GAMA/H-ATLAS: common star formation rate indicators and their dependence on galaxy physical parameters

Wang, L.; Norberg, P.; Gunawardhana, M.L.P.; Heinis, S.; Baldry, I.K.; Bland-Hawthorn, J.; Bourne, N.; Brough, S.; Brown, M.J.I.; Cluver, M.E.; Cooray, A.; da Cunha, E.; Driver, S.P.; Dunne, L.; Dye, S.; Eales, S.; Grootes, M.W.; Holwerda, B.W.; Hopkins, A.M.; Ibar, E.; Ivison, R.; Lacey, C.; Lara-Lopez, M.A.; Loveday, J.; Maddox, S.J.; Micha?owski, M.J.; Oteo, I.; Owers, M.S.; Popescu, C.C.; Smith, D.J.B.; Taylor, E.N.; Tuffs, R.J.; van der Werf, P.

Abstract

We compare common star formation rate (SFR) indicators in the local Universe in the Galaxy and Mass Assembly (GAMA) equatorial fields (∼160 deg2), using ultraviolet (UV) photometry from GALEX, far-infrared and sub-millimetre (sub-mm) photometry from Herschel Astrophysical Terahertz Large Area Survey, and Hα spectroscopy from the GAMA survey. With a high-quality sample of 745 galaxies (median redshift 〈z〉 = 0.08), we consider three SFR tracers: UV luminosity corrected for dust attenuation using the UV spectral slope β (SFRUV, corr), Hα line luminosity corrected for dust using the Balmer decrement (BD) (SFRH α, corr), and the combination of UV and infrared (IR) emission (SFRUV + IR). We demonstrate that SFRUV, corr can be reconciled with the other two tracers after applying attenuation corrections by calibrating Infrared excess (IRX; i.e. the IR to UV luminosity ratio) and attenuation in the Hα (derived from BD) against β. However, β, on its own, is very unlikely to be a reliable attenuation indicator. We find that attenuation correction factors depend on parameters such as stellar mass (M*), z and dust temperature (Tdust), but not on Hα equivalent width or Sérsic index. Due to the large scatter in the IRX versus β correlation, when compared to SFRUV + IR, the β-corrected SFRUV, corr exhibits systematic deviations as a function of IRX, BD and Tdust.

Citation

Wang, L., Norberg, P., Gunawardhana, M., Heinis, S., Baldry, I., Bland-Hawthorn, J., Bourne, N., Brough, S., Brown, M., Cluver, M., Cooray, A., da Cunha, E., Driver, S., Dunne, L., Dye, S., Eales, S., Grootes, M., Holwerda, B., Hopkins, A., Ibar, E., …van der Werf, P. (2016). GAMA/H-ATLAS: common star formation rate indicators and their dependence on galaxy physical parameters. Monthly Notices of the Royal Astronomical Society, 461(2), 1898-1916. https://doi.org/10.1093/mnras/stw1450

• Journal Article Type: Article
• Acceptance Date: Jun 15, 2016
• Online Publication Date: Jun 20, 2016
• Publication Date: Jun 20, 2016
• Deposit Date: Apr 27, 2017
• Publicly Available Date: Apr 27, 2017
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 461
• Issue: 2
• Pages: 1898-1916
• DOI: https://doi.org/10.1093/mnras/stw1450
• Keywords: methods: statistical, galaxies: photometry, galaxies: statistics, infrared: galaxies, ultraviolet: galaxies
• Public URL: https://nottingham-repository.worktribe.com/output/794268
• Publisher URL: https://academic.oup.com/mnras/article-lookup/doi/10.1093/mnras/stw1450
• Additional Information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
• Contract Date: Apr 27, 2017