Distinguishing AGN from starbursts as the origin of double peaked Lyman-Alpha Emitters in the reionization era

TL;DR

This paper investigates whether obscured active galactic nuclei (AGN) can explain the double-peaked Lyman-Alpha emission profiles observed in high-redshift galaxies during reionization, using modeling and future observational prospects.

Contribution

It provides a framework to distinguish AGN from starburst origins in high-redshift LAEs by analyzing their emission profiles and luminosities, and predicts observational signatures.

Findings

Estimated the UV and X-ray luminosities of AGN needed for double-peaked profiles.

Compared AGN obscuration levels with quasar samples at similar epochs.

Proposed future X-ray, radio, and JWST observations to test AGN contribution.

Abstract

We discuss the possible origin of the double-peaked profiles recently observed in Lyman-Alpha Emitters (LAEs) at the epoch of reionization ($z \gtrsim 6.5$) from obscured active galactic nuclei (AGN). Combining the extent of the Lyman-$\alpha$ near-zones estimated from the blue peak velocity offset in these galaxies, with the ionizing emissivity of quasars at $z \gtrsim 6$, we forecast the intrinsic UV and X-ray luminosities of the AGN needed to give rise to their double-peaked profiles. We also estimate the extent of the obscuration of the AGN by comparing their luminosities to those of similar quasar samples at these epochs. Future X-ray and radio observations, as well as those with the ${James \ Webb \ Space \ Telescope}$, will be valuable tools to test the AGN contribution to the intergalactic-scale ionization zones of high-redshift LAEs.