Meso-Scale Jets Expose Limits of Simplified Galaxy Evolution Models
Preprint simulations reveal jet-CCA coupling at meso-scales drives variable SMBH feeding, exposing gaps in large-volume galaxy models.
This 2026 arXiv preprint (v1, not peer-reviewed) presents hydrodynamical simulations of jet-regulated chaotic cold accretion (CCA) in a typical galaxy-group atmosphere, varying only turbulent driving strength across two runs. The work tracks accretion histories, phase-separated mass fluxes, power spectra, and C-ratio profiles, showing that both setups transition from Bondi-like to super-Bondi accretion once precipitation begins, yet remain mechanically dominated at low Eddington ratios. The strongly stirred case exhibits an early stormy phase with bursty feeding and fountain-like recycling, later shifting to a cloudy phase where central sink coupling weakens; the calmer run sustains a compact rainy state with inner-kpc recycling. Jet excavation suppresses condensation inside the cone while C~1 conditions persist at the jet-ambient interface. This meso-scale focus challenges cosmological simulations that rely on sub-grid prescriptions, as transport—not merely cold-gas production—controls feeding. Limitations include idealized initial conditions without full cosmological context or magnetic fields, and restriction to two turbulence variants rather than a statistical ensemble. Related work by Gaspari et al. (MNRAS 2013) established the CCA framework from X-ray and optical data, while recent EAGLE/TNG analyses (Schaye et al. 2023) highlight how unresolved meso-scale physics leads to over-quenched galaxies, underscoring the need for the BlackHoleWeather diagnostics.
HELIX: Jet-regulated CCA at meso-scales shows galaxy evolution hinges on unresolved transport physics, forcing cosmological codes to adopt finer sub-grid treatments or risk inaccurate quenching predictions.
Sources (3)
- [1]Primary Source(https://arxiv.org/abs/2605.27511)
- [2]Related Source(https://arxiv.org/abs/1301.6011)
- [3]Related Source(https://ui.adsabs.harvard.edu/abs/2023MNRAS.526.4978S)