Emission Tomography of the
Cosmic Web at Cosmic Noon
Abstract: Deep integral-field and narrowband surveys now detect faint,
extended Lyman-alpha (Lyα) emission from the circumgalactic medium
and, increasingly, from diffuse gas in cosmic filaments. I will review recent
measurements and their interpretation, highlighting how galaxy and gas
physics, as well as radiative transfer, complicate the mapping from
surface brightness to gas density and kinematics. I will then discuss how
modern galaxy formation simulations, coupled to Lyα radiative transfer
calculations, are being used to build forward models for large-volume
surveys. Finally, I will present first steps toward physics-informed
emission tomography: inference and reconstruction methods that connect
simulations and observations of the gas and galaxy distribution, enabled
by differentiable simulators.