Efficient cosmic-ray transport in CR-pressure-dominated CGM simulations produces stronger cool-gas absorption (MgII, SiII) and covering fractions matching star-forming galaxies, while slow transport underproduces them.
Cosmic Ray-Driven Galactic Winds with Resolved ISM and Ion-Neutral Damping
3 Pith papers cite this work. Polarity classification is still indexing.
abstract
Feedback processes in galaxies dictate their structure and evolution. Baryons can be cycled through stars, which inject energy into the interstellar medium (ISM) in supernova explosions, fueling multiphase galactic winds. Cosmic rays (CRs) accelerated at supernova remnants are an important component of feedback. CRs can effectively contribute to wind driving; however, their impact heavily depends on the assumed CR transport model. We run high-resolution "tallbox" simulations of a patch of a galactic disk using the moving mesh magnetohydrodynamics code AREPO, including varied CR implementations and the CRISP non-equilibrium thermochemistry model. We characterize the impact of CR feedback on star formation and multiphase outflows. While CR-driven winds are able to supply energy to a global-scale wind, a purely thermal wind loses most of its energy by the time it reaches 3 kpc above the disk midplane. We further find that the adopted CR transport model significantly affects the steady-state of the wind. In the model with CR advection, streaming, diffusion, and nonlinear Landau damping, CRs provide very strong feedback. Additionally accounting for ion-neutral damping (IND) decouples CRs from the cold ISM, which reduces the impact of CRs on the star formation rate. Nevertheless, CRs in this most realistic model are able to accelerate warm gas and levitate cool gas in the wind but have little effect on cold gas and hot gas. This model displays moderate mass loading and significant CR energy loading, demonstrating that IND does not prevent CRs from providing effective feedback.
representative citing papers
Ancient cosmic ray halos from the central galaxy boost Perseus's cool core via inverse-Compton scattering, simultaneously explaining radio minihalo, giant halo, X-ray properties, and gamma-ray data without re-acceleration.
A review summarizing pitfalls in older CR-MHD models and progress toward more rigorous treatments that connect microphysical CR scales to galactic dynamics.
citing papers explorer
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CRexit observed: probing cosmic ray transport in the circumgalactic medium with absorption line spectra
Efficient cosmic-ray transport in CR-pressure-dominated CGM simulations produces stronger cool-gas absorption (MgII, SiII) and covering fractions matching star-forming galaxies, while slow transport underproduces them.
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An Inverse-Compton-Boosted Cool Core Unifies Perseus's Radio and X-ray Halos
Ancient cosmic ray halos from the central galaxy boost Perseus's cool core via inverse-Compton scattering, simultaneously explaining radio minihalo, giant halo, X-ray properties, and gamma-ray data without re-acceleration.
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Cosmic Rays on Galaxy Scales: Progress and Pitfalls for CR-MHD Dynamical Models
A review summarizing pitfalls in older CR-MHD models and progress toward more rigorous treatments that connect microphysical CR scales to galactic dynamics.