Investigating Protostellar Accretion Across the Mass Spectrum

We propose an Investigation of Protostellar Accretion (IPA) and accretion driven feedback using the NIRSPec and MIRI MRS IFUs. IPA will target 5 protostars with luminosities of 0.2 to 10,000 Lsun, stellar masses of 0.1 to 12 Msun, and distances of 150 pc to 1.6 kpc. Each shows a disk + outflow cavity morphology, is in its primary accretion phase, is deeply embedded, and requires observations at > 3 micron. Using JWSTs combination of sensitivity, angular resolution, and spectral resolution, IPA will observe each protostar in the 2.9-28 micron range and map ionic, atomic, molecular and continuum emission at spatial resolutions of 30 AU (for the lowest mass sources) to 300 AU (for the highest mass source). IPA will use spectroscopic signatures of disk accretion to measure the rate and mode of mass accretion, and measure how accretion scales with stellar mass. It will also observe shocks due to wide angle winds carving cavities into the protostellar envelopes, using the angular resolution of JWST to meassure mass flow and velocity along the cavities. The combination of accretion and wind data will show how the wind properties depend on accretion. Finally, IPA will look for the effect of radiative feedback from the most massive protostar, testing models of high mass star formation that require the release of radiation along outflow cavities. In total, IPA will observe in unprecedented detail the coupled accretion and feedback that plays a central role in determining the masses of stars, providing essential inputs for cloud scale simulations of star formation and the initial mass function, and setting the stage for future surveys with JWST to enlarge the sample.