The detached dust shells of AQ And, U Ant, and TT Cyg

TL;DR

This paper reports the detection and analysis of detached dust shells around three carbon variable stars using Herschel-PACS, providing new insights into their physical properties and correlation with molecular CO data.

Contribution

It presents new Herschel-PACS observations and detailed modeling of detached dust shells around three stars, expanding understanding of their structure and relation to molecular emissions.

Findings

Detection of detached dust shells around three stars.

Correlation between dust shells and CO emission for TT Cyg and U Ant.

Differences observed in other observables for these stars.

Abstract

Detached circumstellar dust shells are detected around three carbon variables using Herschel-PACS. Two of them are already known on the basis of their thermal CO emission and two are visible as extensions in IRAS imaging data. By model fits to the new data sets, physical sizes, expansion timescales, dust temperatures, and more are deduced. A comparison with existing molecular CO material shows a high degree of correlation for TT Cyg and U Ant but a few distinct differences with other observables are also found.