Effects of Lyman alpha scattering in the IGM on clustering statistics of Lyman alpha emitters

TL;DR

This study examines how Lyman alpha scattering in the intergalactic medium influences the observed clustering of Lyman alpha emitters, revealing correlations with large-scale structure and halo properties at high redshifts.

Contribution

It provides the first detailed analysis of Lyman alpha radiative transfer effects on galaxy clustering using high-resolution simulations at multiple redshifts.

Findings

Observed Lyman alpha fraction correlates with density and velocity gradients.

No significant deformation of the 2-point correlation function due to radiative transfer effects.

Correlation between Lyman alpha fraction and dark matter halo angular momentum.

Abstract

We investigate the correlations between the observed fraction of Lyman alpha emission from star-forming galaxies and the large scale structure by post-processing snapshots of a large, high resolution hydrodynamical simulation with a Lyman alpha radiative transfer code at redshifts z=4, 3, 2. We find correlations of the observed fraction with density, density gradient along the line of sight, velocity and velocity gradient along the line of sight, all within the same order of magnitude (tens of percent). Additionally, a correlation with the angular momentum of the dark matter halo is detected. In contrast to a previous study, we find no significant deformation of the 2-point correlation function due to selection effects from radiative transfer in the IGM within the limited statistics of the simulation volume.