Using the circumgalactic medium of dwarf galaxies as a calorimetric dark matter detector

Many popular non-standard models of dark matter (DM) can inject heat into the surrounding baryonic medium (e.g., dark photon DM, axion-like particles, sterile neutrinos, primordial compact objects and others). We implement a simple scheme to inject heat due to dark matter decay in the RAMSES hydrodynamic simulation. We then simulate an isolated gas-rich dwarf similar to the WLM galaxy, and show that the extra DM heating leads to an increase in temperature of the circumgalactic medium (CGM) of the galaxy. This leads to a substantial impact on the HI and metal ion column densities of the dwarf, and we thus show how column density measurements of the CGM of field dwarfs can used to probe non-standard models of dark matter.