Simulations and modeling of multiphase gas in the circumgalactic medium

Abstract

The circumgalactic medium (CGM) plays a critical role in galactic evolution, serving as a complex gaseous environment that hosts most of a galaxy's baryonic matter and mediates intricate gas flows. This thesis presents groundbreaking research into the CGM's physics through advanced numerical simulations and innovative analytical models, making significant contributions to our understanding of galactic gas dynamics. The research introduces several key scientific achievements. First, the study developed advanced simulation techniques that more accurately represent supernova-driven outflows by precisely modeling the downstream expansion of galactic winds. This approach provides a more nuanced understanding of cold gas cloud formation within galactic winds. A novel analytic model was developed to explain gas flow mechanisms at the interface between hot and cold gas phases, with particular emphasis on small-scale cooling processes surrounding cold clouds in the CGM. This work represents a substantial advancement in comprehending the microscopic thermal dynamics of galactic gas environments. Moreover, the thesis pioneered a new class of statistical CGM models that generate synthetic observational data more closely aligned with multi-wavelength observations. By utilizing both idealized and cosmological simulations, the research offers unprecedented insights into the structural and dynamical characteristics of the circumgalactic medium.