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JWST Observes Highly Collimated Atomic Jet from a Dim Protostar

In a new study made possible by the James Webb Space Telescope (JWST), astronomers have unveiled a highly collimated atomic jet emanating from IRAS 16253−2429, a Class 0 protostar and the dimmest object within the Investigating Protostellar Accretion (IPA) program. This young, deeply embedded star, which has a luminosity of just 0.2 solar masses and…

February 8, 2024

In a new study made possible by the James Webb Space Telescope (JWST), astronomers have unveiled a highly collimated atomic jet emanating from IRAS 16253−2429, a Class 0 protostar and the dimmest object within the Investigating Protostellar Accretion (IPA) program. This young, deeply embedded star, which has a luminosity of just 0.2 solar masses and lies within the Ophiuchus molecular cloud, showcases an exceptional example of stellar phenomena even at its low brightness level.

The IPA program, a medium GO initiative in JWST Cycle 1, leverages the NIRSpec integral field units and MIRI Medium Resolution Spectrograph to explore the accretion processes across a spectrum of protostellar masses, aiming to shed light on the complex mechanisms driving star formation. The detected jet from IRAS 16253−2429, observable in multiple spectral lines, speeds through space at approximately 169 km/s, displaying increasing width from its origin point and indicating a quiescent phase of accretion for the protostar.

A zoomed-in view of the NIRSpec and MIRI channel 1 short (A) field with the red representing continuum emission at 4.17 μm, the green showing H2 0-0 S(11) at 4.18 μm, and the blue depicting [Fe ii] at 5.34 μm. A local continuum has been subtracted to make the line maps. Source: Narang et al

This discovery not only highlights the capability of very low-mass protostars to generate such dynamic and collimated jets but also contributes significantly to our understanding of star formation. Jets and outflows are crucial in removing angular momentum from accreting material, thereby facilitating the growth of the central star. The detailed analysis of the jet’s properties, including its mass-loss rate, complements existing theories on the origins and impacts of protostellar jets and outflows, particularly in shaping the initial mass function and influencing star formation efficiency through energy and momentum transfer to the surrounding medium.

The findings from IRAS 16253−2429, enriched by the unparalleled sensitivity and resolution of the JWST, offer invaluable insights into the early stages of stellar development, challenging existing models and opening new avenues for research into the physics of star formation and the role of accretion-driven jets in this fundamental astronomical process.

Source: Narang, Mayank, et al. “Discovery of a Collimated Jet from the Lowluminosity Protostar IRAS 16253−2429 in a Quiescent Accretion Phase with the JWST.” The Astrophysical Journal Letters, vol. 962, no. 1, 2024, p. L16, dx.doi.org/10.3847/20418213/ad1de3, https://doi.org/10.3847/20418213/ad1de3.

Featured Image: HH46/HH47, ESA/Hubble & NASA, B. Nisini