The emergence of Hub-Filament Systems

In Hacar et al 2023, our team demonstrate that filaments follow a specific L ~ M0.5 relationship in the Mass-Length (M-L) phase space characteristic of the hierarchical structure of the ISM.  In comparison, Hub-Filament- Systems (HFS) populate different region in the M-L phase space, showing higher masses for similar sizes than their parental filaments. As primary goal of the EMERGE project, we aim to investigate the origin of HFS as precursors of clusters and high-mass stars in our Galaxy.

In Hacar et al (2025) (Paper V), we combined previous scaling relations with new analytic calculations and created a toy model to explore the different physical regimes described by the M-L diagram. Despite its simplicity, our model accurately reproduces several observational properties reported for filaments and HFS such as their expected typical aspect ratio, mean surface density, and gas accretion rate. Moreover, this model naturally explains the different mass and length regimes populated by filaments and HFS, respectively. Results. Our model predicts a dichotomy between filamentary (A ≥3) and spheroidal (A <3) structures connected to the relative importance of their fragmentation, accretion, and collapse timescales. Individual filaments with low accretion rates are dominated by an efficient internal fragmentation. In contrast, and favored by the high accretion rates created at the intersection of filaments, the formation of compact HFS triggers a geometric phase-transition leading to the gravitational collapse of these structures at parsec- scales in <1 Myr.

Data Products

• Access to DR1 in Dataverse (link)