Cluver, M. E.Phillipps, S.Ali, S. S.2021-02-122021-02-122019Cluver, M. E. et al. (2020). Galaxy And Mass Assembly (GAMA): Defining passive galaxy samples and searching for the UV upturn. Monthly Notices of the Royal Astronomical Society, 492(2), 2128–21391365-2966https://doi.org/10.1093/mnras/stz3552http://hdl.handle.net/10566/5908We use data from the GAMA and GALEX surveys to demonstrate that the UV upturn, an unexpected excess of ultraviolet flux from a hot stellar component, seen in the spectra of many early-type galaxies, arises from processes internal to individual galaxies with no measurable influence from the galaxies’ larger environment. We first define a clean sample of passive galaxies without a significant contribution to their UV flux from low-level star formation. We confirm that galaxies with the optical colours of red sequence galaxies often have signs of residual star formation, which, without other information, would prevent a convincing demonstration of the presence of UV upturns. However, by including (NUV−u) and WISE (W2–W3) colours, and FUV data where it exists, we can convincingly constrain samples to be composed of non-star-forming objects. Using such a sample, we examine GALEX photometry of low-redshift GAMA galaxies in a range of low-density environments, from groups to the general field, searching for UV upturns. We find a wide range of (NUV−r) colours, entirely consistent with the range seen – and attributed to the UV upturn – in low-redshift red sequence cluster galaxies.enGalaxies: evolutionGalaxies: star formationGalaxies: stellar contentGalaxy And Mass Assembly (GAMA)UV upturnArticle