Clustering dependence on Lyman-$\alpha$ luminosity from MUSE surveys at $3<z<6$

TL;DR

This study examines how the clustering of Lyman-alpha emitters at redshifts 3 to 6 depends on their luminosity, revealing a strong correlation between higher luminosity and increased clustering strength and halo mass.

Contribution

It provides the first detailed analysis of the luminosity dependence of LAE clustering using extensive MUSE survey data and advanced HOD modeling.

Findings

Higher luminosity LAEs cluster more strongly and reside in more massive halos.

Satellite fractions are low, supporting single LAE occupancy per dark matter halo.

Clustering dependence on luminosity is statistically significant at 8 sigma.

Abstract

[Abbreviated] We investigate the dependence of Lyman-$\alpha$ emitter (LAE) clustering on Lyman-$\alpha$ luminosity. We use 1030 LAEs from the MUSE-Wide survey, 679 LAEs from MUSE-Deep, and 367 LAEs from the to-date deepest ever spectroscopic survey, the MUSE Extremely Deep Field. All objects have spectroscopic redshifts of $3<z<6$ and cover a large dynamic range of Ly$\alpha$ luminosities: $40.15<\log (L_{\rm{Ly}\alpha}/[\rm{erg \:s}^{-1}])<43.35$. We apply the Adelberger et al. K-estimator as the clustering statistic and fit the measurements with state-of-the-art halo occupation distribution (HOD) models. From the three main data sets, we find that the large-scale bias factor, the minimum mass to host one central LAE, $M_{\rm{min}}$, and (on average) one satellite LAE, $M_1$, increase weakly with an increasing line luminosity. The satellite fractions are $\lesssim10$% ($\lesssim20$%) at $1\sigma$ ($3\sigma$) confidence level, supporting a scenario in which DMHs typically host one single LAE. We next bisected the three main samples into disjoint subsets to thoroughly explore the dependence of the clustering properties on $L_{\rm{Ly}\alpha}$. We report a strong ($8\sigma$) clustering dependence on $L_{\rm{Ly}\alpha}$, where the highest luminosity LAE subsample ($\log(L_{\rm{Ly}\alpha}/[\rm{erg \:s}^{-1}])\approx42.53$) clusters more strongly ($b_{\rm{high}}=3.13^{+0.08}_{-0.15}$) and resides in more massive DMHs ($\log(M_{\rm{h}}/[h^{-1}\rm{M}_{\odot}])=11.43^{+0.04}_{-0.10}$) than the lowest luminosity one ($\log(L_{\rm{Ly}\alpha}/[\rm{erg \:s}^{-1}])\approx40.97$), which presents a bias of $b_{\rm{low}}=1.79^{+0.08}_{-0.06}$ and occupies $\log(M_{\rm{h}}/[h^{-1}\rm{M}_{\odot}])=10.00^{+0.12}_{-0.09}$ halos. We discuss the implications of these results for evolving Ly$\alpha$ luminosity functions, halo mass dependent Ly$\alpha$ escape fractions, and incomplete reionization signatures.