Uncovering the Hidden Physical Structures and Protostellar Activities in the Low-metallicity S284-RE Region: Results from ALMA and JWST
Source
Astrophysical Journal
ISSN
0004637X
Date Issued
2025-02-10
Author(s)
Jadhav, O. R.
Dewangan, L. K.
Verma, Aayushi
Bhadari, N. K.
Maity, A. K.
Sharma, Saurabh
Mamta,
Abstract
We present an observational study of the S284-RE region, a low-metallicity area associated with the extended S284 H ii region. A thermally supercritical filament (mass ∼2402 M<inf>⊙</inf> and length ∼8.5 pc) is investigated using the Herschel column density map. The Spitzer ratio 4.5 μm/3.6 μm map traces the H<inf>2</inf> outflows in this filament, where previously reported young stellar objects (YSOs) are spatially distributed. Analysis of the YSO distribution has revealed three active star-forming clusters (YCl1, YCl2, and YCl3) within the filament. YCl3 seems to be the most evolved and YCl2 the youngest, while YCl1 displays signs of nonthermal fragmentation. The JWST (F470N+F444W)/F356W ratio map reveals at least seven bipolar H<inf>2</inf> outflows, with four (olc1-olc4) in YCl1 and three (ol1-ol3) in YCl2. The driving sources of these outflows are identified based on outflow geometry, Atacama Large Millimeter/submillimeter Array (ALMA) continuum peaks, and YSO positions. Two ALMA continuum sources—#2 and #3—from the M-R<inf>eff</inf> plot are recognized as potential massive star formation candidates. ALMA continuum source #2 hosts at least three outflow-driving sources, whereas ALMA continuum source #3 contains two. The bipolar outflow olc1, driven by an embedded object within continuum source #2, is likely a massive protostar, as indicated by the Br-α and PAH emissions depicted in the JWST (F405N+F444W)/F356W ratio map. The presence of H<inf>2</inf> knots in the outflows olc1 and ol1 suggests episodic accretion. Overall, the study investigates a massive protostar candidate, driving the ∼2.7 pc H<inf>2</inf> outflow olc1 and undergoing episodic accretion.
