학술논문
Discovery of a collimated jet from the low luminosity protostar IRAS 16253$-$2429 in a quiescent accretion phase with the JWST
Document Type
Working Paper
Author
Narang, Mayank; P., Manoj; Tyagi, Himanshu; Watson, Dan M.; Megeath, S. Thomas; Federman, Samuel; Rubinstein, Adam E.; Gutermuth, Robert; Garatti, Alessio Caratti o; Beuther, Henrik; Bourke, Tyler L.; Van Dishoeck, Ewine F.; Evans II, Neal J.; Anglada, Guillem; Osorio, Mayra; Stanke, Thomas; Muzerolle, James; Looney, Leslie W.; Yang, Yao-Lun; Tobin, John J.; Klaassen, Pamela; Karnath, Nicole; Atnagulov, Prabhani; Brunken, Nashanty; Fischer, William J.; Furlan, Elise; Green, Joel; Habel, Nolan; Hartmann, Lee; Linz, Hendrik; Nazari, Pooneh; Pokhrel, Riwaj; Rahatgaonkar, Rohan; Rocha, Will R. M.; Sheehan, Patrick; Slavicinska, Katerina; Stutz, Amelia; Tychoniec, Lukasz; Wolk, Scott
Source
Subject
Language
Abstract
Investigating Protostellar Accretion (IPA) is a JWST Cycle~1 GO program that uses NIRSpec IFU and MIRI MRS to obtain 2.9--28~$\mu$m spectral cubes of young, deeply embedded protostars with luminosities of 0.2 to 10,000~L$_{\odot}$ and central masses of 0.15 to 12~M$_{\odot}$. 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_\mathrm{bol}$ = 0.2 $L_\odot$) in the IPA program. The collimated jet is detected in multiple [Fe~II] lines, [Ne~II], [Ni~II], and H~I lines, but not in molecular emission. The atomic jet has a velocity of about 169~$\pm$~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~$\pm$~0.5\arcdeg. 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$\times10^{3}$~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 $0.4 -1.1\times10^{-10}~M_{\odot}$~yr~$^{-1}$.} The low mass loss rate is consistent with simultaneous measurements of low mass accretion rate ($2.4~\pm~0.8~\times~10^{-9}~M_{\odot}$~yr$^{-1}$) for IRAS~16253$-$2429 from JWST observations (Watson et al. in prep), 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.
Comment: Accepted to ApJL. Comments and feedback welcome
Comment: Accepted to ApJL. Comments and feedback welcome