The Interaction between the XMC Galaxies as seen with abundance gradients – Joshua Povick

Galaxies such as the Milky Way are widely thought to have formed through the hierarchical merging of smaller galaxies. To understand that process, it is crucial to study systems of interacting dwarf galaxies. The Magellanic Clouds (MCs), consisting of the Large and Small Magellanic Clouds (LMC and SMC respectively), are ideal for such studies due to their brightness and proximity. This work investigates the abundance gradients for 20 different elements in the two galaxies using data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE), which observed 6130 red giant branch (RGB) stars in the LMC and 2062 in the SMC. The gradients show a significant change in the chemistry of the MCs, which coincides with a known significant Interaction that occurred about 2 Gyr ago. Initially, the abundance gradients flatten for younger and younger stars, but for stars after the interaction, they become steeper. These findings suggest that abundance gradients offer valuable insights into galactic formation and evolution.