Interstellar Complex Organic Molecules and Molecular Outflows in NGC 1333 IRAS 4B and 4B' Observed Using NOEMA

Abstract

We present interferometric observations with the Northern Extended Millimeter Array (NOEMA) of NGC 1333 IRAS 4B and 4B', two young stellar objects (YSOs) within the Perseus molecular cloud. YSOs, especially Class 0 protostars, are rich in gas-phase interstellar complex organic molecules (iCOMs), but relatively little is known about the spatial distribution of these important prebiotic molecules. Various molecules were imaged within IRAS 4B and the surrounding area in the 145 GHz spectral range, revealing hundreds of molecular transitions within the warm inner envelope of IRAS 4B. This work provides derived physical parameters (rotational temperature, column density, velocity shift with respect to local standard of rest, and full-width at half-maximum spectral line width) for 11 molecules toward IRAS 4B including methanol (CH$_3$OH and isotopologues), methyl formate (HCOOCH$_3$), dimethyl ether (CH$_3$OCH$_3$), acetaldehyde (CH$_3$CHO), ethanol (C$_2$H$_5$OH), glycolaldehyde (CH$_2$OHCHO), acetone (CH$_3$COCH$_3$), and isocyanic acid (HNCO). Out of these molecules, 10 are iCOMs (excluding HNCO) that trace the inner envelope of IRAS 4B and mark it as a rich source of organic material. There is a strong spatial correlation between the continuum emission of IRAS 4B and iCOM molecular emission and among various iCOMs with each other. Physical parameter and integrated intensity maps show that IRAS 4B is a binary protostar system that drives a jet in a north-south orientation and an outflow in a northwest-southeast orientation. IRAS 4B' also drives a west-east outflow but shows no evidence of molecular emission cospatial with its continuum emission.