Discovery of metal-poor and distant pre-main sequence candidates in WLM with JWST

TL;DR

This paper reports the discovery of the most distant and metal-poor pre-main sequence stars in the galaxy WLM using JWST, providing new insights into star formation in low-metallicity environments.

Contribution

It identifies twelve metal-poor, distant PMS candidates in WLM, the most distant and metal-poor known, with detailed properties derived from JWST observations.

Findings

Discovered twelve metal-poor PMS candidates in WLM.

Candidates are the most distant and metal-poor PMS stars known.

Candidates are concentrated in a small cluster within an HII region.

Abstract

We present the discovery of twelve metal-poor and distant pre-main sequence (PMS) candidates in the dwarf irregular galaxy Wolf-Lundmark-Melotte (WLM)~968 kpc away, at a present-day metallicity of [Fe/H] around $-$0.9. These candidates have masses between 1.25-5 M$_{\odot}$, with ages <10 Myr, and exhibit significant near-infrared excesses at 2.5 and 4.3 $\mu$m. They are concentrated within a cluster roughly 10 pc (2'') across situated in the HII region [HM95]-9. These are the most distant and metal-poor PMS stars known, and can offer new quantitative insights into star formation at low-metallicities.