Resolving the intergalactic medium with tomographic reconstructions

Tue, May 05, 2015

Cosmology seminar event image

Despite keen interest in how clusters form, the study of early cluster formation is observationally limited: clusters are rare and surveying large volumes is expensive. Today, there are only a handful of known z > 2 protoclusters. At the same time, cosmic voids have received renewed interest as tracers for an AP test and testing modified-gravity models, but current void samples are limited to z < 1. I will discuss how we can use densely packed Lyman-alpha forest sightlines to directly map large scale structure at z = 2 – 3, and how we can find protoclusters and voids using the maps. Using our new Wiener Filter code on sightlines with average separations of 2 – 3 Mpc/h, we can create high-quality maps of the IGM. With a resolution of a few Mpc, the maps clearly pick up protoclusters and voids, both with radii of up to 10 Mpc/h at z = 2.5. I will present the characteristic signals of these objects in the maps and forecasts for samples in upcoming surveys.