Extragalactic Radio Sources as a Piece of the Cosmological Jigsaw

TL;DR

Extragalactic radio sources provide crucial insights into cosmological evolution, black hole physics, and galaxy formation, with simulations suggesting they influence star formation and gas dynamics in the early Universe.

Contribution

This paper presents new simulations showing how radio sources heat gas, enhance star formation, and interact with black holes, advancing understanding of their role in galaxy evolution.

Findings

Radio sources heat hot halo gas and boost star formation.

Jet-environment interactions reveal black hole physics.

Radio sources influence early Universe galaxy formation.

Abstract

Early on, extragalactic radio sources have pointed to a cosmologically evolving Universe. They were also an important piece of evidence for the existence of supermassive black holes, now thought to be a key component of galaxies. The observation that the power of radio sources increases with redshift, whereas the cosmological assembly of mass proceeds vice versa means that radio sources have their strongest impact in the early Universe. Our simulations suggest that radio sources heat hot halo gas, boost star formation in disc galaxies and other cold gas in the vicinity, possibly filaments, by a surround and squash mechanism. They might cause gaseous outflows in connection with stellar feedback. This might be an important mode of star formation for forming massive galaxies. Analysis of the jet-environment interaction may provide insights into black-hole physics and jet formation, e.g., rotational energy extraction (Blandford-Znajek) or how frequent black-hole binaries or multiple systems are. The former relates to fundamental questions about the nature of black holes. The latter is expected from hierarchical cosmology. Extragalactic radio sources thus continue to corroborate the cosmological picture and lead the way towards new, exciting discoveries.