CORINOS. I. JWST/MIRI Spectroscopy and Imaging of a Class 0 Protostar IRAS 15398–3359

Abstract The origin of complex organic molecules (COMs) in young Class 0 protostars has been one the major questions astrochemistry and star formation. While COMs are thought to form on icy dust grains via gas-grain chemistry, observational constraints their formation pathways have limited gas-phase detection. Sensitive mid-infrared spectroscopy with JWST enables unprecedented investigation COM by measuring ice absorption features. Mid-infrared emission from disks outflows provide complementary protostellar systems. We present an overview JWST/Mid-Infrared Instrument (MIRI) Medium Resolution Spectroscopy (MRS) imaging a protostar, IRAS 15398?3359, identify several solid-state features 4.9–28 ? m wavelength range. These can be attributed common species, such as H 2 O, CH 3 OH, NH , 4 may contributions more C 5 OH CHO. In addition features, MRS spectra show many weaker lines at 6–8 m, which due warm CO gas water vapor, possibly embedded disk previously unseen. Finally, we detect [Fe ii ], [Ne [S i tracing bipolar jet outflow cavities. MIRI serendipitously covers southwestern (blueshifted) lobe showing four shell-like structures similar traced molecular submillimeter wavelengths. This analysis highlights vast potential JWST/MIRI observations previews scientific discoveries coming years.