2025-05-28 –, Main Conference Room
We exploit the unprecedented capabilities of JWST in the MIR, using the MIRI/MRS, performing a spatially-resolved study of the multi-phase ISM in the heart of the face-on spiral galaxy M83. Our detailed analysis probing the distribution of the multi-phase gas on spatial scales ~5 pc, is uncovering the effect recently-formed massive stars, observed with HST/COS, have on the reservoirs of gas and active star formation. We will report on the intriguing first detections of [Ne V] 14.3 micron and [Ne VI] 7.7 micron in this starburst region. We find that photoionization models of fast radiative shocks are able to reproduce the observed emission line fluxes only for the lowest preshock density available in the library. Additionally, comparison with tailored active galactic nuclei (AGN) photoionization models assuming a two-zone structure confirm that the observed high ionization fluxes are also compatible with emission expected from a cloud ionized by the radiation cone of an AGN. Previously known as a purely starburst system, these new findings on M83 demand a reassessment of its nature, and of objects similar to it, particularly now that we have access to the unparalleled infrared sensitivity and spatial resolution of JWST.
