The Impact of the New ${}^{59}$Fe Decay Rates on ${}^{60}$Fe and ${}^{26}$Al Nucleosynthesis in Massive Stars

Abstract

The diffuse $\gamma$-ray emission from short-lived radioactive ${}^{26}$Al and ${}^{60}$Fe provides a direct probe of ongoing nucleosynthesis in the Galaxy. However, theoretical models have long struggled to reproduce the observed ${}^{60}$Fe/${}^{26}$Al flux ratio, typically predicting values significantly higher than constraints derived from INTEGRAL/SPI observations. In this work, we investigate the impact of the recently measured, temperature-dependent stellar ${\beta }^{-}$ decay rate of ${}^{59}$Fe on the nucleosynthesis of these isotopes. We compute a grid of non-rotating massive star models ($14$-$80$ M${}_{\odot }$) at solar metallicity using the MESA code, coupled with a rigorous numerical resolution analysis. We find that the updated rate significantly suppresses the net production of ${}^{60}$Fe by approximately 0.28 dex ($\sim 47\%$) compared to models using LMP theoretical rates, while leaving ${}^{26}$Al yields virtually unchanged. This reduction is primarily driven by the enhanced ${\beta }^{-}$ decay during convective carbon shell burning. Integrating these yields over a standard Salpeter Initial Mass Function, we predict a Galactic flux ratio of $\sim 0.18$, which is in excellent agreement with the observed value of $0.184\pm 0.042$. Furthermore, this ratio exhibits a weak dependence on the IMF slope. Our results indicate that the updated nuclear physics input significantly alleviates the long-standing ${}^{60}$Fe overproduction problem, bringing theoretical predictions into much closer alignment with current Galactic observations.

arXiv commentAccepted for publication in The Astrophysical Journal (ApJ)

References in corpus (41)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
• Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions
• Modules for Experiments in Stellar Astrophysics (MESA): Convective Boundaries, Element Diffusion, and Massive Star Explosions
• Mass-loss predictions for O and B stars as a function of metallicity
• Grids of stellar models with rotation - I. Models from 0.8 to 120 Msun at solar metallicity (Z = 0.014)
• Core-Collapse Supernovae from 9 to 120 Solar Masses Based on Neutrino-powered Explosions
• Presupernova Evolution of Rotating Massive Stars I: Numerical Method and Evolution of the Internal Stellar Structure
• Black Hole Formation in Failing Core-Collapse Supernovae
• Nucleosynthesis and Remnants in Massive Stars of Solar Metallicity
• Updated stellar yields from Asymptotic Giant Branch models
• Nucleosynthesis and Evolution of Massive Metal-Free Stars
• Modules for Experiments in Stellar Astrophysics (MESA): Time-Dependent Convection, Energy Conservation, Automatic Differentiation, and Infrastructure
• Presupernova evolution and explosive nucleosynthesis of rotating massive stars in the metallicity range -3 <=[Fe/H]<= 0
• The nucleosynthesis of Al26 and Fe60 in solar metallicity stars extending in mass from 11 to 120 Msun: the hydrostatic and explosive contributions
• Stellar evolution with rotation VII: Low metallicity models and the blue to red supergiant ratio in the SMC
• A two-parameter criterion for classifying the explodability of massive stars by the neutrino-driven mechanism
• The Compactness of Presupernova Stellar Cores
• Science with e-ASTROGAM (A space mission for MeV-GeV gamma-ray astrophysics)
• Effects of Rotation on the Minimum Mass of Primordial Progenitors of Pair Instability Supernovae
• SPI observations of the diffuse 60Fe emission in the Galaxy
• Pre-supernova evolution, compact object masses and explosion properties of stripped binary stars
• On Variations Of Pre-Supernova Model Properties
• The 12C + 12C reaction and the impact on nucleosynthesis in massive stars
• Radioactive nuclei from cosmochronology to habitability
• 26Al and 60Fe From Supernova Explosions
• Production of 26Al, 44Ti, and 60Fe in Core-Collapse Supernovae: Sensitivity to the Rates of the Triple Alpha and 12C(a,g)16O Reactions
• Diffuse emission measurement with INTEGRAL/SPI as indirect probe of cosmic-ray electrons and positrons
• New estimates of the contribution of Wolf--Rayet stellar winds to the Galactic 26Al
• Lifetimes of 26Al and 34Cl in an astrophysical plasma
• The Galactic ${}^{26}$Al emission map as revealed by INTEGRAL/SPI
• The presupernova core mass-radius relation of massive stars: understanding its formation and evolution
• Radioactive Al26 and Fe60 in the Milky Way: implications of the RHESSI detection of Fe60
• Gamma-ray Emission of 60Fe and 26Al Radioactivities in our Galaxy
• Nucleosynthesis of binary-stripped stars
• Aluminium-26 from massive binary stars II. Rotating single stars up to core-collapse and their impact on the early Solar System
• Activity measurement of 60Fe through the decay of 60mCo and confirmation of its half-life
• Effective Stellar $\beta$-Decay Rates of Nuclei with Long-lived Isomers: ${}^{26}$Al and ${}^{34}$Cl
• Reducing Uncertainties in the Production of the Gamma Emitting Nuclei 26Al, 44Ti, and 60Fe in Core Collapse Supernovae by Using Effective Helium Burning Rates
• Enhanced production of 60Fe in massive stars
• Gamma-Ray Line Observations with RHESSI