Constraints on dark energy from the observed growth of X-ray luminous galaxy clusters

Adam Mantz (KIPAC/Stanford) , Steve Allen (KIPAC), Harald Ebeling (IfA, U. Hawaii), David Rapetti (KIPAC)

I will present cosmological constraints obtained from measurements of the growth of cosmic structure in the most X-ray luminous galaxy clusters in the universe. Our results are consistent with the cosmological constant model and are in good agreement with findings from a variety of independent data, notably the cosmic microwave background (CMB), type Ia supernovae (SNIa), galaxy cluster gas-mass fraction (f_gas), cosmic shear, and galaxy redshift surveys. Using the growth of structure data alone, we find the dark energy equation of state for a constant-w model; this result is remarkably insensitive to the choice of priors and to systematic uncertainties in the analysis. The combination of growth of structure data with CMB, SNIa and f_gas data has the potential to significantly improve constraints on dark energy by breaking a key degeneracy between and w.