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Morphology-dependent trends of galaxy age with environment in Abell 901/902 seen with COMBO-17

C. Wolf·M. E. Gray·A. Aragon-Salamanca·K. P. Lane·K. Meisenheimer
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Abstract

We investigate correlations between galaxy age and environment in the Abell 901/2 supercluster for separate morphologies. Using COMBO-17 data, we define a sample of 530 galaxies, complete at $M_V -5\log h<-18$ on an area of $3.5\times 3.5$ (Mpc/$h$)$^2$. We explore several age indicators including an extinction-corrected residual from the colour-magnitude relation (CMR). As a result, we find a clear trend of age with density for galaxies of all morphologies that include a spheroidal component, in the sense that galaxies in denser environments are older. This trend is not seen among Scd/Irr galaxies since they all have young ages. However, the trend among the other types is stronger for fainter galaxies. While we also see an expected age-morphology relation, we find no evidence for a morphology-density relation at fixed age.

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C. Wolf, M. E. Gray, A. Aragon-Salamanca, K. P. Lane, K. Meisenheimer. 2006-11-30. Morphology-dependent trends of galaxy age with environment in Abell 901/902 seen with COMBO-17. https://doi.org/10.1111/j.1745-3933.2006.00272.x

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