Relation of Observable Stellar Parameters to Mass-Loss Rate of AGB Stars in the LMC

TL;DR

This study derives empirical formulae linking mass-loss rates of AGB stars in the LMC to observable parameters like luminosity, pulsation period, and mass, enhancing understanding of stellar evolution and mass-loss mechanisms.

Contribution

The paper presents new empirical formulae for AGB star mass-loss rates based on extensive observational data, connecting observable parameters with theoretical models.

Findings

Mass-loss rate correlates strongly with luminosity, mass, and pulsation period.

Derived formulae accurately reproduce observed mass-loss rates.

Established new relations between mass-loss rate and stellar color.

Abstract

Using the Riebel et al. (2012) data set for 6,889 pulsating AGB stars in the LMC, we have derived formulae for mass-loss rate as a function of luminosity and pulsation period or luminosity and mass in three ways, for each of five subsets of data: fundamental mode oxygen rich stars, first overtone mode oxygen rich stars stars, fundamental mode carbon stars, first overtone mode carbon stars, and extreme carbon stars. Using the distribution of the stars in period versus luminosity and mass versus luminosity, we are able to derive a power-law fit to the dependence of mass-loss rate on those quantities. This results in formulae that reproduce observed mass-loss rates and are in general agreement with the expectation from mass-loss models that the mass-loss rate is highly sensitive to luminosity, mass, and pulsation period. In the process of carrying out this analysis we have found radius-mass-luminosity and examined pulsation-mass-radius relations using published evolutionary and pulsation models. These allow us to derive mass and radius from the observed quantities luminosity and pulsation period. We also derived new mass-loss rate versus color relations.