Description
Molecular clouds are stellar nurseries, vast clouds of dense dust and gas in which stars and their associated planetary systems form. Instabilities within the cloud manifest in the creation of localised cores of higher density, the interiors of which are under conditions favourable to the ubiquitous formation of icy mantles on dust grain surfaces. The main carbon isotope $^{12}\textrm{C}$ and its weaker counterpart $^{13}\textrm{C}$, are readily detected in ices observed towards molecular clouds and dense core environments. The abundance ratio of these isotopologues is initially set by their different origins. Models have demonstrated that the expected $^{12}\textrm{C}/^{13}\textrm{C}$ ratios of various species are sensitive to the chemical evolution time in prestellar cores and moderately dense clouds. As such, any deviations in the $^{12}\textrm{C}/^{13}\textrm{C}$ ratio from the value derived for the local interstellar medium (ISM) reflects the formation pathway and subsequent chemical evolution of carbon-bearing ice. In the era of JWST, we benefit from access to an unrivalled sensitivity and multiplexing capabilities which allows us to observe ice absorption against the continua of background stars towards hundreds to thousands of sightlines in the molecular cloud. I will present JWST observations towards the Chameleon I molecular cloud complex, tracing the $^{12}\textrm{C}/^{13}\textrm{C}$ ratio across star forming regions of varying evolutionary state, probing the chemical environment with high spatial and spectral resolution.
