Age Dating Stellar Populations in the Near Infrared: An absolute age indicator from the presence/absence of red supergiants

TL;DR

This paper introduces a new absolute age indicator for young stellar clusters using near-infrared J-H colour, based on the emergence of red supergiants, enabling age determination around 5.7 million years.

Contribution

The paper presents a novel near-infrared method for age-dating stellar clusters by detecting red supergiants, which improves accuracy and applicability in future IR observations.

Findings

The method accurately distinguishes clusters older or younger than ~5.7 Myr.

Good agreement with theoretical predictions in M83 galaxy.

Potential for future IR space and ground-based applications.

Abstract

The determination of age is a critical component in the study of a population of stellar clusters. In this letter we present a new absolute age indicator for young massive star clusters based on J-H colour. This novel method identifies clusters as older or younger than 5.7 +/- 0.8 Myr based on the appearance of the first population of red supergiant stars. We test the technique on the stellar cluster population of the nearby spiral galaxy, M83, finding good agreement with the theoretical predictions. The localisation of this technique to the near-IR promises that it may be used well into the future with space-- and ground--based missions optimised for near-IR observations.