Over galactic or molecular cloud scales, low-mass stars far outnumber their high-mass counter parts. As a result, their collective outflows have a significant impact on the total energy budget imparted to the interstellar medium through the process of star formation. In order to properly understand and model the impact of protostellar outflows on both the parent molecular clouds and in galactic evolution it is vital to constrain their origin and exact formation process.
The cold molecular parts of protostellar outflows have long now been studied in great detail in the millimeter regime. The advent of JWST has opened the possibility to study the shock excited hot molecular component of outflows as well as their jets in scales down to a few hundreds of AU from the driving source.
In this talk, I will present JWST MIRI MRS observations of 5 Class I protostars in the Ophiuchus molecular cloud, which is a unique laboratory to study low-mass star formation in a highly-UV irradiated environment. Analysis of the H2 emission in the outflows reveals two separate gas components, a “cold” component with Tex of 300 – 600 K, and a hot component with Tex of 1000 – 3000 K. I will discuss the potential origin of both the molecular H2 as well as that of the various atomic and ionic lines, based on the morphology of the emission and comparisons to UV irradiated shock models. Our sources are exposed to different levels of UV irradiation, due to their varying distance from the nearby OB stars allowing us to explore the impact of external UV radiation onto protostellar outflows. Constraining the impact of the local UV field, is a key step on determining to what extent is star formation influenced by the surrounding environment.