The Impact of Cosmic Ray Injection on Magnetic Flux Tubes in a Galactic Disk

Abstract In a seminal paper, Parker showed the vertical stratification of interstellar medium (ISM) is unstable if magnetic fields and cosmic rays provide too large fraction pressure support. Cosmic ray acceleration linked to star formation, so Parker’s instability its nonlinear outcomes are type formation feedback. Numerical simulations have shown can significantly restructure ISM, thinning thermal gas layer thickening field layer. However, timescale on which this occurs rather long (∼0.4 Gyr). Furthermore, conditions for depend model adopted transport. work, we connect feedback problems by examining effect single, spatially temporally localized injection ISM over ∼1 kpc 3 scales. We perform magnetohydrodynamic using Athena++ code, varying background properties, dominant transport mechanism, characteristics between our simulation runs. find robust effects buoyancy all models, with disruption timescales as short 100 Myr when equilibrium dominated pressure.