MAGMA-SMC: The Molecular Cloud Survey of the SMC

Abstract

We present a brief summary and description of the upcoming ¹²CO(1-0) Magellanic Mopra Assesment (MAGMA) SMC survey data release. The MAGMA-SMC survey has sampled 100% of the known CO in the SMC (at ∼33″ resolution; 12 pc at D = 60 kpc). Having explored 522 × 10³ square parsecs throughout the SMC with 69 5′ × 5′ fields, to a sensitivity of ∼150 mK, we apply the cloudprops (Rosolowsky & Leroy 2006) cloud-search algorithm optimized for low S/N data, to detect more than 30 CO clouds with virial masses between 10³–10⁴ M_⊙, mean radii ∼5 pc and 0.3–0.9 km s⁻¹ velocity width. Typical brightness temperatures are ∼1 K T^mb. All detected molecular regions are associated with at least one 24 μm compact emission source. Smoothing rarely increases the total detected CO flux, implying the CO emission is typically confined to small spatial scales. As recent dust maps of the SMC imply extended H₂ mass, the apparent compact nature of the CO population indicates some departures from the canonical Galactic X_CO-factor in the low-metallicity and relatively un-evolved ISM of the SMC.