Si Isotopic Ratios in Mainstream Presolar SiC Grains Revisited

Abstract

Although mainstream SiC grains, the major group of presolar SiC grains found in meteorites, are believed to have originated in the expanding envelope of asymptotic giant branch (AGB) stars during their late carbon-rich phases, their Si isotopic ratios show a distribution that cannot be explained by nucleosynthesis in this kind of stars. Previously, this distribution has been interpreted to be the result of contributions from many AGB stars of different ages whose initial Si isotopic ratios vary due to the Galactic chemical evolution of the Si isotopes. This paper presents a new interpretation based on local heterogeneities of the Si isotopes in the interstellar medium at the time the parent stars of the mainstream grains were born. Recently, several authors have presented inhomogeneous chemical evolution models of the Galactic disk in order to account for the well known evidence that F and G dwarfs of similar age show an intrinsic scatter in their elemental abundances.

Accepted for publication by ApJ. 19 pages of text + 17 figures and 4 tables

Cited by in corpus (35)

• The Dawes Review 2: Nucleosynthesis and stellar yields of low and intermediate-mass single stars
• Galactic Evolution of Sr, Y, Zr: A Multiplicity of Nucleosynthetic Processes
• Evolution, nucleosynthesis and yields of low mass AGB stars
• Evolution, nucleosynthesis and yields of low mass AGB stars at different metallicities (II): the FRUITY database
• The Evolution of Isotope Ratios in the Milky Way Galaxy
• The Element Abundances in Bare Planetary Nebula Central Stars and the Shell Burning in AGB Stars
• s-Process Nucleosynthesis in AGB Stars: A Test for Stellar Evolution
• Presolar Grains from Novae
• Aluminum-, Calcium- And Titanium-Rich Oxide Stardust In Ordinary Chondrite Meteorites
• Presolar grains from meteorites: Remnants from the early times of the solar system
• On Variations Of Pre-Supernova Model Properties
• Coordinated Analyses of Presolar Grains in the Allan Hills 77307 and Queen Elizabeth Range 99177 Meteorites
• Lead: Asymptotic Giant Branch production and Galactic Chemical Evolution
• The Uncertainties in the 22Ne + alpha-capture Reaction Rates and the Production of the Heavy Magnesium Isotopes in Asymptotic Giant Branch Stars of Intermediate Mass
• XMM-Newton observation of 4U 1820-30: Broad band spectrum and the contribution of the cold interstellar medium
• Correlated Strontium and Barium Isotopic Compositions of Acid-Cleaned Single Silicon Carbides from Murchison
• Stellar Origins of Extremely ${}^{\text{13}}C$- and ${}^{15}N$-enriched Presolar SiC Grains: Novae or Supernovae?
• The impact of updated Zr neutron-capture cross sections and new asymptotic giant branch models on our understanding of the s process and the origin of stardust
• The abundance of 36S in IRC+10216 and its production in the Galaxy
• Do meteoritic silicon carbide grains originate from asymptotic giant branch stars of super-solar metallicity?
• Origin of large meteoritic SiC stardust grains in metal-rich AGB stars
• Decoding the message from meteoritic stardust silicon carbide grains
• The impact of the 18F(a,p)21Ne reaction on asymptotic giant branch nucleosynthesis
• Cosmic nucleosynthesis: a multi-messenger challenge
• Partial mixing and the formation of 13C pockets in AGB stars: effects on the s-process elements
• Reaction rate uncertainties and 26Al in AGB silicon carbide stardust
• Cluster analysis of presolar silicon carbide grains: evaluation of their classification and astrophysical implications
• Isotope Anomalies in the Fe-group Elements in Meteorites and Connection to Nucleosynthesis in AGB Stars
• Presolar O- and C-anomalous grains in unequilibrated ordinary chondrite matrices
• Isotopic Titanium Abundances in Local M Dwarfs
• Uniform Silicon Isotope Ratios Across the Milky Way Galaxy
• Can Galactic chemical evolution explain the oxygen isotopic variations in the Solar System?
• Presolar grains
• Impact of newly measured 26Al(n, p)26Mg and 26Al(n, α)23Na reaction rates on the nucleosynthesis of 26Al in stars
• Silicon Isotopic Composition of Mainstream Presolar SiC Grains Revisited: The Impact of Nuclear Reaction Rate Uncertainties