2024/11/21 by A. K. Maity, L. K. Dewangan, Maity, A. K. +13 · 1 citation
Physics and Astronomy · #Astrophysics of Galaxies (astro-ph.GA) #Black Holes and Theoretical Physics #FOS: Physical sciences #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2411.13870
openalex publication_date 2024/11/21 · openalex created_date 2024/11/24 · openalex updated_date 2026/07/28
Hub-filament systems (HFSs) are potential sites of massive star formation (MSF). To understand the role of filaments in MSF and the origin of HFSs, we conducted a multi-scale and multi-wavelength observational investigation of the molecular cloud G321.93-0.01. The 13CO(J = 2-1) data reveal multiple HFSs, namely, HFS-1, HFS-2, and a candidate HFS (C-HFS). HFS-1 and HFS-2 exhibit significant mass accretion rates (M|| > 10-3 M\odot yr-1) to their hubs (i.e., Hub-1 and Hub-2, respectively). Hub-1 is comparatively massive, having higher M|| than Hub-2, allowing to derive a relationship M|| ∝ Mβ_\rmhub, with β∼1.28. Detection of three compact HII regions within Hub-1 using MeerKAT 1.28 GHz radio continuum data and the presence of a clump (ATL-3), which meets Kauffmann & Pillai's criteria for MSF, confirm the massive star-forming activity in HFS-1. We find several low-mass ALMA cores (1-9 M\odot) inside ATL-3. The presence of a compact HII region at the hub of C-HFS confirms that it is active in MSF. Therefore, HFS-1 and C-HFS are in relatively evolved stages of MSF, where massive stars have begun ionizing their surroundings. Conversely, despite a high M||, the non-detection of radio continuum emission toward Hub-2 suggests it is in the relatively early stages of MSF. Analysis of 13CO(J = 2-1) data reveals that the formation of HFS-1 was likely triggered by the collision of a filamentary cloud about 1 Myr ago. In contrast, the relative velocities (\gtrsim 1 km s-1) among the filaments of HFS-2 and C-HFS indicate their formation through the merging of filaments.