Radio Power from Direct-Collapse Black Holes

TL;DR

This paper estimates the radio emission from direct-collapse black holes at high redshifts, suggesting that upcoming radio telescopes like SKA and ngVLA could detect and study these early universe objects, shedding light on quasar formation.

Contribution

The study provides the first estimates of radio flux from DCBHs at high redshift, highlighting the potential of future radio telescopes to detect and explore their properties.

Findings

DCBHs could be detected at z ~ 8 by SKA-FIN survey.

SKA and ngVLA could discover millions of BHs up to z ~ 20.

Radio observations can probe early quasar formation pathways.

Abstract

Direct-collapse black holes (DCBHs) forming at $z \sim$ 20 are currently the leading candidates for the seeds of the first quasars, over 200 of which have now been found at $z >$ 6. Recent studies suggest that DCBHs could be detected in the near infrared by the James Webb Space Telescope, Euclid, and the Roman Space Telescope. However, new radio telescopes with unprecedented sensitivities such as the Square Kilometer Array (SKA) and the Next-Generation Very Large Array (ngVLA) may open another window on the properties of DCBHs in the coming decade. Here we estimate the radio flux from DCBHs at birth at $z =$ 8 - 20 with several fundamental planes of black hole accretion. We find that they could be detected at $z \sim$ 8 by the SKA-FIN all-sky survey. Furthermore, SKA and ngVLA could discover 10$^6$ - 10$^7$ $M_{\odot}$ BHs out to $z \sim$ 20, probing the formation pathways of the first quasars in the Universe.