Protostellar jets and outflows play a critical role in the interstellar medium (ISM) of galaxies, in which they input energy in all possible forms: mechanical through the shock waves they are associated with, far-UV photons from the protostar or from the fastest shocks, and cosmic rays (CRs) that can be locally accelerated. They hence play an important role in the ISM evolution. In this talk, I will show how SOFIA/GREAT has allowed us, since the launching of this mission, to progress in our understanding of the protostellar outflow Cepheus E driven by an intermediate mass proto-star. I will show how the combination of SOFIA/GREAT data with observations from other telescopes (mostly Plateau de Bure interferometer, Herschel, JCMT, and IRAM-30m) enabled us to constrain the physical components in the various shock structures of the outflow (jet, outflow cavity, and terminal bow-shocks). In turn, this allowed us to identify a favourable scenario for the formation of the outflow. Finally, the comparison of shock models with our observational dataset allowed us to progress on our understanding of shocks in the jet component of the outflow. I will also present detailed perspectives on studies of this object in terms of astrochemistry and cosmic-ray acceleration.
A SOFIA/GREAT View on the Cepheus E Outflow from an Intermediate-Mass Proto-Star