AGB Stars in WLM

TL;DR

This study uses wide-field near-infrared imaging to analyze the star formation history, metallicity, and AGB star populations in the dwarf galaxy WLM, providing new distance estimates and metallicity maps.

Contribution

It offers a new distance measurement, detailed metallicity distribution, and characterization of AGB stars in WLM using JHK photometry and SED analysis.

Findings

Tip of the red giant branch identified for distance estimation

Surface metallicity map created from C/M ratio

Multi-wavelength SEDs constructed for AGB stars

Abstract

We investigate the star formation history and metallicity of the Local Group irregular dwarf galaxy WLM using wide-field JHK near-infrared imaging, spanning a region of approximately 1 sq. degree, obtained with WFCAM on UKIRT. JHK photometry clearly reveals the tip of the red giant branch, allowing a new estimate of the distance, and allows ready identification of C-type and M-type AGB stars. The C/M ratio was used to produce a surface map of the metallicity distribution which is compared to previous studies. Multi-wavelength spectral energy distributions (SEDs) were constructed for some AGB stars.