The Intertwined Feedback Processes in Massive Galaxies

Connecting the cosmological large-scale context with small-scale physics is of paramount importance to fully understand the underlying physical processes that regulate the structure of the gas within the galaxy, star formation, and the driving of galactic outflows. In this talk, I will present two different sets of simulations for a complementary view:  1) idealised simulations of galaxies in isolated halos with a distinct multi-phase ISM, and 2) cosmological zoom simulations that place the galaxy in its full cosmological environment but treat the ISM approximately. I will show how using both approaches allows me to include and resolve relevant physical processes for the ISM, as well as the circumgalactic medium (CGM), to improve our understanding of them in the evolution of galaxies. Such an approach is critical for understanding the physical processes that affect the multi-phase ISM structure and energetics, and drive large-scale winds. Specifically, I will show that in high-resolution simulations of Milky-Way (MW) like simulations a realistic three-phase structure develops with the inclusion of radiation from massive stars, SN feedback, and cooling and gravity. In these simulations the star formation rate naturally follows observed scaling relation for the local MW gas surface densities. I will argue that such insight and effort is vital to understand the coupling efficiency of different AGN feedback channels with the surrounding gas. Simultaneously, it is important to also account for the large-scale environment. The exact physical state of the circumgalactic medium is still unclear. One of the most interesting unknowns is the role of cosmic rays. I will present new cosmological zoom simulations of galaxies and show how the cosmic rays influence the state of the CGM of different galaxies over cosmic time.