Oral Presentation
Testing Lyman alpha emitters and Lyman-break galaxies as tracers of large-scale structures in the high-redshift universe.
Presenter: Sang Hyeok Im (Seoul National University)
Lyman alpha emitters (LAEs) and Lyman-break galaxies (LBGs) are known as useful tracers of large-scale structures at high redshifts, which have been not examined seriously. In this work, we test LAEs and LBGs as tracers of large-scale structures at high redshifts. To do that, we first construct LAE and LBG samples from the data of Horizon Run 5 cosmological hydrodynamical simulation at three redshifts: z~2.4, 3.1, and 4.5. We then identify filamentary structures of those LAEs and LBGs, as well as all galaxies and dark matter particles. The density distribution of each sample perpendicular to the filamentary structures of dark matter particles shows that LAEs and LBGs are well concentrated toward dark matter filaments. We also find an empirical fitting formula for the density distribution, Σ = Σ_0 × (1 + Dskel/Dc)^{−α}, which works well for any tracers within 2 cMpc. We then calculate the average thickness of filamentary structures of each sample and find that LAEs and LBGs have thinner filamentary structures than dark matter particles. Finally, we examine the difference between filamentary structures of galaxy samples (i.e., LAEs, LBGs, and all galaxies) and those of dark matter particles. The spatial offsets between filamentary structures of galaxy samples and dark matter particles are comparable with their mean separation. These results imply that LAEs and LBGs could be good tracers of large-scale structures at high redshifts.
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