Planck-ESZ gas fraction sample

In particular we find evidence at 3.8{sigma} for a redshift dependence of the bias when assuming a Planck prior on Omega_m_. On the other hand, assuming a constant mass bias would lead to the extremely large value of Omega_m_>0.860. We show, however, that our results are entirely dependent on the cluster sample under consideration.

In particular, the mass and redshift trends that we find for the lowest mass-redshift and highest mass-redshift clusters of our sample are not compatible. In addition, we show that assuming self-similarity in our study can impact the results on the evolution of the bias, especially with regard to the mass evolution. Nevertheless, in all the analyses, we find a value for the amplitude of the bias that is consistent with B~0.8, as expected from hydrodynamical simulations and local measurements.

However, this result is still in tension with the low value of B~0.6 derived from the combination of cosmic microwave background primary anisotropies with cluster number counts.