# Dust production scenarios in galaxies at z ~ 6-8.3

## TL;DR

This study investigates dust production in high-redshift galaxies, concluding that supernovae or non-stellar processes like grain growth are likely responsible for observed dust, as AGB stars alone are insufficient.

## Contribution

It provides new estimates of dust yields from AGB stars and supernovae at z ~ 6-8.3, highlighting the need for efficient supernovae or non-stellar mechanisms to explain observed dust.

## Key findings

- AGB stars cannot account for observed dust masses.
- Supernovae would need maximum efficiency without dust destruction.
- Grain growth in the interstellar medium is a plausible dust source.

## Abstract

The mechanism of dust formation in galaxies at high redshift is still unknown. Asymptotic giant branch (AGB) stars and explosions of supernovae (SNe) are possible dust producers, and non-stellar processes may substantially contribute to dust production, for example grain growth in the interstellar medium (ISM). Our aim is to determine the contribution to dust production of AGB stars and SNe in nine galaxies at z ~ 6-8.3, for which observations of dust have been recently attempted. In order to determine the origin of the observed dust we have determined dust yields per AGB star and SN required to explain the total amounts of dust in these galaxies. We find that AGB stars were not able to produce the amounts of dust observed in the galaxies in our sample. In order to explain these dust masses, SNe would have to have maximum efficiency and not destroy the dust which they formed. Therefore, the observed amounts of dust in the galaxies in the early universe were formed either by efficient supernovae or by a non-stellar mechanism, for instance the grain growth in the interstellar medium.