Probing the Physical and Chemical Characteristics of an Extremely Early Class 0 Protostar in G204.4-11.3A2-NE
Year: 2025
Type: article
Abstract: We have observed the low-mass molecular cloud core G204.4-11.3A2-NE (G204NE) in the direction of Orion B giant molecular cloud with the Atacama Large Millimeter/submillimeter Array in Band 6. The 1.3 mm continuum images and visibilities unveil a compact central structure with a radius of ∼12 au, while showing no signature of binarity down to 18 au. The bolometric temperature and luminosity of this source are derived to be ∼33 K and ∼1.15 L ⊙ , respectively. Chemical stratification is observed in dense gas tracers, with C 18 O emission peaking at the continuum position surrounded by the spatially extended emission of N 2 D + and DCO + . This implies that the core is in a very early evolutionary stage in which CO depletion occurs in most regions except for a small area heated by the central source. The envelope kinematics indicate a rotating and infalling structure with a central protostar mass of 0.08–0.1 M ⊙ . The protostar drives a collimated outflow traced by CO, SiO, SO, and H 2 CO, with misaligned blueshifted and redshifted lobes exhibiting a pair of bow-like patterns. High-velocity jets, extending up to 720 au, are detected in CO, SiO, and SO lines. The jet launching region is likely within twice of the dust sublimation zone. The absence of a binary signature suggests the outflows and jets are driven by a single protostar, although a close binary cannot be ruled out. The observed deflection of the outflows and jet is likely due to turbulent accretion in a moderately magnetized core.
Source: The Astrophysical Journal
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
OpenAlex ID: W4417488564