Evaluating Lyα Emission as a Tracer of the Largest Cosmic Structure at z ∼ 2.47

Abstract The discovery and spectroscopic confirmation of Hyperion, a protosupercluster at z ∼ 2.47, provides an unprecedented opportunity to study distant galaxies in the context their large-scale environment. We carry out deep narrowband imaging ≈1° × 1° region around Hyperion select 157 Ly α emitters (LAEs). inferred LAE overdensity is δ g ≈ 40 within effective volume 30 20 15 cMpc 3 , consistent with fact that composed multiple protoclusters will evolve into supercluster total mass M tot 1.4 10 ⊙ = 0. distribution LAEs closely mirrors known members, tracing protocluster cores extended filamentary arms connected them, suggesting they trace same structure. By cross-correlating positions H i tomography data, we find weak evidence may be less abundant highest regions, perhaps because suppressed such regions. hosts large population active galactic nuclei (AGNs) 12 times more than field. prevalence AGNs regions hints possibility triggered by physical processes occur frequently dense environments, as galaxy mergers. Our demonstrates reliable markers largest cosmic structures. When combined ongoing upcoming surveys, wide-field has potential advance our knowledge formation evolution structures inhabitants.