The dust production rate of AGB stars in the Magellanic Clouds

TL;DR

This study compares theoretical dust yields from AGB stars with observed dust production rates in the Magellanic Clouds, highlighting the importance of mass-loss efficiency and metallicity dependence in dust enrichment processes.

Contribution

It provides a detailed comparison between models and observations, emphasizing the role of metallicity and mass-loss rates in dust production by AGB stars.

Findings

Models reproduce LMC C-AGB DPR only with efficient mass loss.

Over-prediction of DPR in SMC suggests metallicity-dependent mass loss.

AGB stars contribute significantly to dust mass, especially in the LMC.

Abstract

We compare theoretical dust yields for stars with mass 1 Msun < mstar < 8 Msun, and metallicities 0.001 < Z < 0.008 with observed dust production rates (DPR) by carbon- rich and oxygen-rich Asymptotic Giant Branch (C-AGB and O-AGB) stars in the Large and Small Magellanic Clouds (LMC, SMC). The measured DPR of C-AGB in the LMC are reproduced only if the mass loss from AGB stars is very efficient during the carbon-star stage. The same yields over-predict the observed DPR in the SMC, suggesting a stronger metallicity dependence of the mass-loss rates during the carbon- star stage. DPR of O-AGB stars suggest that rapid silicate dust enrichment occurs due to efficient hot-bottom-burning if mstar > 3 Msun and Z > 0.001. When compared to the most recent observations, our models support a stellar origin for the existing dust mass, if no significant destruction in the ISM occurs, with a contribution from AGB stars of 70% in the LMC and 15% in the SMC.