# Limits on the luminosity function of Ly-alpha emitters at z = 7.7

## TL;DR

This study investigates the Ly-alpha luminosity function at redshift 7.7 using narrow-band imaging, providing insights into galaxy evolution and re-ionization, but requires spectroscopic confirmation for definitive results.

## Contribution

First measurement of the Ly-alpha luminosity function at z=7.7 using narrow-band imaging, offering new constraints on high-redshift galaxy populations.

## Key findings

- Derived a luminosity function from 7 candidate LAEs at z~7.7.
- Possible indication of brighter LAEs than expected from lower redshift data.
- Results are preliminary and need spectroscopic confirmation.

## Abstract

The Ly-alpha luminosity function (LF) of high-redshift Ly-alpha emitters (LAEs) is one of the few observables of the re-ionization epoch accessible to date with 8-10 m class telescopes. The evolution with redshift allows one to constrain the evolution of LAEs and their role in re-ionizing the Universe at the end of the Dark Ages. We have performed a narrow-band imaging program at 1.06 microns at the CFHT, targeting Ly-alpha emitters at redshift z ~ 7.7 in the CFHT-LS D1 field. From these observations we have derived a photometric sample of 7 LAE candidates at z ~ 7.7. We derive luminosity functions for the full sample of seven objects and for sub-samples of four objects. If the brightest objects in our sample are real, we infer a luminosity function which would be difficult to reconcile with previous work at lower redshift. More definitive conclusions will require spectroscopic confirmation.