Discovery of a very metal-poor galaxy overdensity of 17 members near a possible Pop III-enriched absorber at z=5.945, with estimated minimum halo mass of log(M_h,min/M_⊙)=10.68.
The Pristine HeII Emitter near GN-z11: Constraining the Mass Distribution of the First Stars
5 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
The properties of the first metal-free stars remain largely unknown, and so far, the only data-driven constraints on their mass distribution (IMF) come from near-field cosmology. Here, we interpret new observations of the C1 and C2 components of Hebe, the HeII emitter near the galaxy GN-z11. Using a locally calibrated model, we robustly confirm the pristine (PopIII) nature of both components, showing that the measured upper limits on metal lines can only be reproduced by galaxies with $>50\%$ of their stellar mass in PopIII stars. We find that C1 is consistent with a purely PopIII system and adopt a simple parametric approach to infer the implications for the PopIII IMF and stellar mass. The observed $\rm HeII/H_\gamma$ ratio excludes steep IMFs, favoring top-heavy distributions, especially for young stellar ages ($\leq 1$ Myr). Combined with the HeII luminosity, this implies a total PopIII stellar mass of $2 \cdot 10^4 < M_\star/M_\odot < 6 \cdot 10^5$. While degeneracies between IMF, stellar mass, and age remain, adopting the lower stellar masses predicted by simulations ($M_\star < 10^5\,M_\odot$) strengthens the preference for top-heavy IMFs. Combining these results with near-field constraints, which instead exclude the flattest IMFs, we define a data-driven range of viable PopIII IMFs, linking characteristic mass and slope. This work demonstrates that direct observations of high-$z$ PopIII systems can place independent constraints on the IMF of the first stars, opening a new window on their formation and properties.
fields
astro-ph.GA 5years
2026 5representative citing papers
Pixel-by-pixel SBI modeling recovers young massive Pop III clumps at up to 90 percent rate in favorable JWST-like configurations while integrated analyses fail due to contamination.
New stack-based strong-line calibrations from ~1500 spectra yield mass-metallicity relations at z=1-10 with decreasing metallicity toward higher redshift and no slope change, plus 50 EMPG candidates at 1-4% solar metallicity showing large scatter and opposite sSFR trends.
Existing HeII emission-line diagnostics identify pure Pop III galaxies but fail for hybrid Pop III/Pop II systems, introducing spectral degeneracies that hide residual first stars.
Cosmological simulations and SED modeling favor a Pop III star cluster of a few ×10^5 M_sun over an accreting SMBH as the power source for the He II emitter Hebe near GN-z11 at z=10.6.
citing papers explorer
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Possible chemical signatures of first-star enrichment in a very metal-poor galaxy overdensity near the end of reionization
Discovery of a very metal-poor galaxy overdensity of 17 members near a possible Pop III-enriched absorber at z=5.945, with estimated minimum halo mass of log(M_h,min/M_⊙)=10.68.
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A Pixel-by-Pixel Path to Population III Discovery with JWST
Pixel-by-pixel SBI modeling recovers young massive Pop III clumps at up to 90 percent rate in favorable JWST-like configurations while integrated analyses fail due to contamination.
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JADES: the mass-metallicity relation at $z=1-10$. New calibrations, extremely metal-poor galaxies, and chemical diversity
New stack-based strong-line calibrations from ~1500 spectra yield mass-metallicity relations at z=1-10 with decreasing metallicity toward higher redshift and no slope change, plus 50 EMPG candidates at 1-4% solar metallicity showing large scatter and opposite sSFR trends.
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On the detection of Population III galaxies: Emission Line Diagnostics for Hybrid Stellar Populations
Existing HeII emission-line diagnostics identify pure Pop III galaxies but fail for hybrid Pop III/Pop II systems, introducing spectral degeneracies that hide residual first stars.
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What is Powering the Enigmatic He II Emitter Hebe: The First Stars or Black Holes?
Cosmological simulations and SED modeling favor a Pop III star cluster of a few ×10^5 M_sun over an accreting SMBH as the power source for the He II emitter Hebe near GN-z11 at z=10.6.