The dark matter environment of the Abell 901/902 supercluster: a weak lensing analysis of the HST STAGES survey
Publication date: 08 January 2008
Authors: Heymans, C. et al.
Journal: To appear in MNRAS
Copyright: Royal Astronomical SocietyWe present a high resolution dark matter reconstruction of the z = 0.16 Abell 901/902 supercluster from a weak lensing analysis of the STAGES HST survey. We detect the four main structures of the supercluster at high significance, resolving substructure within and between the clusters. We find that the distribution of dark matter is well traced by the cluster galaxies, with the brightest cluster galaxies marking out the strongest peaks in the dark matter distribution. We also find a significant extension of the dark matter distribution of Abell 901a in the direction of an infalling X-ray group Abell 901-alpha. We present mass, mass-to-light and massto-stellar mass ratio measurements of the structures and substructures that we detect. We find no evidence for variation of the mass-to-light and mass-to-stellar mass ratio between the different clusters. We compare our space-based lensing analysis with an earlier ground-based lensing analysis of the supercluster to demonstrate the importance of space-based imaging for future weak lensing dark matter 'observations'.