_⊙) = 1.31(±0.05) × log SFR₆₀ (M_⊙ yr⁻¹) + 3.14(±0.06), and log L₁₅₀ (L_⊙) = 1.37 (±0.05) × log SFR_IR (M_⊙ yr⁻¹) + 3.09(±0.05), which show excellent agreement with each other.