In a groundbreaking discovery published in Nature Astronomy, astronomers using NASA’s James Webb Space Telescope (JWST) have identified a rare and dramatic event: a major merger of five galaxies occurring just 800 million years after the Big Bang. This cosmic ensemble, dubbed JWST’s Quintet (JQ), offers an unprecedented glimpse into the chaotic and creative processes that shaped the early Universe.
With their collaborators, astronomers Weida Hu, Casey Papovich, Lu Shen, Justin Spilker, and Justin Cole from the Department of Physics & Astronomy and the George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy report JQ, spanning a compact region only 25 kiloparsecs (kpc) across, contains at least 17 star-forming clumps that are producing stars at a staggering rate of 255 solar masses per year, nearly ten times higher than typical galaxies of the same epoch. This intense starburst activity is likely triggered by the gravitational interactions among the merging galaxies, providing critical insight into how massive galaxies formed and evolved.
They also detected a vast, oxygen-rich gaseous halo surrounding and connecting four of the galaxies. This halo, revealed through Webb’s Near Infrared Camera (NIRCam), includes a luminous bridge of enriched material—direct evidence of merger-induced tidal stripping. Such interactions not only fuel star formation but also disperse metals into the circumgalactic medium, enriching the environment and influencing future galaxy growth.
JWST’s ability to peer into the distant past continues to reshape our understanding of galaxy formation. The discovery of JWST’s Quintet underscores the importance of mergers in driving both structural and chemical evolution in the early universe, offering a vivid snapshot of cosmic transformation in action.
This research was supported by the National Science Foundation (NSF PHY-2309135) and the Space Telescope Science Institute (JWST Go Proposal IDs 1180, 1181, 1210, 1286, 1895, 1963, and 3215).