Stellar Populations and Molecular Gas Composition in the Low-Metallicity Environment of WLM

Haylee N. Archer; Deidre A. Hunter; Bruce G. Elmegreen; Leslie K. Hunt; Rosalia O'brien; Elias Brinks; Phil Cigan; Monica Rubio; Rogier A. Windhorst; Rolf A. Jansen; Elijah P. Mathews

arXiv · 2503.23517

Stellar Populations and Molecular Gas Composition in the Low-Metallicity Environment of WLM

Haylee N. Archer·Deidre A. Hunter·Bruce G. Elmegreen·Leslie K. Hunt·Rosalia O'brien·Elias Brinks·Phil Cigan·Monica Rubio·Rogier A. Windhorst·Rolf A. Jansen·Elijah P. Mathews

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Abstract

We investigate the stellar populations and molecular gas properties of a star-forming region within the dwarf irregular (dIrr) galaxy WLM. Low-metallicity dIrrs like WLM offer a valuable window into star formation in environments that are unlike those of larger, metal-rich galaxies such as the Milky Way. In these conditions, carbon monoxide (CO), typically used to trace molecular clouds, is more easily photodissociated by ultraviolet (UV) radiation, leading to a larger fraction of CO-dark molecular gas, where H$_2$ exists without detectable CO emission, or CO-dark gas in the form of cold HI. Understanding the molecular gas content and the stellar populations in these star-forming regions provides important information about the role of CO-bright and CO-dark gas in forming stars.

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Haylee N. Archer, Deidre A. Hunter, Bruce G. Elmegreen, Leslie K. Hunt, Rosalia O'brien, Elias Brinks, Phil Cigan, Monica Rubio, Rogier A. Windhorst, Rolf A. Jansen, Elijah P. Mathews. 2025-03-30. Stellar Populations and Molecular Gas Composition in the Low-Metallicity Environment of WLM. https://arxiv.org/abs/2503.23517

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