# Intergalactic Lyman-$α$ haloes before reionization are detectable with JWST

**Authors:** Hamsa Padmanabhan, Abraham Loeb  
**arXiv:** [2404.18998](https://arxiv.org/abs/2404.18998)  
**Date:** 2024-04-29  
**Summary page:** https://www.summarizepaper.com/en/paper/2404.18998v1/

## Key points

- JWST has identified a substantial population of Lyman-alpha emitters at redshifts greater than 10
- Researchers have established constraints on the detectability of intergalactic Lyman-alpha haloes using UV luminosities and data-driven methodology
- Intergalactic scattered intensity manifests in the form of Loeb-Rybicki haloes during pre-reionization and reionization epochs (redshifts 9 to 16)
- Individual haloes with LAE luminosities exceeding $10^{43}$ ergs/s can be discerned at a few sigma level for redshifts below approximately 11
- By stacking approximately 10 haloes, detections are anticipated to extend up to redshift 16
- Discovery and examination of these intergalactic haloes provide insights into neutral intergalactic hydrogen during cosmic reionization period
- Authors Hamsa Padmanabhan from Geneva and Abraham Loeb from Harvard have contributed to this research endeavor spanning various disciplines within astrophysics
- The study comprises 13 pages, 3 figures, and 2 tables, exploring the detectability and implications of intergalactic Lyman-alpha haloes before reionization using JWST observations.

## Summary

The  (JWST) has recently made groundbreaking discoveries in the realm of . Specifically, JWST has identified a substantial population of  at redshifts greater than 10, as well as  reaching out to around redshift 11. Building upon these findings, researchers have utilized observed UV luminosities in conjunction with a data-driven methodology applied at lower redshifts to establish constraints on the detectability of intergalactic . This scattered intensity manifests in the form of Loeb-Rybicki haloes and is particularly relevant during the pre-reionization and reionization epochs spanning approximately redshifts 9 to 16. Through detailed analysis, it has been projected that individual haloes exhibiting LAE luminosities exceeding $10^{43}$ ergs/s can be discerned at a few sigma level for redshifts below approximately 11. Furthermore, by employing a stacking approach involving approximately 10 haloes, detections are anticipated to extend all the way up to redshift 16. The discovery and examination of these intergalactic haloes hold significant promise in shedding light on the state of neutral intergalactic hydrogen during the cosmic reionization period. Authors Hamsa Padmanabhan from Geneva and Abraham Loeb from Harvard have contributed to this research endeavor, which spans across various disciplines within astrophysics including astro-ph.CO and astro-ph.GA. This study comprises 13 pages along with 3 figures and 2 tables, providing a comprehensive exploration into the detectability and implications of intergalactic Lyman-alpha haloes before reionization using JWST observations.