Abstract

Several processes – including accretion of material onto the central star, planet formation, and winds – all contribute to dispersing protoplanetary discs within the first few millions theirs of their host star’s lifetime. To date, however, observations have not been able to conclusively quantify the contribution of winds. I will discuss two modelling efforts to predict emission from winds and how this might be used to learn about their launching mechanisms. Firstly, the MIRI instrument of JWST may be able to resolve the emission from atomic forbidden lines in the infrared, allowing us to constrain the heating and ionisation of the outflowing material. Using simple prescriptions for a photoevaporative wind structure, we can cheaply explore the parameter space to discover which parts of the winds this emission probes and what its morphology might reveal about their nature. Secondly, winds that effectively remove material from the outermost regions of protoplanetary discs are also induced by nearby massive stars; this material, however, does not have a homogeneous composition due to molecular freeze out and transport on dust grains. Using a 1D disc evolution code we are exploring when this leads to winds with depleted metal abundances and the potential consequences for observing wind emission and hence constraining disc dispersal by external photoevaporation.