Caught: The Light That Lit Up the Young Universe ⚡ экспресс
The study reports the first direct detection of ionizing photons at rest-frame wavelengths of 350 Å, 392 Å, and 485 Å from a sample of Lyα emitters at redshift z ≈ 5.9–6.0. The data were obtained through deep UV observations with AstroSat and HST, followed by spectroscopic confirmation with VLT/MUSE and JWST/NIRSpec. The stacked spectrum (absolute UV magnitude M_UV ≈ −18.77, ~0.1 L*) reveals a hard slope of −2.3 ± 0.1, a true ionizing efficiency of log₁₀ ξ_ion^true = 25.86 ± 0.02 Hz erg⁻¹, and an escape fraction f_esc ≈ 0.8. Individual estimates indicate very blue UV continua (β ≤ −3) for three galaxies, ages under 6 million years for four, and low metallicity (0.02–0.05 Z_⊙) for two. The results point to the presence of massive hot stars capable of driving cosmic reionization and suggest the onset of HeI reionization by this epoch (energies >24.6 eV).
After the Big Bang, the Universe was filled with cold gas—mostly neutral hydrogen and helium. It enveloped the cosmos like a morning fog, impenetrable to light. The Dark Ages began.
When the first galaxies ignited, their radiation, like a searchlight beam, started knocking electrons out of atoms. This process—reionization—gradually dispersed the fog, making space transparent.
For the first time, astronomers have directly detected that very cleansing light. The James Webb Space Telescope and other instruments studied galaxies seen a billion years after the Big Bang. Spectrum analysis revealed: nearly 80% of ultraviolet light burst out—far more than models predicted. But the main surprise—some photons carried energy above 24.6 electron volts, enough to strip electrons even from helium. Previously, this was thought possible only at later stages. So the first stars were true titans, and their light was sufficient to clear the fog even from the most stubborn atoms.
🎯 The most energetic photons had energies above 24.6 electron volts—enough to strip electrons even from helium. Previously, this was thought to have happened much later.
🎬 In the series "Firefly," the ship "Serenity" flies through worlds aglow with the light of many suns. Astronomers, however, have captured that ancient light that ignited those suns.