The MUSE-Wide survey: Three-dimensional clustering analysis of Lyman-α emitters at 3.3 < z < 6

¹ Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
e-mail: yherreroalonso@aip.de
² Universidad Nacional Autónoma de México, Instituto de Astronomía (IA-UNAM-E), AP 106, Ensenada, 22860 BC, Mexico
³ Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix, Switzerland
⁴ Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
⁵ European Southern Observatory, Av. Alonso de Córdova 3107, 763 0355 Vitacura, Santiago, Chile
⁶ Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands
⁷ Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland
⁸ Kapteyn Astronomical Institute, University of Groningen, Landleven 12, 9747 AD Groningen, The Netherlands
⁹ Univ. Lyon, Univ. Lyon1, ENS de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR 5574, 69230 Saint-Genis-Laval, France

Received: 30 April 2021
Accepted: 6 July 2021

Abstract

We present an analysis of the spatial clustering of 695 Lyα-emitting galaxies (LAEs) in the MUSE-Wide survey. All objects have spectroscopically confirmed redshifts in the range 3.3 < z < 6. We employed the K-estimator, an alternative clustering statistic, adapted and optimized for our sample. We also explore the standard two-point correlation function approach, which is however less suited for a pencil-beam survey such as ours. The results from both approaches are consistent. We parametrize the clustering properties in two ways, (i) following the standard approach of modelling the clustering signal with a power law (PL), and (ii) adopting a halo occupation distribution (HOD) model of the two-halo term. Using the K-estimator and applying HOD modelling, we infer a large-scale bias of b_HOD = 2.80_−0.38^+0.38 at a median redshift of the number of galaxy pairs ⟨z_pair⟩ ≃ 3.82, while the best-fit power-law analysis gives b_PL = 3.03_−0.52^+1.51 (r₀ = 3.60_−0.90^+3.10 comoving h⁻¹ Mpc and γ = 1.30_−0.45^+0.36). The implied typical dark matter halo (DMH) mass is log(M_DMH/[h⁻¹ M_⊙]) = 11.34_−0.27^+0.23 (adopting b = b_HOD and assuming σ₈ = 0.8). We study possible dependencies of the clustering signal on object properties by bisecting the sample into disjoint subsets, considering Lyα luminosity, UV absolute magnitude, Lyα equivalent width, and redshift as variables. We find no evidence for a strong dependence on the latter three variables but detect a suggestive trend of more luminous Lyα emitters clustering more strongly (thus residing in more massive DMHs) than their lower Lyα luminosity counterparts. We also compare our results to mock LAE catalogs based on a semi-analytic model of galaxy formation and find a stronger clustering signal than in our observed sample, driven by spikes in the simulated z-distributions. By adopting a galaxy-conserving model we estimate that the Lyα-bright galaxies in the MUSE-Wide survey will typically evolve into galaxies hosted by halos of log(M_DMH/[h⁻¹ M_⊙]) ≈ 13.5 at redshift zero, suggesting that we observe the ancestors of present-day galaxy groups.