Regulating the cooling in the galactic corona with different heating models in simulations of Milky Way-like galaxies

Star-forming galaxies like the Milky Way would exhaust their cold gas within a few billion years if it were not continuously replenished. The hot circumgalactic medium (CGM), or corona, surrounding these galaxies is the natural reservoir for this resupply, but in idealised simulations it cools too efficiently, driving star formation above observed levels. Some form of heating is thought to regulate this accretion, yet how it should be modelled, and how sensitive the hot CGM is to it, remains an open question. This thesis investigates how different heating prescriptions affect the corona of an isolated, Milky-Way-like galaxy and the gas exchange between corona and disc. Using the moving-mesh code AREPO with the SMUGGLE model for the ISM and stellar feedback, we evolve simulations sharing identical initial conditions and differing only in the coronal heating: a baseline (No-Heat), two prescriptions compensating radiative losses on different timescales (Heat 1 and Heat 2), and a radio-mode AGN model injecting energy through discrete bubbles, with the budget set from the halo X-ray luminosity via a luminosity–temperature relation (NF model). The runs are compared at matched times through several complementary diagnostics: the gas mass per phase, the coronal profiles, the star formation history, and the disc flows. In all models the corona eventually cools and feeds the disc, differing mainly in how each prescription slows this process. Heat 2 affects the innermost corona, Heat 1 stays close to the baseline, and the NF model injects power at larger radii, altering the warm+hot gas distribution in the outer corona. Despite these differences, the SFR and the disc inflow and outflow rates change only marginally across the models. Future work will explore larger energy budgets and replace the scaling-relation prescription with self-consistent accretion onto a live black-hole particle, letting the feedback energy emerge from the accretion history rather than being imposed.