Where the hot universe meets the energetic universe

          @misc{ pirsa_PIRSA:25070020,
            doi = {10.48660/25070020},
            url = {https://pirsa.org/25070020},
            author = {Das, Sanskriti},
            keywords = {Cosmology},
            language = {en},
            title = {Where the hot universe meets the energetic universe},
            publisher = {Perimeter Institute},
            year = {2025},
            month = {jul},
            note = {PIRSA:25070020 see, \url{https://pirsa.org}}
          }
          

Abstract

The hot circumgalactic medium (CGM), a reservoir of missing baryons, metals, and energy, plays a key role in our understanding of galaxy evolution. However, extraordinary observational challenges make the hot CGM one of the least understood components of galaxies. Studying the hot CGM was not the objective of current X-ray or mm facilities during the design phase. However, as an excellent byproduct, observing the hot CGM has emerged as a promising field over the last two decades, coming at the forefront of priority science goals for the current and upcoming decades. I will discuss three snippets of our recent efforts to detect and characterize the hot CGM: 1) X-raying the Milky Way: Investigating thermal, chemical, and kinematic anomalies; 2) Is CGM detectable? Conducting deep searches in individual external galaxies using X-ray; and 3) Test for self-similarity: stacking many galaxies in mm (Sunyaev-Zeldovich Effect). I will highlight how our findings provide insights into the impact of galactic feedback on the hot CGM, establish our confidence in leveraging current telescopes to inform theoretical simulations, and set a benchmark for designing experiments with next-generation X-ray and mm facilities.