On the Ubiquity of Extreme Baryon Concentrations in the Early Universe

TL;DR

This paper explores the physical conditions in the early Universe that favored the formation of extreme baryon concentrations like globular clusters and supermassive black holes, highlighting their prevalence at high redshifts.

Contribution

It proposes a novel explanation linking low angular momentum and extended feedback-free periods to the formation of baryon concentrations in the early Universe.

Findings

Extreme baryon concentrations are common at high redshifts.

Low angular momentum and feedback-free periods are key conditions for formation.

Formation of such structures becomes rarer at lower redshifts.

Abstract

Early JWST observations have revealed the ubiquitous presence in the early Universe, up to z about 16, of extreme baryon concentrations, namely forming globular clusters, extremely dense galaxies that may or may not be UV bright, and supermassive black holes in relatively low-mass galaxies. This paper is trying to pinpoint which physical conditions may have favored the formation of such concentrations, that appear to be very common at high redshifts while their formation being progressively more and more rare at lower redshifts. Building on local globular cluster evidence, it is argued that such conditions can consist in a combination of a 10 Myr extended feedback free time, coupled to low angular-momentum densities in deep local minima of the ISM vorticity field, where baryon concentrations are more likely to form. It is argued that the former condition would follow from more massive stars failing to explode as supernovae, and the latter one from low vorticity prevailing in the early Universe, in contrast to later times with their secular increase of the angular momentum density due to the cumulative effect of tidal interactions.