A MIGHTEE robust measurement of the star formation rate – radio correlation
6 affiliations
- 1University of Oxford Department of Physics, Astrophysics, , Denys Wilkinson Building, Keble Road, Oxford OX1 3RH ,
- 2University of the Western Cape Department of Physics and Astronomy, , Robert Sobukwe Road, 7535 Bellville, Cape Town ,
- 3Max Planck Institute for Extraterrestrial Physics , Giessenbachstrasse, 85741 Garching ,
- 4Excellence Cluster Universe , Boltzmannstr. 2, D-85748 Garching ,
- 5Institute for Astronomy, University of Edinburgh , Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ ,
- 6Centre for Astrophysics Research, University of Hertfordshire , Hatfield, Herts AL10 9AB ,
Abstract
Determining the relationship between star-formation rate (SFR) and the radio luminosity (L1.4) is critical if we are to trace the star-formation history of the Universe dust-agnostically using current and future radio facilities. However, until now, such work has relied on potentially biased binary classifications of sources to remove contaminating active galactic nuclei (AGN). We present a new, statistically-driven methodology for deriving the SFR – L1.4 relation, removing the need for problematic cuts. We use a Bayesian hierarchical mixture model fit to the radio-detected sources in the deep MIGHTEE COSMOS DR1 catalogue, incorporating the full SFR posterior probability distributions generated by state-of-the-art spectral energy distribution fitting code GRAHSP. This allows us to probabilistically determine a mean SFR – L1.4 relation for the SF dominated galaxies, whilst accounting for changing fractions of SF dominated sources across redshift, radio luminosity and stellar mass ranges. We find that the SFR – radio luminosity correlation exhibits a significant dependence on redshift, but a stellar mass dependence that is weaker than previous studies. Our resultant SFR-radio correlation is log10(SFR/M⊙ yr−1) = 0.790 × (log10(L1.4/W Hz−1) − 23) + 1.244 × (1 + z)0.122 − 0.033 × (log10(M*/M⊙) − 10), with an intrinsic scatter of 0.178 dex. We show that this redshift evolution could be explained by a moderate evolution in the radio spectral index of SF galaxies. We attribute the lack of observed strong dependence on stellar mass, compared to recent studies, to the novel statistical approach that does not rely on cuts to remove AGN.
Versions
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BibTeX
@article{jackson2026mightee,
title = {{A MIGHTEE robust measurement of the star formation rate – radio correlation}},
author = {Charlotte L Jackson and Matt J Jarvis and Imogen H Whittam and James H Matthews and Johannes Buchner and Catherine L Hale and Joel Hamlett and S Lyla Jung and Mara Salvato and Daniel J B Smith and Natalia Stylianou and Rohan G Varadaraj},
journal = {Monthly Notices of the Royal Astronomical Society},
year = {2026},
month = oct,
doi = {10.1093/mnras/stag1947},
url = {https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/stag1947/8943798},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - A MIGHTEE robust measurement of the star formation rate – radio correlation
AU - Charlotte L Jackson
AU - Matt J Jarvis
AU - Imogen H Whittam
AU - James H Matthews
AU - Johannes Buchner
AU - Catherine L Hale
AU - Joel Hamlett
AU - S Lyla Jung
AU - Mara Salvato
AU - Daniel J B Smith
AU - Natalia Stylianou
AU - Rohan G Varadaraj
PY - 2026
DA - 2026/10/19
JO - Monthly Notices of the Royal Astronomical Society
DO - 10.1093/mnras/stag1947
UR - https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/stag1947/8943798
AB - Determining the relationship between star-formation rate (SFR) and the radio luminosity (L1.4) is critical if we are to trace the star-formation history of the Universe dust-agnostically using current and future radio facilities. However, until now, such work has relied on potentially biased binary classifications of sources to remove contaminating active galactic nuclei (AGN). We present a new, statistically-driven methodology for deriving the SFR – L1.4 relation, removing the need for problematic cuts. We use a Bayesian hierarchical mixture model fit to the radio-detected sources in the deep MIGHTEE COSMOS DR1 catalogue, incorporating the full SFR posterior probability distributions generated by state-of-the-art spectral energy distribution fitting code GRAHSP. This allows us to probabilistically determine a mean SFR – L1.4 relation for the SF dominated galaxies, whilst accounting for changing fractions of SF dominated sources across redshift, radio luminosity and stellar mass ranges. We find that the SFR – radio luminosity correlation exhibits a significant dependence on redshift, but a stellar mass dependence that is weaker than previous studies. Our resultant SFR-radio correlation is log10(SFR/M⊙ yr−1) = 0.790 × (log10(L1.4/W Hz−1) − 23) + 1.244 × (1 + z)0.122 − 0.033 × (log10(M*/M⊙) − 10), with an intrinsic scatter of 0.178 dex. We show that this redshift evolution could be explained by a moderate evolution in the radio spectral index of SF galaxies. We attribute the lack of observed strong dependence on stellar mass, compared to recent studies, to the novel statistical approach that does not rely on cuts to remove AGN.
SN - 0035-8711
SN - 1365-2966
ER -