Abstract
An accurate, spherically symmetric description of the mass distribution is presented for two quite virialized galaxy clusters, Abell 1689 and Abell 1835. A suitable regularization of the small eigenvalues of the covariance matrices is introduced. A stretched exponential profile is assumed for the brightest cluster galaxy. A similar stretched exponential for the dark matter and halo galaxies combined, functions well, as do thermal fermions for the dark matter and a standard profile for the halo galaxies. To discriminate between them, sensitive tests have been identified and applied. A definite verdict can follow from sharp data near the cluster centers and beyond 1 Mpc.
Highlights
In the present era of precision cosmology, various cosmological parameters are known at the percent level, while serious tension remains, in particular, concerning the value of the Hubble parameter [1]
The gas mass density only becomes significant at large r, because the galaxies are dominant at small r
This often employed profile has first been inferred from dark matter-only simulations, and it is often supposed to hold with the baryon density is included
Summary
In the present era of precision cosmology, various cosmological parameters are known at the percent level, while serious tension remains, in particular, concerning the value of the Hubble parameter [1]. In a MOND context, the best developed such proposal is the νHDM framework [19], in which galaxy clusters are explained together with the CMB anisotropies using 11 eV/c2 sterile neutrinos with the same overall density as the CDM in ΛCDM. This framework might account for the Hubble tension [20]. Analysis of clusters puts forward a cross section-to-mass ratio σ/m ∼ 1 cm2/gr [21,22], the question is not settled [23] This large value excludes a lot of parameter space for various models of dark matter.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
