Discovery of a Collimated Jet from the Low-luminosity Protostar IRAS 16253‑2429 in a Quiescent Accretion Phase with the JWST

February 2024 • 2024ApJ...962L..16N

Authors • Narang, Mayank • Manoj, P. • Tyagi, Himanshu • Watson, Dan M. • Megeath, S. Thomas • Federman, Samuel • Rubinstein, Adam E. • Gutermuth, Robert • Caratti o Garatti, Alessio • Beuther, Henrik • Bourke, Tyler L. • Van Dishoeck, Ewine F. • Evans, Neal J. • Anglada, Guillem • Osorio, Mayra • Stanke, Thomas • Muzerolle, James • Looney, Leslie W. • Yang, Yao-Lun • Klaassen, Pamela • Karnath, Nicole • Atnagulov, Prabhani • Brunken, Nashanty • Fischer, William J. • Furlan, Elise • Green, Joel • Habel, Nolan • Hartmann, Lee • Linz, Hendrik • Nazari, Pooneh • Pokhrel, Riwaj • Rahatgaonkar, Rohan • Rocha, Will R. M. • Sheehan, Patrick • Slavicinska, Katerina • Stutz, Amelia M. • Tobin, John J. • Tychoniec, Lukasz • Wolk, Scott

Abstract • Investigating Protostellar Accretion (IPA) is a JWST Cycle 1 GO program that uses NIRSpec integral field units and MIRI Medium Resolution Spectrograph to obtain 2.9–28 μm spectral cubes of young, deeply embedded protostars with luminosities of 0.2–10,000 L _⊙ and central masses of 0.15–12 M _⊙. In this Letter, we report the discovery of a highly collimated atomic jet from the Class 0 protostar IRAS 16253‑2429, the lowest-luminosity source (L _bol = 0.2 L _⊙) in the IPA program. The collimated jet is detected in multiple [Fe II] lines and [Ne II], [Ni II], and H I lines but not in molecular emission. The atomic jet has a velocity of about 169 ± 15 km s^‑1, after correcting for inclination. The width of the jet increases with distance from the central protostar from 23 to 60 au, corresponding to an opening angle of 2.°6 ± 0.°5. By comparing the measured flux ratios of various fine-structure lines to those predicted by simple shock models, we derive a shock speed of 54 km s^‑1 and a preshock density of 2.0 × 10³ cm^‑3 at the base of the jet. From these quantities and using a suite of jet models and extinction laws, we compute a mass-loss rate between 0.4 and 1.1 ×10^‑10 M _⊙ yr ^‑1. The low mass-loss rate is consistent with simultaneous measurements of low mass accretion rate (2.4 ± 0.8 × 10^‑9 M _⊙ yr^‑1) for IRAS 16253‑2429 from JWST observations, indicating that the protostar is in a quiescent accretion phase. Our results demonstrate that very low-mass protostars can drive highly collimated, atomic jets, even during the quiescent phase.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2024ApJ...962L..16N
• PDF https://iopscience.iop.org/article/10.3847/2041-8213/ad1de3/pdf
• PREPRINT http://arxiv.org/abs/2310.14061
• DATA https://archive.stsci.edu/mastbibref.php?bibcode=2024ApJ...962L..16N
• DATA https://doi.org/10.17909/3kky-t040
• DATA https://irsa.ipac.caltech.edu/bibdata/2024/N/2024ApJ...962L..16N.html
• ELECTR https://doi.org/10.3847/2041-8213/ad1de3