A Careful Reassessment of Globular Cluster Multiple Population Radial Distributions with Sloan Digital Sky Survey and Johnson-Cousins Broadband Photometry

TL;DR

This study re-analyzes globular cluster multiple population radial distributions using SDSS and Johnson-Cousins photometry, correcting previous systematic errors and emphasizing the importance of statistical considerations, revealing less segregation than previously believed.

Contribution

It provides a revised analysis of eight globular clusters' radial distributions, correcting past errors and highlighting the need for improved statistical methods and understanding of multiple population distributions.

Findings

Many multiple populations are less segregated than previously thought

Corrected systematic errors in radial distribution analysis

Emphasized the importance of considering K-S statistic values

Abstract

Inconsistencies regarding the nature of globular cluster multiple population radial distributions is a matter for concern given their role in testing or validating cluster dynamical evolution modeling. In this study, we present a re-analysis of eight globular cluster radial distributions using publicly available ground-based ugriz and UBVRI photometry; correcting for a systematic error identified in the literature. We detail the need for including and considering not only K-S probabilities but critical K-S statistic values as well when drawing conclusions from radial distributions, as well as the impact of sample incompleteness. Revised cumulative radial distributions are presented, and the literature of each cluster reviewed to provide a fuller picture of our results. We find that many multiple populations are not as segregated as once thought, and that there is a pressing need for better understanding of the spatial distributions of multiple populations in globular clusters.