Speaker
Description
We present an initial analysis of emission from vibrationally excited molecules of cyanoacetylene (HC3N) in the NGC 253 starburst nucleus. As one of the nearest examples of a nuclear starburst ($D=3.5$ Mpc), the NGC 253 nucleus is a prime candidate for a detailed study of the physical conditions of an extreme star formation environment. The majority of the star formation activity in the central 200 pc of NGC 253 is concentrated in compact and embedded super star clusters (SSCs) which typically have radii of < 5 pc and masses of $10^5$ solar masses. The SSCs are deeply embedded and thus the star formation activity is almost invisible when observed in the optical and near infrared wavelengths due to extinction. To combat this, we utilize the Atacama Large Millimeter/sub-millimeter Array (ALMA) which provides observations of NGC 253 at the sensitivity, resolution, and wavelengths needed to peer into the clusters and constrain the process of massive cluster formation. The formation of such massive and compact clusters in the present day universe is rare. This mode of star formation was much more common in the early Universe, so these clusters are being extensively studied as a prototype for the starburst phase in galactic evolution. In this work, we use high-resolution (< 5 pc) ALMA observations in Bands 3 (84 GHz) and 7 (350 GHz) to isolate the emission from individual clusters. The purpose of this work is to use HC3N to measure the physical properties of the gas inside these forming SSCs, where other wavelengths cannot penetrate, in order to understand the structure of these star formation powerhouses. The ultimate goal of this initial work is to better characterize the formation and evolution of SSCs, and how this may be different from typical star formation in the present-day universe.
