Mike Hudson (PI
Roger Davies (Durham)
John Lucey (Durham)
David Schade (CADC/HIA)
Russell Smith (U Catolica de Chile)
Nick Suntzeff (CTIO)
Gary Wegner (Dartmouth)
(Mike Hudson is now the PI of this Survey Project following Jeff Willick's tragic death.)
The peculiar velocity field is the only probe of the mass distribution on large scales (>~ 10 h-1 Mpc) in the nearby Universe. In particular, the bulk flow of the local volume with respect to the CMB probes the very largest scales. Some recent bulk flow results are apparently in conflict, possibly due to the systematics arising from the wide range of instrumentation used by the different groups.
We propose a deep, homogeneous, all-sky spectroscopic and photometric study of 100 X-ray selected clusters within 200 h-1 Mpc. Using the Fundamental Plane distance indicator, we will make an independent determination of the large-scale flow of clusters of galaxies with respect to the CMB. With 4000 early-type galaxies (a factor of 5 increase over current FP surveys), we expect combined random and systematic errors to be <~ 120 km/s for each component of the bulk flow vector. This goal can only be accomplished by a survey program which guarantees access to identical instrumentation over the course of the survey. The resulting photometric and spectroscopic database will be a unique and valuable resource to the community for studies of galaxy morphology, stellar populations and galaxy evolution in the cluster environment.