Isotopic Titanium Abundances in Local M Dwarfs

TL;DR

This study measures titanium isotopic ratios in 11 M dwarfs across different galactic populations, finding ratios similar to solar values and consistent with some chemical evolution models despite discrepancies in titanium abundance predictions.

Contribution

It provides the first isotopic titanium measurements for M dwarfs across multiple galactic populations, revealing uniform ratios and informing chemical evolution models.

Findings

Isotopic ratios are consistent with solar system values across the sample.

No significant difference between thin and thick disk stars' isotopic ratios.

Galactic chemical evolution models align with observed ratios despite underpredicting [Ti/Fe].

Abstract

Relative abundances of the five stable isotopes of titanium (^46Ti to ^50Ti) are measured for 11 M dwarfs belonging to the thin disk (four stars), thick disk (three stars), the halo (one star), and either the thick or the thin disk (three stars). Over the metallicity range of the sample (-1<[Fe/H]<0), the isotopic ratios are approximately constant to the solar system ratios. There is no discernible difference between the isotopic ratios for thin and thick disk stars. Isotopic ratios are in fair accord with recent calculations of Galactic chemical evolution despite the fact that such calculations underpredict [Ti/Fe] by about 0.4 dex at all metallicities.