RXJ1131−1231 marginalized posterior PDF for H ₀, Ω _de , and w in flat wCDM cosmological models. Contours/shades mark the 68.3%, 95.4%, 99.7% credible regions. The three sets of contours/shades correspond to three different prior/data set combinations. Shaded red: RXJ1131−1231 constraints given by the U wCDM prior; dashed blue: the prior provided by the WMAP7 data set alone; solid black: the joint constraints from combining WMAP7 and RXJ1131−1231.