Speaker
Jo Barnes
(University of St Andrews)
Description
We investigate 3D photoionisation models of the Diffuse Ionised Gas (DIG). Our simulations show that in a supernova-driven, turbulent magnetised medium photons from OB stars in the Galactic plane are able to travel many kiloparsecs and reach heights required to ionise the DIG. To reach these heights photons travel through ?bubbles? evacuated by supernovae close to the midplane of the simulations while travelling through diffuse low density regions at large heights. The ionising luminosity required to create the DIG in our simulations is within the Galactic Lyman continuum budget. We also investigate the impact of additional heating on diagnostic line ratios at large height and find that photoionisation heating alone, without the addition of a heating term that dominates at low density is unable to reproduce the observed ratios. The scale height of H? intensity in our simulations is smaller than that observed as a result of insufficient vertical pressure support.
Author
Jo Barnes
(University of St Andrews)