ALMA and VLA Reveal a Vast Reservoir of Star-Forming Fuel in a Galaxy Near Cosmic Dawn

Scientific Paper Highlights Astronomers used ALMA and the NSF Very Large Array (VLA) to detect molecular gas in REBELS-25, a massive star-forming galaxy observed just 700 million years after the Big Bang. The observations reveal a reservoir of roughly 100 billion solar masses of cool gas — the raw fuel for star formation — in one of the earliest and most distant galaxies ever studied in this way. The VLA achieved the most distant detection to date of a key molecular gas tracer, while ALMA provided a detailed picture of the galaxy’s star-forming environment. Astronomers have directly detected a vast reservoir of cool molecular gas in REBELS-25, a massive star-forming galaxy seen just 700 million years after the Big Bang. The discovery, made using the NSF Very Large Array (VLA) and the Atacama Large Millimeter/submillimeter Array (ALMA), provides a rare direct measurement of the star-forming fuel available to a galaxy in the early universe.