James Webb Unveils Galaxy‑Killing Wind That Could Foretell the Milky Way’s Demise

Galaxy‑Killing Wind Observed in Early‑Universe Merger

James Webb Space Telescope has captured a massive outflow of gas from the galaxy merger CRISTAL‑02, located just one billion years after the Big Bang. The phenomenon, described by researchers as a galaxy‑killing wind, is blowing material away at speeds exceeding 300 km s⁻¹. CRISTAL‑02 contains roughly ↑ 10 billion solar masses in stars and is spawning new stars at a rate of ↑ 260 M☉ yr⁻¹, three times the norm for similar systems. At the same time, it is losing gas at ↓ 500 M☉ yr⁻¹, enough to exhaust its fuel in less than 100 million years. The outflow, amounting to 1.5 billion solar masses, appears powered by intense stellar winds and supernova explosions triggered by the collision.

“The wind is ejecting material twice as fast as the galaxy forms stars,” said lead author Rebecca Davies of Swinburne University.

Co‑author Andreas Faisst of Caltech noted that if the outflow persists, the galaxy will become quiescent almost instantly on cosmic timescales. This observation offers a tangible example of how star‑driven feedback can shut down star formation in the early universe, a process previously inferred but never seen directly. Comparisons with 99 analogous outflows spanning 12 billion years show that feedback efficiency has stayed roughly constant, challenging models that favor black‑hole‑driven winds. The findings also echo predictions for the future Milky Way‑Andromeda merger, where a similar starburst could generate a wind that ultimately quenches star formation, leaving a massive elliptical galaxy. For broader context see Reuters and NASA.

Words by Nova Stirling (Aerospace & Space Tech Correspondent).