2003/09/17 by J. A. Stevens, R. J. Ivison, J. S. Dunlop +6
Physics and Astronomy · #astro-ph
published as Nature 425 (2003) 264 · 13 pages, 4 figures (1 colour, resolution degraded - gzipped high res version available at http://www.roe.ac.uk/~rji/figure1.ps.gz)
arxiv created 2003/09/17 · arxiv updated 2009/12/01
The most massive galaxies in the present-day Universe are found to lie in the centres of rich clusters. They have old, coeval stellar populations suggesting that the bulk of their stars must have formed at early epochs in spectacular starbursts - luminous phenomena at submillimetre wavelengths. The most popular model of galaxy formation predicts that these galaxies form in proto-clusters at high-density peaks in the early Universe. Such peaks are signposted by massive high-redshift radio galaxies. Here we report deep submillimetre mapping of seven high-redshift radio galaxies and their environments. These data confirm not only the presence of spatially extended massive star-formation activity in the radio galaxies themselves, but also in companion objects previously undetected at any wavelength. The prevalence, orientation, and inferred masses of these submillimetre companion galaxies suggest that we are witnessing the synchronous formation of the most luminous elliptical galaxies found today at the centres of rich galaxy clusters.