Publication details for Dr Russell SmithRawle, T.D., Smith, R.J., Lucey, J.R., Hudson, M.J. & Wegner, G.A. (2008). Near ultraviolet-infrared colours of red-sequence galaxies in local cluster. Monthly notices of the Royal Astronomical Society 385(4): 2097-2106.
- Publication type: Journal Article
- ISSN/ISBN: 0035-8711, 1365-2966
- DOI: 10.1111/j.1365-2966.2008.12967.x
- Keywords: Galaxies: elliptical and lenticular, cD, Galaxies: stellar content, Ultraviolet: galaxies.
- Further publication details on publisher web site
Author(s) from Durham
We present GALEX near-ultraviolet (NUV) and Two-Micron All-Sky Survey J-band photometry for red-sequence galaxies in local clusters. We define quiescent samples according to a strict emission threshold, removing galaxies with very recent star formation. We analyse the NUV–J colour–magnitude relation (CMR) and find that the intrinsic scatter is an order of magnitude larger than for the analogous optical CMR (∼0.35 rather than 0.05 mag), in agreement with previous studies. Comparing the NUV–J colours with spectroscopically derived stellar population parameters, we find a strong (>5.5σ) correlation with metallicity, only a marginal trend with age, and no correlation with the α/Fe ratio. We explore the origin of the large scatter and conclude that neither aperture effects nor the UV upturn phenomenon contribute significantly. We show that the scatter could be attributed to simple ‘frosting’ by either a young or a low-metallicity subpopulation.