Chemical Analysis of Five Red Giants in the Globular Cluster M10 (NGC 6254)

TL;DR

This study analyzes elemental abundances in five red giant stars of the globular cluster M10, revealing moderate metal-poorness, alpha enhancement, and r-process enrichment, using moderate-resolution spectroscopy.

Contribution

It provides detailed elemental abundance measurements for five RGB stars in M10, expanding understanding of its chemical composition and nucleosynthetic history.

Findings

M10 is moderately metal-poor with [Fe/H] = -1.45.

All stars show Al enhancement with <[Al/Fe]> = +0.33.

The cluster is r-process rich with <[Eu/La]> = +0.41.

Abstract

We have determined Al, $\alpha$, Fe-peak, and neutron capture elemental abundances for five red giant branch (RGB) stars in the Galactic globular cluster M10. Abundances were determined using equivalent width analyses of moderate resolution (R$\sim$15,000) spectra obtained with the Hydra multifiber positioner and bench spectrograph on the WIYN telescope. The data sample the upper RGB from the luminosity level near the horizontal branch to about 0.5 mag below the RGB tip. We find in agreement with previous studies that M10 is moderately metal-poor with [Fe/H]=-1.45 ($\sigma$=0.04). All stars appear enhanced in Al with $<$[Al/Fe]$>$=+0.33 ($\sigma$=0.19), but no stars have [Al/Fe]$\ga$+0.55. We find the $\alpha$ elements to be enhanced by +0.20 to +0.40 dex and the Fe--peak elements to have [el/Fe]$\sim$0, which are consistent with predictions from type II SN ejecta. Additionally, the cluster appears to be r-process rich with $<$[Eu/La]$>$=+0.41.