Separate the turbulent states of cold and warm-hot filament gas

Characterize the turbulent state of the cold and warm-hot phases of diffuse cosmic-filament gas separately, including the role of cold accretion flows, to determine how these phases contribute to the overall turbulent cascade.

Background

The analysis deliberately treats the diffuse filament gas as a single population spanning cold photoionised and warm-hot phases, while removing collapsed and star-forming gas whose velocity and thermodynamic properties are not fully resolved. The authors explicitly defer disentangling the turbulence of the individual phases and the influence of cold accretion flows to future work within the WEFT programme.

References

We characterise this diffuse gas as a whole, disentangling the turbulent state of its cold and warm-hot phases, and the role of cold accretion flows, is left to future work in the WEFT programme.

— The WEFT project: I. The emergence of turbulence in a cosmic filament  (2609.17205 - Lebeau et al., 15 Sep 2026) in Section 2.2, “Selecting the diffuse filament gas”

Three questions follow and motivate the continuation of the WEFT programme. The first is the full multiscale structure of the cascade, the distribution of singularity strengths that a bifractal or lognormal description cannot capture, which we will address through a wavelet-based multifractal analysis.

— The WEFT project: I. The emergence of turbulence in a cosmic filament  (2609.17205 - Lebeau et al., 15 Sep 2026) in Section 8.3, “Limitations and perspectives”