UV observations of the globular cluster M10 from HST and GALEX. The BSS population

TL;DR

This study combines HST, ground-based, and GALEX data to analyze the structure and Blue Straggler Star population of globular cluster M10, revealing a bimodal BSS distribution and confirming the cluster's density profile fits a King model.

Contribution

The paper provides a comprehensive multi-instrument analysis of M10's structure and BSS distribution, applying the dynamical clock scheme to interpret the cluster's dynamical state.

Findings

Density profile fits a King model with c=1.41 and r_c=41"

BSS population shows a bimodal radial distribution

120 BSS identified within the tidal radius

Abstract

We present a combination of high-resolution Hubble Space Telescope and wide-field ground-based and Galaxy Evolution Explorer data of the Galactic Globular Cluster M10 (NGC6254). By using this large data-set we determined the center of gravity of the cluster and we built its density profile from star counts over its entire radial extension. We find that the density profile is well reproduced by a single-mass King model with structural parameters c=1.41 and r_c=41". We also studied the Blue Straggler Star population and its radial distribution. We count a total number of 120 BSS within the tidal radius. Their radial distribution is bimodal: highly peaked in the cluster center, decreasing at intermediate distances and rising again outwards. We discuss these results in the context of the dynamical clock scheme presented by Ferraro et al. (2012) and of recent results about the radial distribution of binary systems in this cluster.