Galaxy And Mass Assembly: The 1.4GHz SFR indicator, SFR-M relation and predictions for ASKAP-GAMA

• Published in: arXiv.org 2017-01
• Main Authors: Davies, L J M, Huynh, M T, Hopkins, A M, Seymour, N, Driver, S P, Robotham, A G R, Baldry, I K, Bland-Hawthorn, J, Bourne, N, Bremer, M N, Brown, M J I, Brough, S, Cluver, M, Grootes, M W, Jarvis, M, Loveday, J, Moffet, A, Owers, M, Phillipps, S, Sadler, E, Wang, L, Wilkins, S, Wright, A
• Format: Article
• Language: English
• Subjects: Active galactic nuclei; Assembly; Calibration; Galaxies; Luminosity; Parameterization; Radio; Robustness; Sky surveys (astronomy); Star & galaxy formation; Star formation rate; Stellar mass
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1701.06242

We present a robust calibration of the 1.4GHz 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 1.4GHz 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 1.4GHz-SFR relation to faint luminosities. For both the individually detected galaxies and our stacked samples, we compare 1.4GHz luminosity to SFRs derived from GAMA to determine a new 1.4GHz 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 1.4GHz 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.