Hubble: Supernova Winds Hinder, Not Help, Early Universe Reionization

Hubble observations of nearby starburst galaxies show that supernova-driven winds do not clear paths for ionizing radiation but instead increase the coverage of neutral gas and dust. Galaxies with the fastest winds let the smallest fraction of ionizing radiation escape, challenging the leading explanation for reionization.

• Galaxies with the fastest winds allow the smallest fraction of ionizing radiation to escape
• Supernova winds increase, rather than decrease, neutral gas and dust coverage
• Radiation likely escapes before galactic winds form, driven by young stars
• The findings, published in Nature Astronomy, call for revised cosmological simulations