Understanding Lyman-alpha observations with IllustrisTNG

Lyman-alpha (Lyα) emission illuminates much of the high redshift universe and can be used for the study of galaxy evolution and in cosmology. The versatile use of the Lyα line comes at the price of a hard to interpret observational signal given the line’s resonant nature and interplay of different relevant spatial scales. I will present voroILTIS, a Lyα radiative transfer code to be run on top of meshless hydrodynamic simulations such as IllustrisTNG, and show its application to various open questions including the nature of Lyman-alpha halos, the intergalactic medium as a shaping factor of Lyman-alpha spectra and possible distortion effects arising for Lyα based cosmological surveys. I will compare my key findings, such as the computed surface-brightness profiles around star-forming galaxies between z=2 and z=5 to recent MUSE observations, and conclude by providing the next steps needed to further advance our understanding of Lyα observations with voroILTIS.