2003/05/19 by Subhabrata Majumdar, Joseph J. Mohr · 12 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Cluster (spacecraft) #Context (archaeology) #Cosmic microwave background #Cosmology and Gravitation Theories #Dark energy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Photometric redshift #Redshift #Spectral density #astro-ph
paper · pdf · doi:10.1086/422829
published as Astrophys.J.613:41-50,2004 · 9 pages, 4 figures, submitted to ApJ
arxiv created 2003/05/19 · openalex publication_date 2004/09/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We examine the prospects for measuring the dark energy equation-of-state parameter w within the context of any uncertain redshift evolution of galaxy cluster structure (building on our earlier work) and show that including the redshift-averaged cluster power spectrum ( cl ) and direct mass measurements of 100 clusters helps tremendously in reducing cosmological parameter uncertainties. Specifically, we show that when combining the redshift distribution and the power spectrum information for a particular X-ray survey ( DUET ) and two Sunyaev-Zel'dovich effect surveys (South Pole Telescope and Planck ), the constraints on the dark energy equation-of-state w can be improved by roughly a factor of 4. Because surveys designed to study the redshift distribution of clusters will have all the information necessary to construct cl , the benefit of adding cl in reducing uncertainties comes at no additional observational cost. Combining detailed mass studies of 100 clusters with the redshift distribution improves the parameter uncertainties by a factor of 3-5. The data required for these detailed mass measurements—assumed to have 1 σ uncertainties of 30%—are accumulating in the XMM-Newton and Chandra archives. The best constraints are obtained when one combines both the power spectrum constraints and the mass measurements with the cluster redshift distribution; when using the survey to extract the parameters and evolution of the mass-observable relations, we estimate uncertainties on w of ~4%-6%. These parameter constraints are possible with cluster surveys that are carried out over large, contiguous regions of the sky, so that the cluster power spectrum can be reasonably measured. In combination with cosmic microwave background or distance measurements that have different parameter degeneracies, cluster studies of dark energy will provide enhanced constraints and allow for cross-checks of systematics.