| Description: | The time has come for a new electron density model of the Milky Way. Galactic electron density models describe the multi-component, multi-scale structure of the ionized interstellar medium (ISM). These models are routinely used to predict the distances of radio sources lacking independent distance measures, in addition to forward modeling the dispersion and scattering of pulsars, fast radio bursts (FRBs), active galactic nuclei, and masers. In this talk I will discuss the developments motivating construction of a new electron density model, and some key puzzles that face our understanding of multi-scale electron density structure in our Galaxy. Unlike previous models, large-scale surveys of the ionized ISM are being actively folded into the model construction. Specific case studies will be discussed to demonstrate how characterization of the Galactic electron density affects our understanding of extragalactic FRBs and their use as cosmic probes. |
