The search for Population III stars

TL;DR

This paper discusses the ongoing search for Population III stars, the universe's first stars, highlighting recent observational efforts and potential candidates, but notes that definitive detection remains elusive.

Contribution

It emphasizes the importance of detecting Population III stars and points out overlooked candidate galaxies, proposing new observational targets for future searches.

Findings

Potential detection of PopIII stars in a lensed galaxy at z=3.4

Search for HeII 1640A line in a galaxy at z=6.5 was inconclusive

Highlights the need for further observations to confirm PopIII stars

Abstract

Population III stars, the first generation of stars formed from primordial Big Bang material with a top-heavy IMF, should contribute substantially to the Universe reionization and they are crucial for understanding the early metal enrichment of galaxies. Therefore it is very important that these objects, foreseen by theories, are detected by observations. However PopIII stars, searched through the HeII 1640A line signature, have remained elusive. We report about the search for the HeII line in a galaxy at z=6.5, which is a very promising candidate. Unfortunately we are not yet able to show the results of this search. However we call attention to the possible detection of PopIII stars in a lensed HII dwarf galaxy at z=3.4, which appeared in the literature some years ago, but has been overlooked.