Low Metallicity Boosts High-Redshift Superluminous Supernovae Rates by Factor of Three

The study combines JWST and ground-based transient surveys to measure host-galaxy oxygen abundances via strong-line diagnostics. After matching on stellar mass and star-formation rate, the rate enhancement persists at 3.1 sigma, implying reduced wind-driven angular-momentum loss allows more massive progenitors to retain the rapid rotation needed for magnetar or pair-instability engines. This directly ties early-universe metal poverty to the observed excess of luminous transients that dominate the high-redshift luminosity function.

Standard single-star evolution models under-predict the observed rate by 40 percent at z=2-3 unless metallicity-dependent mixing is included; the new data favor a threshold near 0.3 Z_sun below which chemically homogeneous evolution becomes efficient. The result also tightens the link between superluminous events and the production sites of r-process elements before widespread enrichment.

The main limitation is the modest sample above z=2.5 and reliance on strong-line metallicity calibrations that carry 0.2 dex systematic uncertainty. A future 200-event sample with direct T_e metallicities from JWST/NIRSpec would test whether the enhancement saturates or continues to rise at still lower abundances.

If confirmed, the finding revises upward the contribution of superluminous supernovae to cosmic metal dispersal and ionizing-photon budgets in the reionization era, altering models that currently treat these events as rare outliers.