Cake Talk by Zhihui Li from Caltech
The Lyα emission line encodes abundant physical information about its surrounding gaseous medium in a galactic environment. Nevertheless, the resonant nature of Lyα complicates the modeling and interpretation of the line profile. In this talk, I will present the recent developments of Lyα radiative transfer (RT) modeling in a multiphase, clumpy medium and how the model helps us interpret observed Lyα spectra in a more physically realistic context. I will then present a new application of the model, which is to fit the KCWI-observed radially-varying Lyα profiles of a sample of z ~ 2 extreme emission line galaxies in a spatially-resolved manner. Our model successfully reproduces the radial trends of several Lyα spectral properties, including the peak flux ratio, peak separation and flux at the line center, and we reveal the physical reasons for such spatial variations from an RT perspective. Finally, we show that when combined with down-the-barrel UV absorption line observations, our modeling suggests a self-consistent picture of the circumgalactic medium and the galactic fountain.