The Omega_M-Omega_Lambda Constraint from CNOC Clusters

Carlberg, R. G.; Yee, H. K. C.; Ellingson, E.; Morris, S. L.; Lin, H.; Sawicki, M.; Patton, D.; Wirth, G.; Abraham, R.; Gravel, P.; Pritchet, C. J.; Smecker-Hane, T.; Schade, D.; Hartwick, F. D. A.; Hesser, J. E.; Hutchings, J. B.; Oke, J. B.

The Omega_M-Omega_Lambda Constraint from CNOC Clusters

Authors

Description

The CNOC redshift survey of galaxy clusters measures Omega_M from Omega_e(z)= M/L x j/ρ_c which can be applied on a cluster-by-cluster basis. The mass-to-light ratios, M/L, are estimated from rich galaxy clusters, corrected to the field population over the 0.18 to 0.55 redshift range. Since the luminosity density depends on cosmological volumes, the resulting Omega_e(z) has a strong dependence on cosmology which allows us to place the results in the Omega_M-Omega_Lambda plane. The resulting Omega_M declines if Omega_Lambda>0 and we find that Omega_Lambda<1.5.
4 pages LaTeX. To appear in "Fundamental Parameters in Cosmology," the proceedings of the XXXIIIrd Rencontres de Moriond