Investigating Protostellar Accretion-driven Outflows across the Mass Spectrum: JWST NIRSpec Integral Field Unit 3–5 μm Spectral Mapping of Five Young Protostars

Abstract

Investigating Protostellar Accretion is a Cycle 1 JWST program using the NIRSpec+MIRI integral field units to obtain 2.9–28 μ m spectral cubes of five young protostars with luminosities of 0.2–10,000 L _⊙ in their primary accretion phase. This paper introduces the NIRSpec 2.9–5.3 μ m data of the inner 840–9000 au with spatial resolutions from 28 to 300 au. The spectra show rising continuum emission; deep ice absorption; emission from H _2 , H i , and [Fe ii ]; and the CO fundamental series in emission and absorption. Maps of the continuum emission show scattered light cavities for all five protostars. In the cavities, collimated jets are detected in [Fe ii ] for the four <320 L _⊙ protostars, two of which are additionally traced in Br α . Knots of [Fe ii ] emission are detected toward the most luminous protostar, and knots of [Fe ii ] emission with dynamical times of <30 yr are found in the jets of the others. While only one jet is traced in H _2 , knots of H _2 and CO are detected in the jets of four protostars. H _2 is seen extending through the cavities, showing that they are filled by warm molecular gas. Bright H _2 emission is seen along the walls of a single cavity, while in three cavities narrow shells of H _2 emission are found, one of which has an [Fe ii ] knot at its apex. These data show cavities containing collimated jets traced in atomic/ionic gas surrounded by warm molecular gas in a wide-angle wind and/or gas accelerated by bow shocks in the jets.

Keywords

• Star formation
• Protostars
• Stellar jets
• Stellar winds
• Stellar accretion disks