What's sculpting the Brick?

Jonathan Henshaw

Poster -- Molecular clouds and filaments

The Central Molecular Zone (CMZ) of the Milky Way (i.e. the inner ~500 pc) plays host to some of the Galaxy's most massive molecular clouds and star clusters, and offers an important window into star formation under extreme physical conditions. In this contribution I will describe our new and comprehensive description of the kinematics and internal dynamics of G0.253+0.016; one of the most massive and dense molecular clouds in the Galaxy to not display the advanced signatures of widespread star formation. As potential host to a future generation of high-mass stars, understanding quiescent molecular clouds such as G0.253+0.016 is of critical importance to star formation research. I will present our (re)analysis of ALMA cycle 0 data, using two new pieces of software which we have made publicly available to the community. First, a reimplementation of the spectral line fitting algorithm SCOUSE, first presented in Henshaw+ 2016, and second, ACORNS; a hierarchical clustering algorithm designed for use with discrete spectroscopic data. Combining our kinematic decomposition with radiative transfer modelling we conclude that G0.253+0.016 is not a centrally-concentrated, monolithic molecular cloud with widespread depletion in its cold interior, as had been previously argued. Moreover, we dispute evidence to suggest that the cloud has formed via cloud-cloud collisions. Instead, the morphology of G0.253+0.016 is most likely a product of its dynamic environment; it is a complex and highly sub-structured molecular cloud sculpted by the tangled interplay of both Galactic dynamics and feedback.

Background image: Robert Hurt, IPAC