KIPAC Seminar: Probing Cosmic Plasmas from Sub-AU to Gigaparsec Scales

Abstract: Most of the ordinary matter in the universe takes the form of diffuse ionized gas, or plasma. Characterizing the full distribution of this plasma is critical to understanding how the universe forms its main structures. In this talk, I will discuss recent breakthroughs in our efforts to resolve the distribution of cosmic plasmas across a vast range of spatial scales, primarily based on observations of pulsars and fast radio bursts (FRBs). These observations are distinct in that they trace plasma densities on galactic and intergalactic scales, as well as sub-au plasma fluctuations. I will present the NE2025 Galactic electron density model, and demonstrate how an up-to-date understanding of the Milky Way’s turbulent ionized gas distribution will reveal extremely diffuse plasmas around and between galaxies, as well as enabling a sharp-eyed view of FRBs’ local environments. Implications for key surveys of the late 2020's, including the Schmidt Observatory System's Deep Synoptic Array, will be discussed.