Isotopic Titanium Abundances in Local M Dwarfs

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.

33 pages, 8 figures, accepted for publication in ApJ

References in corpus (5)

• Galactic chemical evolution: Carbon through Zinc
• Oxygen Abundances in Nearby Stars. Clues to the formation and evolution of the Galactic disk
• M dwarfs: effective temperatures, radii and metallicities
• Accurate M Dwarf Metallicities from Spectral Synthesis: A Critical Test of Model Atmospheres
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• Analysis of the TiO isotopologues in stellar optical spectra
• The Rotationally Resolved Infrared Spectrum of TiO and Its Isotopologues
• Chemical Properties of the Local Disk and Halo. II. Abundances of 3745 M dwarfs and Subdwarfs from Improved Model Fitting of Low-Resolution Spectra
• The Missing Link: Testing Galactic Chemical Evolution Models with the First Multi-Isotopic Abundances in Solar Twin Stars