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

Abstract

Context. 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, a recent study reported that the high-mass protostar G11P1 is embedded in a candidate HFS (G11P1-HFS; < 0.6 pc).

Aims. Utilizing ALMA N2H+(1–0) data, we confirm the presence of G11P1-HFS and study the dense gas kinematics.

Methods. We analyzed the position–position–velocity (PPV) map and estimated on-sky velocity gradient (Vg) and gravity (ℱg) vectors. We examined the spatial distribution of the gas velocity and the H2 column density.

Results. A steep Vg of 5 km s−1 pc−1 and −7 km s−1 pc−1 toward either side of G11P1-hub and a decreasing Vg toward the hub identify G11P1-HFS as a small-scale HFS in its nascent phase. Additionally, the Vg and ℱg align along the filaments, indicating gravity-driven flows.

Conclusions. This work highlights the wiggled funnel-shaped morphology of an HFS in PPV space and suggests the importance of sub-filaments or transverse gas flows in mass transportation to the hub.