Galaxy and mass assembly: the 1.4 GHz SFR indicator, SFR–M* relation and predictions for ASKAP–GAMA

Journal article

We present a robust calibration of the 1.4 GHz radio continuum star formation rate (SFR) using a combination of the Galaxy And Mass Assembly (GAMA) survey and the Faint Images of the Radio Sky at Twenty-cm (FIRST) survey. We identify individually detected 1.4 GHz GAMA-FIRST sources and use a late-type, non-AGN, volume-limited sample from GAMA to produce stellar mass-selected samples. The latter are then combined to produce FIRST-stacked images. This extends the robust parametrisation of the 1.4 GHz-SFR relation to faint luminosities. For both the individually detected galaxies and our stacked samples, we compare 1.4 GHz luminosity to SFRs derived from GAMA to determine a new 1.4 GHz luminosity-to-SFR relation with well constrained slope and normalisation. For the first time, we produce the radio SFR-M⇤ relation over 2 decades in stellar mass, and find that our new calibration is robust, and produces a SFR-M⇤relation which is consistent with all other GAMA SFR methods. Finally, using our new 1.4 GHz luminosity-to-SFR calibration we make predictions for the number of star-forming GAMA sources which are likely to be detected in the upcoming ASKAP surveys, EMU and DINGO.

Authors: Davies, L; Huynh, M; Hopkins, A; Seymour, N; Driver, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Oxford University Press
• Journal: Monthly Notices of the Royal Astronomical Society
• Volume: 466
• Issue: 2
• Pages: 2312-2324
• Publication date: 2016-11-01
• Acceptance date: 2016-11-24
• DOI: 10.1093/mnras/stw3080
• ISSN: 0035-8711 and 1365-2966
• Keywords: galaxies: star-formation; radiation mechanisms: non-thermal; galaxies: evolution; radio continuum: galaxies