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# A selection-aware view of black hole–galaxy coevolution at high redshift

## Details

**Authors** Ziparo et al.

**Year** 2026

**Publisher** Astronomy & Astrophysics

**Discipline** Astronomy

**Secondary disciplines** Cosmology

[Read it at the publisher](https://doi.org/10.1051/0004-6361/202659574) 
10.1051/0004-6361/202659574

## In authors' words

### What they found (results)

A forward-modelling Bayesian framework correcting for JWST detection/selection biases on broad-line AGN finds the black hole–stellar mass relation at z~4-6 already matches the local slope and normalization, but with roughly 0.63 dex greater intrinsic scatter than in the nearby universe.

## Commentary

### In short

The black hole (part) and its host galaxy (whole system) are coupled through a mass-scaling relationship whose average form is fixed early in cosmic history, while system-level diversity among individual growth histories shows up specifically as increased scatter in that part-whole relationship rather than a shift in its mean.

**Patterns it shows** S, R

**Added** 2026-09-08

**How to cite this** Ziparo et al. (2026). A selection-aware view of black hole–galaxy coevolution at high redshift. Astronomy & Astrophysics.