400d cluster survey

400d is an X-ray survey for galaxy clusters using archival ROSAT observations. It is sensitive to "typical", M ~ 3e14 h−1 Msun, clusters out to z ~ 1 and covers 400 square degrees — essentially all suitable ROSAT pointed data. Our sensitive detection algorithm has produced a statistically complete and uncontaminated cluster sample.

Our catalog contains 242 clusters, all with spectroscopic redshfits. The survey area and volume are carefully calibrated.

A complete subsample of 41 clusters at 0.35 < z < 0.9 was observed with Chandra. These clusters are the basis of our cosmological work. They are also used in several accompanying projects.

News and Updates
Feb-15-2012: updated likelihood grids + cosmoMC module for the 400d cluster sample
Dec-16-2008: Press release on Dark Energy studies with growth of galaxy clusters ... and its video trailer(30M; or in lower quality on youtube)
Dec-15-2008: New paper posted (cosmological constraints --- dark energy equation of state, neutrino mass, and sigma8)
Jun-11-2008: New paper posted (Chandra analysis of the clusters-for-cosmology samples)
Nov-21-2006: New paper posted (cooling flow fraction at high redshifts)
Oct-20-2006: ds9 display links for ROSAT fields and individual clusters (get new version of the ds9 command script).
Oct-5-2006: First release of the website