The Outflow of the B335 Protostar. II. After the Outburst
September 2026 • 2026ApJ..1008...64H
Abstract • The Barnard 335 (B335) protostar has recently undergone a major, still ongoing, outburst detected in scattered light from its outflow cavity, offering a rare opportunity to study its impact on a protostellar jet. We use James Webb Space Telescope (JWST) NIRCam photometry of background stars behind B335 from 2.7 to 4.4 μm to map extinction and H2O ice absorption, showing that the outflow has carved a cavity in the molecular core. We measure proper motions of shock fronts emerging from the protostar of 131--227 km s-1. The kinematic age of the most prominent shock front, 3E, corresponds to the early phase of the current outburst. JWST/NIRSpec Integral Field Unit data show that the youngest shock, 2E, exhibits ionic lines but no molecular emission. Shock 3E shows strong CO emission together with H2 and [Fe II], whereas older shocks show weaker CO and are dominated by H2 and [Fe II]. The feature 0E, closest to the protostar, appears to be a stationary shock. CO-line-removed spectra near the protostar show that the unsaturated absorption features of 13CO2, OCN--, and OCS increase strongly toward the source. The ice properties are otherwise similar to those along lower-extinction sight lines. In the central bipolar reflection nebula, CO gas is seen in scattered emission from the immediate protostellar surroundings, but a few arcseconds farther out, absorption by cooler CO gas in the outflow cavity is detected.
Links
- PDF https://iopscience.iop.org/article/10.3847/1538-4357/ae876f/pdf
- PREPRINT http://arxiv.org/abs/2602.12060
- DATA https://archive.stsci.edu/mastbibref.php?bibcode=2026ApJ..1008...64H
- DATA https://doi.org/10.17909/etar-9w74
- DATA https://doi.org/10.17909/z839-ka94
- ELECTR https://doi.org/10.3847/1538-4357/ae876f
