Work

Radio signatures of a massive black hole in GHZ9 at z ∼ 10

Year: 2025

Type: article

Abstract: ABSTRACT Synergies between the JWST and the Chandra X-ray observatory have advanced the observational frontier by detecting a handful of active galactic nuclei beyond $z \sim$ 10. In particular, the recent discovery of a candidate $\rm 8 \times 10^7$$\mathrm{M}_{\odot }$ black hole (BH) in the galaxy GHZ9 at $z =$ 10.4 favours massive seed formation channels for these objects. Motivated by prospects for their detection in radio by recent studies, we estimate radio fluxes for GHZ9 and explore the possibility of their detection with the Square Kilometer Array (SKA) and next-generation Very Large Array (ngVLA). We find that ngVLA should be able to detect radio emission from GHZ9 for integration times as short as 1 h, while SKA will require integration times of up to 100 h. We also find that radio emission from the BH can be distinguished from that due to H ii regions and supernovae in its host galaxy. The detection of a few hundred nJy radio signal at frequencies $>\!\! 2$ GHz will be a smoking gun for the presence of a BH in GHZ9.

Source: Monthly Notices of the Royal Astronomical Society

DOI: 10.1093/mnras/staf242

Authors: Muhammad A Latif, Daniel J Whalen

Institutions: United Arab Emirates University, University of Portsmouth

Language: English

Topic: Galaxies: Formation, Evolution, Phenomena

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,046

Funder: United Arab Emirates University