Clustering at high redshift: The connection between Lyman Alpha emitters and Lyman break galaxies

TL;DR

This paper introduces a semi-analytic model that successfully predicts the clustering properties of high-redshift Lyman Alpha Emitters, revealing their connection to Lyman Break Galaxies and explaining observed clustering patterns.

Contribution

The study provides a physically motivated model linking LAE clustering to dark matter halos and LBGs, with predictions matching observations and insights into galaxy populations.

Findings

LAEs reside in ~10^11 M_ halos, smaller than LBGs.

LAEs have weaker clustering than LBGs due to lower halo masses.

LAEs and LBGs are part of the same galaxy population, with different detection efficiencies.

Abstract

We present a physically motivated semi-analytic model to understand the clustering of high redshift Lyman Alpha Emitters (LAEs). We show that the model parameters constrained by the observed luminosity functions, can be used to predict large scale bias and angular correlation function of LAEs. These predictions are shown to reproduce the observations remarkably well. We find that average masses of dark matter halos hosting LAEs brighter than threshold narrow band magnitude ~ 25 are ~ 10^11 M_\odot. These are smaller than that of typical Lyman Break Galaxies (LBGs) brighter than similar threshold continuum magnitude by a factor ~ 10. This results in a smaller clustering strength of LAEs compared to LBGs. However, using the observed relationship between UV continuum and Lyman-alpha luminosity of LAEs, we show that both LAEs and LBGs belong to the same parent galaxy population with narrow band techniques having greater efficiency in picking up galaxies with low UV luminosity. We also show that the lack of evidence for the presence of the one halo term in the observed LAE angular correlation functions can be attributed to sub-Poisson distribution of LAEs in dark matter halos as a result of their low halo occupations.