JWST-ALMA study of a hub-filament system in the nascent phase

Abstract

Star clusters, including high-mass stars, form within hub-filament systems (HFSs). Observations of HFSs that remain unaffected by feedback from embedded stars are rare yet crucial for understanding the mass inflow process in high-mass star formation. Using the JWST NIRCAM images, Dewangan et al. 2024, reported that the high-mass protostar G11P1 is embedded in a candidate HFS (G11P1-HFS; <0.6 pc). Utilizing ALMA N2H+(1-0) data, we confirm the presence of G11P1-HFS and study the dense gas kinematics. We analyzed the position-position-velocity (PPV) map and estimated on-sky velocity gradient (Vg) and gravity (Fg) vectors. The spatial distribution of gas velocity and H2 column density was examined. The steep Vg of 5 km s−1 pc−1 and −7 km s−1 pc−1 toward either side of G11P1-hub, and the decreasing Vg toward the hub, identify G11P1-HFS as a small-scale HFS in its nascent phase. Vg and Fg align along the filaments, indicating gravity-driven flows. This work highlights the wiggled, funnel-shaped morphology of a HFS in PPV space, suggesting the importance of subfilaments or transverse gas flows in mass transportation to the hub.