IC 5146 Dark Streamer: The First Reliable Candidate of Edge Collapse, Hub-filament Systems, and Intertwined Sub-filaments

The paper presents an analysis of multi-wavelength data a nearby star-forming site IC 5146 dark Streamer (d $\sim$600 pc), which has been treated as single and long filament, fl. Two hub-filament systems (HFSs) are known toward the eastern western ends Earlier published results favor simultaneous evidence HFSs end-dominated collapse (EDC) in Herschel column density map (resolution $\sim$13$''$.5) reveals two intertwined sub-filaments (i.e., fl-A fl-B) fl, displaying nearly double helix-like structure. This picture is also supported by C$^{18}$O(3-2) emission. scenario "fray fragment" may explain origin sub-filaments. In direction cloud components around 2 4 km s$^{-1}$ depicted using $^{13}$CO(1-0) C$^{18}$O(1-0) emission, connected velocity space. spatially found at overlapping areas these can be explained cloud-cloud collision scenario. Non-thermal gas motion fl with larger Mach number found. magnetic field position angle measured from filament's axis shows linear trend along filament. signature confirmed other EDC filaments, presenting more quantitative confirmation Based on our observational outcomes, we witness multiple processes operational Streamer. Overall, recognized first reliable candidate edge collapse, HFSs, together.