Study finds stellar mass distribution may be encoded in molecular cloud filament structure
Researchers analyzing seven nearby molecular clouds found that the distribution of filament densities across different spatial scales matches the Salpeter stellar initial mass function, a fundamental pattern in star formation first identified in 1955. The filament linear density function steepens from small to large scales but produces a composite slope nearly identical to the Salpeter value across all clouds studied. This suggests the universal stellar mass spectrum may originate from the hierarchical structure of cold interstellar material rather than from processes during star formation itself.
Using a multiscale extraction method called getsf, astronomers measured the filament linear density function (FLDF) across seven nearby molecular clouds ranging from 140 to 920 parsecs away. They found that when filament densities are measured at different spatial scales, the slopes vary systematically—shallow at small scales and steeper at larger scales. However, when integrated across all scales, the composite distribution follows a power law with a slope of approximately 1.30–1.34, matching the Salpeter slope of 1.35 that describes the distribution of stellar masses. Remarkably, this composite slope remained consistent across all seven clouds despite significant variations in their physical properties, including a tenfold difference in the fraction of supercritical filaments. The findings suggest that the nearly universal stellar mass function observed across diverse star-forming environments may be a direct consequence of how gas is hierarchically organized in molecular clouds.
What's missing
The study does not discuss potential mechanisms by which filament hierarchies might be disrupted or modified during the star formation process itself, nor does it address whether the observed filament structure is sufficient to fully explain stellar mass distributions or whether additional physical processes during gravitational collapse play a role.
What different sources said
- arXiv astro-phCenter
From inter-filamentary gas to filaments and hubs: gas flows in the Mon R2 hub-filament system
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