JWST spectra reveal that two z~7 galaxies already show near-solar iron-to-silicon ratios with no strong odd-even effect, favoring early Type Ia supernovae over pair-instability supernovae as the source of iron enrichment.
Nucleosynthesis in Chandrasekhar Mass Models for Type Ia Supernovae and Constraints on Progenitor Systems and Burning-Front Propagation
4 Pith papers cite this work. Polarity classification is still indexing.
abstract
We calculate explosive nucleosynthesis in Chandrasekhar mass models for Type Ia Supernovae(SNe Ia) to obtain new constraints on the rate of matter accretion onto the progenitor white dwarf and on the ignition density of central carbon deflagration. The calculated abundance of the Fe-group neutron-rich nuclei is highly sensitive to the electron captures taking place in the central layers. The yields obtained from a slow central deflagration, and from a fast deflagration or delayed detonation in the outer layers, are combined and put to comparison with solar isotopic abundances. We found that (1) to avoid too large ratios of $^{54}$Cr/$^{56}$Fe and $^{50}$Ti/$^{56}$Fe, the ignition density should be as low as \ltsim 2 \e9 \gmc, and that (2) to avoid the overproduction of $^{58}$Ni and $^{54}$Fe, either the flame speed should not exceed a few % of the sound speed in the central low $Y_e$ layers, or the progenitor star has to be metal-poor compared with solar. Such low central densities can be realized by a rapid accretion as fast as $\dot M$ \gtsim 1 $\times$ 10$^{-7}$M$_\odot$ yr$^{-1}$. In order to reproduce the solar abundance of $^{48}$Ca, one also needs progenitor systems that undergo ignition at higher densities. We also found that the total amount of $^{56}$Ni, the Si-Ca/Fe ratio, and the abundance of elements like Mn and Cr (incomplete Si-burning ashes), depend on the density of the deflagration-detonation transition in delayed detonations. Our nucleosynthesis results favor transition densities slightly below 2.2$\times 10^7$ g cm$^{-3}$.
citation-role summary
citation-polarity summary
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astro-ph.GA 4years
2026 4roles
background 1polarities
unclear 1representative citing papers
A multiphase ISM grain-size model with low supernova dust yield reproduces observed dust-to-stellar mass ratios and UV luminosity functions at z=7-12 by letting small grains seed rapid metal accretion.
The paper identifies underproduction of oxygen in low-mass simulated dwarf galaxies as the likely cause of missing OVI in the CGM, based on comparisons across two simulation suites.
Rotating massive-star yields at 300 km/s improve agreement with metal-poor Sc, Ti, V abundances in one-zone GCE models, with IMF slope variations providing secondary modulation.
citing papers explorer
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JWST Absorption-Line Analysis of UV-Bright Galaxies at $z=7.2-10.6$: Early Chemical Enrichment Traced by C, O, Mg, Al, Si, and Fe
JWST spectra reveal that two z~7 galaxies already show near-solar iron-to-silicon ratios with no strong odd-even effect, favoring early Type Ia supernovae over pair-instability supernovae as the source of iron enrichment.
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Grain-size evolution and rapid dust growth in high-redshift galaxies
A multiphase ISM grain-size model with low supernova dust yield reproduces observed dust-to-stellar mass ratios and UV luminosity functions at z=7-12 by letting small grains seed rapid metal accretion.
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The Simulated Oxygen Shortage (SOS): Mapping the Missing OVI in Simulated Dwarf Galaxies to Subgrid Physics
The paper identifies underproduction of oxygen in low-mass simulated dwarf galaxies as the likely cause of missing OVI in the CGM, based on comparisons across two simulation suites.
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The Sc, Ti, and V Abundance Discrepancy: Testing High-Mass IMF Variation and Massive-Star Rotation
Rotating massive-star yields at 300 km/s improve agreement with metal-poor Sc, Ti, V abundances in one-zone GCE models, with IMF slope variations providing secondary modulation.