Baryons: What, When and Where?

TL;DR

This review summarizes the current empirical understanding of baryonic matter distribution in the universe across key redshifts, highlighting observational methods and upcoming space missions' potential impact.

Contribution

It provides a comprehensive overview of baryon observations since reionization, emphasizing milestones at redshifts 3, 1, and 0, and discusses future space missions.

Findings

Baryonic matter distribution varies across redshifts.

Observational techniques have advanced understanding of baryon phases.

Upcoming space missions will significantly enhance baryon studies.

Abstract

We review the current state of empirical knowledge of the total budget of baryonic matter in the Universe as observed since the epoch of reionization. Our summary examines on three milestone redshifts since the reionization of H in the IGM, z = 3, 1, and 0, with emphasis on the endpoints. We review the observational techniques used to discover and characterize the phases of baryons. In the spirit of the meeting, the level is aimed at a diverse and non-expert audience and additional attention is given to describe how space missions expected to launch within the next decade will impact this scientific field.