Astronomers, utilizing the James Webb Space Telescope (JWST), have made a groundbreaking discovery: the most distant massive quiescent galaxy (MQG) ever observed, named RUBIES-UDS-QG-z7. This galaxy's light has journeyed for 13 billion years, offering a glimpse into its existence just 700 million years after the Big Bang. This finding challenges established models of galaxy evolution, suggesting that some galaxies ceased star formation much earlier than previously theorized.
RUBIES-UDS-QG-z7 rapidly formed stars, amassing a mass equivalent to 10 billion suns, before abruptly halting star formation. This challenges existing models that predicted significantly fewer such galaxies in the early universe. The galaxy's swift and efficient star formation, followed by its early quenching, indicates that the processes governing star formation in the early universe may require a significant reevaluation.
Unlike other early galaxies observed by JWST, RUBIES-UDS-QG-z7 shows no evidence of an active galactic nucleus (AGN), implying that its light originates solely from stars. While current estimates suggest such galaxies are rare, further investigation is needed. Future JWST observations, including high-resolution spectroscopy, along with data from the ALMA telescope, are planned to further investigate RUBIES-UDS-QG-z7's composition and formation history. This discovery provides valuable insights into the formation and evolution of galaxies in the early universe, paving the way for a deeper understanding of cosmic history.