| Title | Near ultraviolet-infrared colours of red-sequence galaxies in local clusters |
| Authors | Rawle, Timothy D.; Smith, Russell J.; Lucey, John R.; Hudson, Michael J.; Wegner, Gary A. |
| Bibcode | 2008MNRAS.385.2097R Search ADS ↗ |
| Abstract | 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. |
| Objects | 1045 Objects Search NED ↙ |
