Discovery of a Compact Hub-Filament System in G286.21+0.17 with JWST and ALMA: Insights into Protocluster Formation and Competitive Accretion
Abstract
We present a multi-wavelength study of the massive protocluster G286.21+0.17 (G286) using \emph{JWST} near-infrared (NIR) imaging and ALMA H13CO+(1--0) observations. The \emph{JWST} images uncover a compact (∼0.5 pc) hub-filament system (HFS), comprising a dense central hub connected by at least four converging filaments seen in absorption, along with multiple H2 protostellar jets/outflows. The hub hosts the dense core G286c1. H13CO+ emission confirms this HFS over [−19.2, −16.4]~km~s−1, while the \emph{JWST} images also trace prominent photodissociation regions surrounding H\,{\sc ii}~region~A, powered by a B-type star. The identified H13CO+ skeletons closely trace the major \emph{JWST} absorption structures and show steep velocity gradients indicative of inflow. The radial distribution of ALMA 1.3 mm continuum cores (ALMAGAL and Cheng et al. 2020) exhibits power-law trends toward the hub center. The core number density, surface density, and core mass follow Y ∝ rα with αρ ∼−2.8 to −1.1, αΣ ∼−0.4 to −0.6, and αM ∼−0.7, whereas the core diameter remains nearly constant. Together with filament mass accretion rates of 7.6--11×10−5 M⊙ yr−1, these results are consistent with competitive accretion, highlighting preferential core growth toward the hub. Increasing filament linewidths toward the hub imply gravity-driven inflow, but misaligned local velocity gradient and gravitational force directions along filaments point to a dynamically evolved system. The HFS likely formed through large-scale gas-layer interactions aided by compression from the adjacent H\,{\sc ii} region. Overall, star formation in G286 appears to be regulated by filamentary accretion, competitive core growth in the hub, and stellar feedback.
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BibTeX
@misc{dewangan2026discovery,
title = {{Discovery of a Compact Hub-Filament System in G286.21+0.17 with JWST and ALMA: Insights into Protocluster Formation and Competitive Accretion}},
author = {L. K. Dewangan and N. K. Bhadari and Ram K. Yadav and A. K. Maity and O. R. Jadhav and Kee-Tae Kim and Paul F. Goldsmith and A. Saha and Dana Alina and Chang Won Lee and Saurabh Sharma and Tie Liu and Patricio Sanhueza and Tapas Baug and E. Sharma and Fengwei Xu and Ariful Hoque and James O. Chibueze and Dana Makarova and Wenyu Jiao},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2605.14693},
eprint = {2605.14693},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.14693},
}
RIS
TY - UNPB
TI - Discovery of a Compact Hub-Filament System in G286.21+0.17 with JWST and ALMA: Insights into Protocluster Formation and Competitive Accretion
AU - L. K. Dewangan
AU - N. K. Bhadari
AU - Ram K. Yadav
AU - A. K. Maity
AU - O. R. Jadhav
AU - Kee-Tae Kim
AU - Paul F. Goldsmith
AU - A. Saha
AU - Dana Alina
AU - Chang Won Lee
AU - Saurabh Sharma
AU - Tie Liu
AU - Patricio Sanhueza
AU - Tapas Baug
AU - E. Sharma
AU - Fengwei Xu
AU - Ariful Hoque
AU - James O. Chibueze
AU - Dana Makarova
AU - Wenyu Jiao
PY - 2026
DA - 2026/09/15
PB - arXiv
DO - 10.48550/arxiv.2605.14693
UR - https://arxiv.org/abs/2605.14693
AB - We present a multi-wavelength study of the massive protocluster G286.21+0.17 (G286) using \emph{JWST} near-infrared (NIR) imaging and ALMA H^13CO^+(1--0) observations. The \emph{JWST} images uncover a compact (∼0.5 pc) hub-filament system (HFS), comprising a dense central hub connected by at least four converging filaments seen in absorption, along with multiple H_2 protostellar jets/outflows. The hub hosts the dense core G286c1. H^13CO^+ emission confirms this HFS over [−19.2, −16.4]~km~s^−1, while the \emph{JWST} images also trace prominent photodissociation regions surrounding H\,{\sc ii}~region~A, powered by a B-type star. The identified H^13CO^+ skeletons closely trace the major \emph{JWST} absorption structures and show steep velocity gradients indicative of inflow. The radial distribution of ALMA 1.3 mm continuum cores (ALMAGAL and Cheng et al. 2020) exhibits power-law trends toward the hub center. The core number density, surface density, and core mass follow Y ∝ r^α with α_ρ ∼−2.8 to −1.1, α_Σ ∼−0.4 to −0.6, and α_M ∼−0.7, whereas the core diameter remains nearly constant. Together with filament mass accretion rates of 7.6--11×10^−5 M_⊙ yr^−1, these results are consistent with competitive accretion, highlighting preferential core growth toward the hub. Increasing filament linewidths toward the hub imply gravity-driven inflow, but misaligned local velocity gradient and gravitational force directions along filaments point to a dynamically evolved system. The HFS likely formed through large-scale gas-layer interactions aided by compression from the adjacent H\,{\sc ii} region. Overall, star formation in G286 appears to be regulated by filamentary accretion, competitive core growth in the hub, and stellar feedback.
ER -