The analytic radial acceleration relation for galaxy clusters

TL;DR

This paper derives an analytic radial acceleration relation for galaxy clusters and finds it exhibits large scatter and differences from the galactic relation, questioning its universality.

Contribution

The paper presents the first analytic derivation of the radial acceleration relation for galaxy clusters and compares it with galactic data, revealing significant differences.

Findings

Large scatter in the cluster radial acceleration relation

Partial agreement with galactic relation in certain ranges

Differences in functional form suggest non-universality

Abstract

Recently, a tight correlation between the dynamical radial acceleration and the baryonic radial acceleration in galaxies - the radial acceleration relation - has been discovered. This has been claimed as an indirect support of the modified gravity theories. However, whether the radial acceleration relation could also be found in galaxy clusters is controversial. In this article, we derive and present an analytic radial acceleration relation for the central region of galaxy clusters. We examine the data of some large galaxy clusters and we find that the resulting radial acceleration relation has a very large scatter. Moreover, although the radial acceleration relation for galaxy clusters shows some agreement with the one discovered in galaxies for a certain range of baryonic radial acceleration, their functional forms are somewhat different from each other. This suggests that the radial acceleration relation may not be a universal relation in general.