Revealing the hidden nature of the circumgalactic and intergalactic media

Drew Miles, PhD

The majority of baryonic matter in our Universe is contained in the vast reservoirs of gas around and between galaxies — the circumgalactic medium (CGM) and intergalactic medium (IGM), respectively. As low-density reservoirs with low surface brightness, however, the CGM and IGM have been difficult to study directly. In this talk we discuss the significance of the CGM and IGM in galaxy formation and evolution and review recent studies that advance our understanding of these media. We also introduce a new stratospheric balloon instrument, the Stratospheric Cosmic Web Imager, designed to map emission from the CGM and IGM from a high-altitude balloon. Finally, we discuss future applications of next-generation missions that will provide breakthrough observations of CGM/IGM emission.