Speaker
Description
Cosmic rays (CRs) remain a key uncertainty in galaxy evolution due to their poorly constrained transport and acceleration in diverse plasma environments. They may play a crucial role in shaping the multiphase structure of the Circumgalactic Medium (CGM), with their impact varying across different phases depending on their transport properties and coupling with the thermal plasma. A central question is how CRs might affect different CGM phases and whether CR pressure support may be dynamically significant. In this talk, I will discuss the influence of CRs on both the cold and hot phases of the CGM. I will present results from a suite of idealized simulations of a Milky Way-type host galaxy with varying satellite distributions, incorporating CRs from supernovae into both the host and satellite galaxies. I find that CR pressure enhances the surface area of ram pressure-stripped cool satellite clouds, boosting cooling in turbulent mixing layers and thereby prolonging cloud survival and increasing the cold-phase covering fraction. Conversely, I find that the CRs cannot efficiently heat gas to super-virial temperatures. I will also present results from new simulations exploring the dynamics of CR-driven shells and super-bubbles on a variety of scales in and around star-forming galaxies. Overall, these findings highlight the potential importance of CRs on galaxy ecosystems and how uncertainties in CR transport properties map to uncertainties in their importance.
| Collaboration(s) | Todd Thompson, Stephanie Tonnesen, Kung-Yi Su |
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