A Bayesian Analysis of the Ages of Four Open Clusters

TL;DR

This paper introduces a Bayesian Markov chain Monte Carlo method to precisely determine the ages of four open clusters by fitting stellar evolution models, surpassing traditional visual methods in accuracy.

Contribution

The paper presents a novel Bayesian approach using MCMC for isochrone fitting, providing higher precision age estimates for open clusters.

Findings

Ages of clusters determined with high precision.

Bayesian method outperforms traditional 'by-eye' fitting.

Cluster ages: NGC 2360: 1.35 Gyr, NGC 2477: 1.02 Gyr, NGC 2660: 1.64 Gyr, NGC 3960: 0.86 Gyr.

Abstract

In this paper we apply a Bayesian technique to determine the best fit of stellar evolution models to find the main sequence turn off age and other cluster parameters of four intermediate-age open clusters: NGC 2360, NGC 2477, NGC 2660, and NGC 3960. Our algorithm utilizes a Markov chain Monte Carlo technique to fit these various parameters, objectively finding the best-fit isochrone for each cluster. The result is a high-precision isochrone fit. We compare these results with the those of traditional "by-eye" isochrone fitting methods. By applying this Bayesian technique to NGC 2360, NGC 2477, NGC 2660, and NGC 3960, we determine the ages of these clusters to be 1.35 +/- 0.05, 1.02 +/- 0.02, 1.64 +/- 0.04, and 0.860 +/- 0.04 Gyr, respectively. The results of this paper continue our effort to determine cluster ages to higher precision than that offered by these traditional methods of isochrone fitting.