EDP Sciences
Free access
Volume 425, Number 3, October III 2004
Page(s) 783 - 796
Section Cosmology (including clusters of galaxies)
DOI http://dx.doi.org/10.1051/0004-6361:20035841

A&A 425, 783-796 (2004)
DOI: 10.1051/0004-6361:20035841

Galaxy evolution in the environment of ABCG 209

C. P. Haines1, A. Mercurio1, 2, P. Merluzzi1, F. La Barbera1, M. Massarotti1, G. Busarello1 and M. Girardi2

1  Osservatorio Astronomico di Capodimonte, v. Moiariello 16, 80131 Napoli, Italy
    e-mail: chris@na.astro.it
2  Departimemto di Astronomia, Università degli Studi di Trieste, v. Tiepolo 11, 34100 Trieste, Italy

(Received 10 December 2003 / Accepted 19 May 2004)

We examine the environmental effects on the photometric properties of galaxies for the rich galaxy cluster ABCG 209 at  z=0.209. We use archive CFHT optical imaging of a $42\times28\,{\rm arcmin}^{2}$ field centred on the cluster to produce a galaxy sample complete to  B=25.0 and  R=24.5. Both the composite and red sequence galaxy luminosity functions are found to be dependent on the local galaxy surface density, their faint-end slopes becoming shallower with increasing density. We explain this as a combination of the morphology-density relation, and dwarf galaxies being cannibalised and/or disrupted by the cD galaxy and the ICM in the cluster core. The  B-R colour of the red sequence itself appears 0.02 mag redder for the highest-density regions, indicative of their stellar populations being marginally ( < 5%) older or ( < 20%) more metal-rich. This may be due to the galaxies themselves forming earliest in the rarest overdensities marked by rich clusters, or their star-formation being suppressed earliest by the ICM.

Key words: galaxies: clusters: individual: Abell 209 -- galaxies: luminosity function, mass fuction -- galaxies: evolution

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