Early star-forming galaxies and the reionization of the Universe

TL;DR

This paper discusses the discovery and study of early star-forming galaxies at around 800 million years after the Big Bang, highlighting their role in reionizing the universe and recent observational advances.

Contribution

It reviews recent observational progress and new techniques for understanding the properties and cosmic impact of the earliest galaxies.

Findings

Discovery of galaxies at ~800 million years old

Ultraviolet radiation from early galaxies likely caused reionization

Development of new methods to analyze distant galaxies

Abstract

Star forming galaxies represent a valuable tracer of cosmic history. Recent observational progress with Hubble Space Telescope has led to the discovery and study of the earliest-known galaxies corresponding to a period when the Universe was only ~800 million years old. Intense ultraviolet radiation from these early galaxies probably induced a major event in cosmic history: the reionization of intergalactic hydrogen. New techniques are being developed to understand the properties of these most distant galaxies and determine their influence on the evolution of the universe.