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M. Postman (STScI), H. Ford (JHU), G. Illingworth (UC Lick Obs), M. Franx (Leiden), P. Rosati (ESO), N. Benitez (JHU), T. Broadhurst (Hebrew Univ), J. Blakeslee, C. Gronwall, Z. Tsvetanov, G. Meurer (JHU), G. Miley (Leiden), R. Bouwens (UCSC)
The Advanced Camera for Surveys IDT will perform an extensive survey of galaxy clusters across a large redshift range. The survey will determine the dark matter distribution within galaxy clusters, study cluster galaxy evolution, and probe the high redshift universe using these clusters as powerful cosmic telescopes.
Deep g,r,i,z imaging of a sample of low-z (0.2-0.4) clusters will yield a large sample of lensed background galaxies with reliable photometric redshifts. Using multiple pointings with a central overlap region we will reach HDF-like depth in the central, highly magnified cluster region and shallower, wider coverage in the outer regions. By combining strong and weak lensing constraints with the photometric redshift information we will precisely measure the cluster dark matter distribution with an unprecedented combination of high spatial resolution and area coverage, avoiding many of the uncertainties which plague ground-based studies and yielding definitive answers about the structure of massive dark matter haloes. We expect to detect several highly magnified dropout galaxies behind the clusters in the redshift ranges 4-5, 5-6, and 7-8, corresponding to a drop in the flux in the g,r,and i bands relative to longer wavelength.
New constraints on the evolutionary state of high redshift clusters will be made by obtaining deep multiband images (r,i,z) over the central 1.5 Mpc regions of 7 distant clusters in the range 0.76 < z < 1.27. Slitless spectroscopy, using the WFC GRISM, will be performed over the central 750 kpc region of each system. With these data, we will definitively establish the morphological composition and star formation rates as functions of clustercentric radius, local density, x-ray luminosity. We will also strongly constrain the galaxy merger frequency and the origins of elliptical and S0 galaxies. Lastly, we will image several z>2 radio galaxies in an effort to study massive cluster galaxy formation.
The author(s) of this abstract have provided an email address for comments about the abstract: postman@stsci.edu
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Bulletin of the American Astronomical Society, 34
© 2002. The American Astronomical Soceity.