No Heavy Element Dispersion in the Globular Cluster M92

TL;DR

This study finds no significant dispersion in heavy element abundances among red giants in M92, confirming a uniform r-process signature and challenging claims of large abundance variations.

Contribution

The paper demonstrates that the observed dispersion in heavy element abundances in M92 is within measurement uncertainties, refuting previous claims of large dispersion.

Findings

Heavy element abundances are consistent across sampled stars.

Abundance ratios match those of M30, indicating similar nucleosynthesis history.

Dispersion does not exceed measurement uncertainties.

Abstract

Although there have been recent claims that there is a large dispersion in the abundances of the heavy neutron capture elements in the old Galactic globular cluster M92, we show that the measured dispersion for the absolute abundances of four of the rare earth elements within a sample of 12 luminous red giants in M92 (less than or equal to 0.07 dex) does not exceed the relevant sources of uncertainty. As expected from previous studies, the heavy elements show the signature of the r-process. Their abundance ratios are essentially identical to those of M30, another nearby globular cluster of similar metallicity.