Imprint of the galactic acceleration scale on globular cluster systems: Galaxies in the Fornax Cluster

TL;DR

This study finds that the distribution of globular clusters around galaxies in the Fornax Cluster exhibits breaks at the galactic acceleration scale $a_0$, consistent across galaxy types and GC sub-populations, indicating a fundamental link between galaxy dynamics and GC system structure.

Contribution

It demonstrates that the correlation between $a_0$-radii and GC system break radii extends to Fornax Cluster galaxies, confirming a universal pattern previously observed in early-type galaxies.

Findings

Break radii of GC systems align with $a_0$-radii across galaxy types.

Red and blue GC sub-populations both show this alignment.

Supports the idea of a fundamental galactic acceleration scale influencing GC distributions.

Abstract

Dark matter is required in galaxies at galactocentric radii that are larger than the $a_0$-radius, which is where the gravitational acceleration generated by baryons of the galaxy equals the constant $a_0=1.2\times 10^{-10}$ms$^{-2}$ known as the galactic acceleration scale. It was found previously for massive early-type galaxies that the radial number-density profiles of their globular cluster (GC) systems follow broken power laws and the breaks occur at the $a_0$-radii. We have newly analyzed the distribution of GCs around galaxies in the Fornax cluster in existing photometric catalogs. We found that 1) the coincidence between $a_0$-radii and the break radii of globular cluster systems is valid for early-type galaxies of all masses and, 2) this also applies to the red and blue sub-populations of GCs separately.