Garret Cotter

Abstract:

Searches for statistical overdensities of radio sources in the NRAO VLA Sky Survey (NVSS) survey have led to the detection of high redshift clusters of galaxies (Cotter et al. 2002; Croft et al. 2001). We have carried out a similar search for overdensities using the Sydney University Molonglo Sky Survey (SUMSS). Radio observations at 20/13 cm have been made of these candidates at the Australia Telescope Compact Array (ATCA) revealing sources of diffuse cluster emission as well as groups of FR1 sources showing structures associated with clusters, indicating a cluster "hit-rate" of about 70%.

Abstract:

Statistical overdensities of radio sources in the Sydney University Molonglo Sky Survey (SUMSS) are used as signposts to identify high-redshift clusters of galaxies. These potential clusters have been observed at 20 and 13 cm at the Australia Telescope Compact Array (ATCA) to obtain better positional accuracy for the sources. A subsample have been imaged in V, R and I at the 2.3-m telescope at Siding Spring and in J and K at the Anglo Australian Telescope (AAT) and the New Technology Telescope (NTT) at La Silla, Chile. The colours obtained from these observations will be used to estimate redshifts for the potential cluster members. © 2003 Elsevier B.V. All rights reserved.