Lyman-alpha intensity mapping in the Hobby-Eberly Telescope Dark Energy Experiment

The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is a cosmology survey designed to map out one million galaxies in the distant Universe. In this project, a team of scientists from the Missouri University of Science and Technology will pioneer a method for mapping matter in the universe, called Line Intensity Mapping. The spectrum of light on each direction on the sky can reveal a map of undetected galaxies along the line of sight, which comes from special Lyman-alpha photons that were emitted by hydrogen gas in those galaxies and then were redshifted to a particular wavelength in the observed spectrum. To interpret the HETDEX data, the team will construct simulated data from theoretical simulations of the universe. As part of this project, the team will offer summer workshops for undergraduate students to teach them data science skills and for Missouri K-12 educators. The goal of this project is to detect and interpret the Lyman-alpha intensity mapping signal on large scales at 1.9<z<3.5 in HETDEX. Specifically, the team will measure the cross-correlation signal between Lyman-alpha emitters (LAE) and the Lyman-alpha intensity map in the HETDEX survey. To properly test the analysis pipeline and interpret the measurement, the team will make full use of empirical but realistic synthetic galaxy simulations as well as a hydrodynamical simulation, incorporating the physics of radiative transfer. The mock simulations will also be useful to understand how LAE galaxies formed and evolved and how Lyman-alpha photons propagate through the large-scale structure. Scientific products of this work will include the synthetic galaxy simulations as well as the analysis pipeline, which will be made available publicly for wider use in the community. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.