Hubble study finds supernova winds can suppress the light behind cosmic reionization
Using Hubble observations of nearby starburst galaxies as proxies for early galaxies, researchers found that those with the fastest winds let the smallest fraction of ionising radiation escape. The findings, published in Nature Astronomy, suggest radiation escaped before supernova-driven winds formed, challenging the theory that those winds cleared a path during reionisation.
Bottom line — The Hubble findings point to young stars—not later supernova winds—as the early route for ionising light to escape.
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Newswise reports that reionisation began about 13 billion years ago, as radiation from galaxies ionised neutral hydrogen between galaxies.
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The researchers measured escaping light and wind speeds in nearby starburst galaxies, which resemble some galaxies thought to have contributed to early reionisation.
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Stephan McCandliss of Johns Hopkins said supernova energy may increase the coverage of neutral gas and dust, suppressing radiation escape.
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Renyue Cen of Zhejiang University said the findings highlight the need to examine how young stars’ radiation and winds affect gas before the first supernovae.
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