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Cluster spiral galaxies suffer catastrophic losses of the cool, neutral gas component of their interstellar medium due to ram pressure stripping, contributing to the observed quenching of star formation in the disc compared to galaxies in lower density environments. However, the short-term effects of ram pressure on the star formation rate and active galactic nucleus (AGN) activity of galaxies undergoing stripping remain unclear. Numerical studies have recently demonstrated cosmic rays can dramatically influence galaxy evolution for isolated galaxies, yet their influence on ram pressure stripping remains poorly constrained. We perform the first cosmic ray magnetohydrodynamic simulations of an L* galaxy undergoing ram pressure stripping, including radiative cooling, self-gravity of the gas, star formation, and stellar feedback. We find the microscopic transport of cosmic rays plays a key role in modulating the star formation enhancement experienced by spirals at the outskirts of clusters compared to isolated spirals. Moreover, we find that galaxies undergoing ram pressure stripping exhibit enhanced gas accretion on to their centres, which may explain the prevalence of AGNs in these objects. In agreement with observations, we find cosmic rays significantly boost the global radio emission of cluster spirals. Although the gas removal rate is relatively insensitive to cosmic ray physics, we find that cosmic rays significantly modify the phase distribution of the remaining gas disc. These results suggest observations of galaxies undergoing ram pressure stripping may place novel constraints on cosmic ray calorimetry and transport.

Much progress has been made recently in the acceleration of ∼104 K clouds to explain absorption line measurements of the circumgalactic medium and the warm, atomic phase of galactic winds. However, the origin of the cold, molecular phase in galactic winds has received relatively little theoretical attention. Studies of the survival of ∼104 K clouds suggest efficient radiative cooling may enable the survival of expelled material from galactic discs. Alternatively, gas colder than 104 K may form within the outflow, including molecules if dust survives the acceleration process. We explore the survival of dusty clouds in a hot wind with three-dimensional hydrodynamic simulations including radiative cooling and dust modelled as tracer particles. We find that cold ∼103 K gas can be destroyed, survive, or transformed entirely to ${\sim}10^4\,$ K gas. We establish analytic criteria distinguishing these three outcomes that compare characteristic cooling times to the system’s ‘cloud crushing’ time. In contrast to typically studied ∼104 K clouds, colder clouds are entrained faster than the drag time as a result of efficient mixing. We find that while dust can in principle survive embedded in the accelerated clouds, the survival fraction depends critically on the time dust spends in the hot phase and on the effective threshold temperature for destruction. We discuss our results in the context of polluting the circumgalactic medium with dust and metals, as well as understanding observations suggesting rapid acceleration of molecular galactic winds and ram-pressure-stripped tails of jellyfish galaxies.