The Morpho-Kinematic Architecture of Super Star Clusters in the Center of NGC253
The center of the nearby galaxy NGC253 hosts a population of more than a dozen super star clusters (SSCs) which are still in the process of forming. The majority of the star formation of the burst is concentrated in these SSCs, and the starburst is powering a multiphase outflow from the galaxy. In this work, we combine multiple datasets from ALMA to measure the 350 GHz dust continuum emission towards the center of NGC253. We report the detection of 350 GHz continuum emission associated with the SW streamer of the outflow for the first time. The dust emission is located at the outer edge of the CO emission and corresponds to a molecular gas mass of ~10^6.5 M⊙ Using 350 GHz continuum data with 47 milliarcsecond (0.8 pc) resolution, we measure the resolved radial profiles, sizes, and molecular gas masses of the SSCs. In projection, the SSCs appear as a thin, almost linear, structure roughly 170 pc in length and are connected by dust and molecular gas. This structure is on the same scale as inner x2 orbits, which may explain why gas concentrates here, resulting in the current burst of star formation. We constrain the morpho-kinematic arrangement of the SSCs themselves, finding that a model of an elliptical, angular momentum conserving ring is a good description of the morphology and kinematics of the SSCs. This model, and its connection to the x2 orbits, predicts an age gradient in the SSCs which can be measured with future JWST observations.