Abundance analysis of 84 type-2 AGNs finds oversolar He and subsolar O at z>2.8, including one object at z=6.26 with record He abundance of 12+log(He/H)=11.64, plus marginal trends of declining He/H and rising O/H toward z=0.
Reevaluating Old Stellar Populations
4 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
Determining the properties of old stellar populations (those with age >1 Gyr) has long involved the comparison of their integrated light, either in the form of photometry or spectroscopic indexes, with empirical or synthetic templates. Here we reevaluate the properties of old stellar populations using a new set of stellar population synthesis models, designed to incorporate the effects of binary stellar evolution pathways as a function of stellar mass and age. We find that single-aged stellar population models incorporating binary stars, as well as new stellar evolution and atmosphere models, can reproduce the colours and spectral indices observed in both globular clusters and quiescent galaxies. The best fitting model populations are often younger than those derived from older spectral synthesis models, and may also lie at slightly higher metallicities.
years
2026 4verdicts
UNVERDICTED 4representative citing papers
Lumina runs a 500 cMpc radiation-hydrodynamic simulation combining IllustrisTNG galaxy formation with six-bin M1 radiation transport to predict late stellar-driven HI reionization ending around z=4.75 and AGN-driven HeII reionization nearly complete by z=3.
Chandra and spectroscopic observations of AzV 493 produce an X-ray luminosity upper limit of <2.5e33 erg/s and inconclusive RV variations, leaving binarity unconfirmed.
The Lumina simulation shows that explicit light-cone integrations produce a CMB optical depth 7% higher than volume-weighted ionization histories, with the excess accumulating near redshift 8 and mass-weighted estimates capturing most of the difference.
citing papers explorer
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Cosmic evolution of the helium and oxygen abundances in type 2 Active Galactic Nuclei: Helium-loud AGNs
Abundance analysis of 84 type-2 AGNs finds oversolar He and subsolar O at z>2.8, including one object at z=6.26 with record He abundance of 12+log(He/H)=11.64, plus marginal trends of declining He/H and rising O/H toward z=0.
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Introducing the Lumina project: large-volume radiation-hydrodynamic simulations of the epochs of hydrogen and helium reionization
Lumina runs a 500 cMpc radiation-hydrodynamic simulation combining IllustrisTNG galaxy formation with six-bin M1 radiation transport to predict late stellar-driven HI reionization ending around z=4.75 and AGN-driven HeII reionization nearly complete by z=3.
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Constraints on Binarity for the Extreme Oe Variable Star AzV 493
Chandra and spectroscopic observations of AzV 493 produce an X-ray luminosity upper limit of <2.5e33 erg/s and inconclusive RV variations, leaving binarity unconfirmed.
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The Lumina Project: CMB Optical Depth Fluctuations from Patchy Reionization
The Lumina simulation shows that explicit light-cone integrations produce a CMB optical depth 7% higher than volume-weighted ionization histories, with the excess accumulating near redshift 8 and mass-weighted estimates capturing most of the difference.