In my last years at the University of Washington, I worked with Prof. Matt McQuinn on a project aimed to predict the line emission from the CGM of Milky Way-mass galaxies, utilizing column density obervations. By determining the expected emissivity of the CGM in various ultraviolet and optical spectral lines, I sought to inform predictions for proposed observational instruments, such as the UV-sensitive imager Maratus, and observational programs on instruments like the ground-based spectrograph Keck Cosmic Web Imager (KCWI). First, I compiled atomic data, like collision strengths and fractions of spontaneous transitions, from databases such as CHIANTI (Del Zanna et al. 2021). I then built a Python function that calculates a spectral line’s estimated intensity (see figure below) using these atomic values, an ion’s fractional abundance generated by the spectral synthesis code, Cloudy version c17.02 (Ferland et al. 2017), and a model of the CGM’s temperature and density distribution. I found the emission lines [O III] 5007 Å and [N II] 6583 Å, while faint, may be within detection limits of KCWI, and O VI 1032, 1038 Å would be detectable with a 1-meter space telescope. In addition to being feasibly detected, measuring these lines would provide insightful constraints on the density and thermal state of the CGM