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Scaling relations trace the formation and evolution of galaxy clusters. We exploited multi-wavelength surveys – the XXL survey at XMM-Newton in the X-ray band, and the Hyper Suprime-Cam Subaru Strategic Program for optical weak lensing – to study an X-ray selected, complete sample of clusters and groups. The scalings of gas mass, temperature, and soft-band X-ray luminosity with the weak lensing mass show imprints of radiative cooling and active galactic nucleus feedback in groups. From the multi-variate analysis, we found some evidence for steeper than self-similar slopes for gas mass (⁠|$\beta _{m_\text{g}|m}=1.73 \pm 0.80$|⁠) and luminosity (β l | m  = 1.91 ± 0.94) and a nearly self-similar slope for the temperature (β t | m  = 0.78 ± 0.43). Intrinsic scatters of X-ray properties appear to be positively correlated at a fixed mass (median correlation factor |$\rho _{X_1X_2|m}\sim 0.34$|⁠) due to dynamical state and merger history of the haloes. Positive correlations with the weak lensing mass (median correlation factor |$\rho _{m_\text{wl}X|m}\sim 0.35$|⁠) can be connected to triaxiality and orientation. Comparison of weak lensing and hydrostatic masses suggests a small role played by non-thermal pressure support (⁠|$9\pm 17{{\ \rm per\ cent}}$|⁠). [ABSTRACT FROM AUTHOR]

We present new constraints on the evolution of dark energy from an analysis of cosmic microwave background, supernova and X-ray galaxy cluster data. Our analysis employs a minimum of priors and exploits the complementary nature of these data sets. We examine a series of dark energy models with up to three free parameters: the current dark energy equation of statew0, the early-time equation of statewet, and the scalefactor at transitionat. From a combined analysis of all three data sets, assuming a constant equation of state and that the Universe is flat, we measure. Includingwet as a free parameter and allowing the transition scalefactor to vary over the rangewhere the data sets have discriminating power, we measureand. We find no significant evidence for evolution in the dark energy equation-of-state parameter with redshift. Marginal hints of evolution in the supernovae data become less significant when the cluster constraints are also included in the analysis. The complementary nature of the data sets leads to a tight constraint on the mean matter densityΩm and alleviates a number of other parameter degeneracies, including that between the scalar spectral indexns, the physical baryon densityand the optical depthτ. This complementary nature also allows us to examine models in which we drop the prior on the curvature. For non-flat models with a constant equation of state, we measureand obtain a tight constraint on the current dark energy density. For dark energy models other than a cosmological constant, energy–momentum conservation requires the inclusion of spatial perturbations in the dark energy component. Our analysis includes such perturbations, assuming a sound speedin the dark energy fluid as expected for quintessence scenarios. For our most general dark energy model, not including such perturbations would lead to spurious constraints onwet, which would be tighter than those mentioned above by approximately a factor of 2 with the current data. [ABSTRACT FROM AUTHOR]