The launching of cosmic ray-driven outflows

Cosmic rays (CRs) are thought to be an important feedback mechanism in star-forming galaxies. They can provide source of pressure support and possibly drive outflows. We perform multidimensional CR-magnetohydrodynamic simulations including transport by streaming diffusion investigate wind launching from initially hydrostatic atmosphere CRs. estimate a characteristic Eddington limit on the CR flux for which force exceeds gravity compare it simulated systems. Scaling our results conditions galaxies, we find that CRs likely contribute driving outflows broad range star formation environments. quantify momentum energy transfer between gas, along with associated mass outflow rates under different assumptions about relative importance transport. In streaming, observe growth saturation acoustic instability, but gas remain well coupled, transferred efficiently even when this instability is present. Higher fluxes transferr more stronger When present, most takes form Alfv\'{e}n wave heating raising its internal energy, lower fractional contribution kinetic outflow. also consider runs radiative cooling, modifies temperature profiles does not seem have large impact super-Eddington fluxes.