A test of Radial Acceleration Relation for the {\it Giles et al Chandra} cluster sample

TL;DR

This study tests the radial acceleration relation (RAR) in galaxy clusters using Chandra X-ray data, finding a tight correlation with an acceleration scale higher than in galaxies, suggesting the RAR may be emergent rather than universal.

Contribution

It provides the first detailed test of the RAR in galaxy clusters, revealing differences from galaxy-scale RAR parameters and questioning its universality.

Findings

RAR shows a tight residual scatter of 0.09 dex in clusters

The acceleration scale is about ten times higher than in galaxies

RAR parameters differ from previous cluster studies

Abstract

We carry out a test of the radial acceleration relation (RAR) for a sample of 10 dynamically relaxed and cool-core galaxy clusters imaged by the Chandra X-ray telescope, which was studied in Giles et al. For this sample, we observe that the best-fit RAR shows a very tight residual scatter equal to 0.09 dex. We obtain an acceleration scale of $1.59 \times 10^{-9} m/s^2$, which is about an order of magnitude higher than that obtained for galaxies. Furthermore, the best-fit RAR parameters differ from those estimated from some of the previously analyzed cluster samples, which indicates that the acceleration scale found from the RAR could be of an emergent nature, instead of a fundamental universal scale.