The Lazy Giants: APOGEE Abundances Reveal Low Star Formation Efficiencies in the Magellanic Clouds

Understand

We report the first APOGEE metallicities and alpha-element abundances measured for 3600 red giant stars spanning a large radial range of both the Large (LMC) and Small Magellanic Clouds (SMC), the largest Milky Way dwarf galaxies.

• Our sample is an order of magnitude larger than that of previous studies, and extends to much larger radial distances.
• These are the first results presented that make use of the newly installed Southern APOGEE instrument on the du Pont telescope at Las Campanas Observatory.
• Our unbiased sample of the LMC spans a large range in metallicity, from [Fe/H]=-0.2 to very metal-poor stars with [Fe/H]=-2.5, the most metal-poor Magellanic Clouds (MCs) stars detected to date.