A wide-field, multi-line survey of CO in the Magellanic Clouds at parsec-scale resolution: characterising the molecular gas content with a 50-m single-dish submillimeter telescope

TL;DR

This paper advocates for a comprehensive, high-resolution CO survey of the Magellanic Clouds using a large single-dish submillimeter telescope to study molecular gas and galaxy evolution in low-metallicity environments.

Contribution

It proposes a detailed plan for wide-field, multi-line CO mapping of the Magellanic Clouds with a large single-dish telescope, enabling unprecedented insights into molecular gas and star formation.

Findings

Calibrates star-formation laws in low-metallicity environments

Provides benchmarks for high-redshift galaxy studies

Enables detailed molecular cloud lifecycle analysis

Abstract

The Large and Small Magellanic Clouds (LMC, SMC) are nearby dwarf galaxies whose proximity uniquely enables molecular cloud-scale resolution observations across the entire Magellanic system, a capability unmatched in any other external galaxy. Their low metallicities resemble conditions near the peak of cosmic star formation, allowing resolved studies of interstellar medium (ISM) phases, molecular cloud lifecycles, and feedback processes that regulate galaxy evolution. Comprehensive, wide-field spectroscopic mapping of CO and its isotopologues in different transitions, complemented by [CI] observations, and combined with already existing HI and HII surveys, will calibrate star-formation laws and gas-phase partition under low-metallicity conditions and furnish benchmarks for interpreting high-redshift galaxies and cosmological simulations. This science requires a large-aperture, wide-field submillimeter single dish with multi-pixel spectroscopic capabilities, operated from a high, dry site such as Chajnantor, to deliver fast, sensitive, high-resolution, degree-scale mapping with total-power fidelity. We present the case for a full molecular atlas of the Magellanic system, the enabling facility requirements, and the transformative impact on galaxy evolution studies