Cosmological constraints on the hot gas fraction in galaxy clusters [CEA]

http://arxiv.org/abs/1706.07321


The evolution of the X-ray emitting gas mass fraction in massive galaxy clusters can be used as an independent cosmological tool to probe the expansion history of the Universe. Its use, however, depends upon a crucial quantity, i.e., the depletion factor $\gamma$, which corresponds to the ratio by which the X-ray emitting gas fraction in galaxy clusters is depleted with respect to the universal baryonic mean. Since this quantity is not directly observed, assumptions about the cosmology need to be made and usually hydrodynamical cosmological simulations are used to calibrate it. In this letter, we obtain for the first time self-consistent observational constraints on the gas depletion factor combining 40 X-ray emitting gas mass fraction measurements and 580 distance measurements from type Ia supernovae. Using non-parametric methods to reconstruct a possible redshift evolution of $\gamma$, we find no evidence for such evolution, which confirms the current results from hydrodynamical simulations.

Read this paper on arXiv…

R. Holanda, V. Busti, J. Gonzalez, et. al.
Fri, 23 Jun 17
6/48

Comments: 5 pages, 1 figure, 1 table