Probes of superclusters at moderate redshifts

Abstract

Detection of superclusters at z = 0.2 - 1.0 and determination of their mass provide constraints on the theories of structure formation in the Universe. A combination of the study of hot gas observed in X-rays, and the distribution of arcs (weak lensing of background galaxies) in optical can probe clusters of galaxies as well as superclusters. We have analysed the available X-ray and optical maps of a cluster pair of Abell 222 & Abell 223 at redshift ~- 0.2, separated by ~15' and where at least one arc has been reported. X-ray temperature of the gas in the two clusters is 4 +/- 2 keV and a bridge of hot gas at temperature of ~- 2keV connects them. The bridge is also seen in the optical indicating the presence of a supercluster structure.