# On the Relation of Silicates and SiO Maser in Evolved Stars

## TL;DR

This study investigates the relationship between SiO maser emission and silicate dust emission in evolved stars, finding a correlation that supports SiO as seed nuclei for silicate dust formation, but no link to silicate crystallinity.

## Contribution

It provides observational evidence of a correlation between SiO maser power and silicate dust emission, supporting the hypothesis that SiO molecules seed silicate dust in evolved stars.

## Key findings

- SiO maser and silicate emission powers are correlated.
- No correlation between SiO maser and silicate crystallinity.
- Silicate crystallinity may be independent of mass loss rate.

## Abstract

The SiO molecule is one of the candidates for the seed of silicate dust in the circumstellar envelope of evolved stars, but this opinion is challenged. In this work we investigate the relation of the SiO maser emis- sion power and the silicate dust emission power. With both our own observation by using the PMO/Delingha 13.7-m telescope and archive data, a sample is assembled of 21 SiO v=1,J=2-1 sources and 28 SiO v=1,J=1- 0 sources that exhibit silicate emission features in the ISO/SWS spectrum as well. The analysis of their SiO maser and silicate emission power indicates a clear correlation, which is not against the hypothesis that the SiO molecules are the seed nuclei of silicate dust. On the other hand, no correlation is found between SiO maser and silicate crystallinity, which may imply that silicate crystallinity does not correlate with mass loss rate.