The Chemical Evolution of Magnesium Isotopic Abundances in the Solar Neighbourhood

Abstract

The abundance of the neutron-rich magnesium isotopes observed in metal-poor stars is explained quantitatively with a chemical evolution model of the local Galaxy that considers - for the first time - the metallicity-dependent contribution from intermediate mass stars. Previous models that simulate the variation of Mg isotopic ratios with metallicity in the solar neighbourhood have attributed the production of Mg25 and Mg26 exclusively to hydrostatic burning in massive stars. These models match the data well for [Fe/H]>-1.0 but severely underestimate Mg25/Mg24 and Mg26/Mg24 at lower metallicities. Earlier studies have noted that this discrepancy may indicate a significant role played by intermediate-mass stars. Only recently have detailed calculations of intermediate-mass stellar yields of Mg25 and Mg26 become available with which to test this hypothesis. In an extension of previous work, we present a model that successfully matches the Mg isotopic abundances in nearby Galactic disk stars through the incorporation of nucleosynthesis predictions of Mg isotopic production in asymptotic giant branch stars.

arXiv comment9 pages, 6 figures, to appear in Publications of the Astronomical Society of Australia (PASA) in 2003, vol. 20, No. 4

References in corpus (9)

• On the variation of the Initial Mass Function
• Nucleosynthesis in Chandrasekhar Mass Models for Type Ia Supernovae and Constraints on Progenitor Systems and Burning-Front Propagation
• Galactic Chemical Evolution: Hydrogen Through Zinc
• Early Star Formation and the Evolution of the Stellar Initial Mass Function in Galaxies
• Massive Stars in the Range $13-25{\mathrm{M}}_{\odot }$: Evolution and Nucleosynthesis. II. the Solar Metallicity Models
• The 12C(alpha,gamma)16O Reaction Rate and the Evolution of Stars in the Mass Range 0.8 < M/M(sun) < 25
• The Isotopic Abundances of Magnesium in Stars
• The Chemical Yields Produced by Zero Metal Massive Stars
• A search for cool subdwarfs: Stellar parameters for 134 candidates

Cited by in corpus (32)

• The Dawes Review 2: Nucleosynthesis and stellar yields of low and intermediate-mass single stars
• The Evolution of Isotope Ratios in the Milky Way Galaxy
• Stellar Abundances in the Solar Neighborhood: The Hypatia Catalog
• Aluminum-, Calcium- And Titanium-Rich Oxide Stardust In Ordinary Chondrite Meteorites
• The evolution of CNO isotopes: a new window on cosmic star-formation history and the stellar IMF in the age of ALMA
• Super and massive AGB stars - III. Nucleosynthesis in metal-poor and very metal-poor stars - Z=0.001 and 0.0001
• Nucleosynthesis Predictions for Intermediate-Mass AGB Stars: Comparison to Observations of Type I Planetary Nebulae
• 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
• Heavy element abundances in giant stars of the globular clusters M4 and M5
• Galactic Chemical Evolution
• Chemical abundances in giants stars of the tidally disrupted globular cluster NGC 6712 from high-resolution infrared spectroscopy
• Higher D or Li: Probes of Physics beyond the Standard Model
• Cosmological implications of dwarf spheroidal chemical evolution
• The Chemical Evolution of Mg Isotopes vs. the Time Variation of the Fine Structure Constant
• The Rise of the AGB in the Galactic Halo: Mg Isotopic Ratios and High Precision Elemental Abundances in M71 Giants
• The Gaia-ESO Survey: A new approach to chemically characterising young open clusters II. Abundances of the neutron-capture elements Cu, Sr, Y, Zr, Ba, La, and Ce
• Magnesium Isotopes in Metal-Poor Dwarfs, the Rise of AGB Stars and the Formation Timescale of the Galactic Halo
• The Fine-structure Constant as a Probe of Chemical Evolution and AGB Nucleosynthesis in Damped Lyman-alpha Systems
• Constraints on Early Nucleosynthesis from the Abundance Pattern of a Damped Ly-alpha System at z = 2.626
• First direct limit on the 334 keV resonance strength in the ${}^{22}$Ne(α,γ)${}^{26}$Mg reaction
• The Cosmic Evolution of Magnesium Isotopes
• Cosmic Chemical Evolution with an Early Population of Intermediate Mass Stars
• Nucleosynthetic yields of Z=$10^{-5}$ intermediate-mass stars
• Carbon and Nitrogen Abundances in Early-type Galaxies
• Clustering in the Stellar Abundances Space
• Nucleosynthetic yields of intermediate-mass primordial to extremely metal-poor stars
• The Chemical Evolution of Globular Clusters - II. Metals and Fluorine
• A formation timescale of the Galactic halo from Mg isotopes in dwarf stars
• Galactic Chemical Evolution Redux: Atomic Numbers 6 < Z < 15
• Magnesium isotope ratios in Milky Way and dwarf galaxy stars
• Using Binary Population Synthesis to Calculate the Yields of Low- and Intermediate-Mass Binary Populations at Low Metallicity
• Globular Cluster Abundances and What They Can Tell Us About Galaxy Formation