Why were galaxies so active in the early universe? We may be getting close to the answer

image via Space.com

May 4, 2026, 10:00 AM

• •Early universe transitioned from cold/dense to warm/less dense.
• •Early galaxies formed stars at a much faster rate than expected.
• •Low stellar return fraction: stars recycled less material.
• •Rapid gas depletion times in early galaxies indicate intense star formation.
• •James Webb Space Telescope is providing valuable new data.

The early universe, initially cold and dense, underwent a dramatic shift, becoming warm and less dense, which significantly influenced the formation of the first galaxies. New observations from the James Webb Space Telescope and detailed computer simulations reveal that these early galaxies formed stars at an unexpectedly rapid pace, challenging existing models. These galaxies had a surprisingly low stellar return fraction, with new stars forming from fresh gas, and their gas depletion times were incredibly short, indicating intense star formation. This research underscores the need to reassess our understanding of galaxy evolution in the early universe, utilizing advanced tools like the JWST and future radio telescopes to refine our models.

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