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Arxiv: PROJECT-J: JWST observations of HH46~IRS and its outflow. Overview and first results Published: 4/10/2024 1:06:48 PM Updated: 4/10/2024 1:06:48 PM

Paper abstract: We present the first results of the JWST program PROJECT-J (PROtostellar JEtsCradle Tested with JWST ), designed to study the Class I source HH46 IRS andits outflow through NIRSpec and MIRI spectroscopy (1.66 to 28 micron). The dataprovide line-images (~ 6.6" in length with NIRSpec, and up to 20" with MIRI)revealing unprecedented details within the jet, the molecular outflow and thecavity. We detect, for the first time, the red-shifted jet within ~ 90 au fromthe source. Dozens of shock-excited forbidden lines are observed, includinghighly ionized species such as [Ne III] 15.5 micron, suggesting that the gas isexcited by high velocity (> 80 km/s) shocks in a relatively high densitymedium. Images of H2 lines at different excitations outline a complex molecularflow, where a bright cavity, molecular shells, and a jet-driven bow-shockinteract with and are shaped by the ambient conditions. Additional NIRCam 2micron images resolve the HH46 IRS ~ 110 au binary system and suggest that thelarge asymmetries observed between the jet and the H2 wide angle emission couldbe due to two separate outflows being driven by the two sources. The spectra ofthe unresolved binary show deep ice bands and plenty of gaseous lines inabsorption, likely originating in a cold envelope or disk. In conclusion, JWSThas unraveled for the first time the origin of the HH46 IRS complex outflowdemonstrating its capability to investigate embedded regions around youngstars, which remain elusive even at near-IR wavelengths.