The James Webb Space Telescope (JWST) has observed a galaxy from an early stage of the universe, revealing that the light from the galaxy J1120+0641 took nearly as long to reach Earth as the universe has existed. This galaxy contains a black hole with a mass exceeding a billion solar masses, a finding that defies current understanding. Published in Nature Astronomy, this discovery challenges previous assumptions about galaxy and black hole formation.
Unexpected findings from JWST Recent studies aimed to uncover an exceptionally efficient feeding mechanism for this black hole but found no such evidence. This suggests that our understanding of galaxy development may be more limited than previously thought. The early cosmic period, less than a billion years after the Big Bang, presents a mystery as young black holes appear unexpectedly massive.
Growth limits of supermassive black holes Galaxies and their central black holes have evolved significantly over the universe’s 13.8-billion-year history. Supermassive black holes grow by consuming gas and merging with other galaxies. However, black hole growth is not limitless due to the pressure exerted by the intense light from their accretion disks, which can hinder further matter accretion. Observations of distant quasars have shown young black holes with masses up to 10 billion solar masses, suggesting rapid early growth that current models struggle to explain.
JWST’s pivotal role The JWST’s mid-infrared instrument, MIRI, has revolutionized the study of distant quasars. In 2019, the MIRI European Consortium allocated observation time to study J1120+0641, then the most distant known quasar. The observations, conducted in January 2023, represent the first mid-infrared study of a quasar from the cosmic dawn, just 770 million years post-Big Bang. The resulting spectrum provides critical insights into the properties of the dust and gas near the black hole.
Surprising normalcy of early quasars The spectrum analysis revealed that the dust torus and feeding mechanisms in this early quasar are similar to those of modern quasars, with only a slightly higher dust temperature. This undermines theories of ultra-efficient early black hole growth and suggests that early quasars were “shockingly normal.” These findings imply that supermassive black holes may have formed with substantial initial masses, possibly from collapsing massive gas clouds, rather than growing rapidly from smaller stellar remnants
Continuing the mystery Dr. Sarah Bosman from the Max Planck Institute for Astronomy, who led the study, notes that these observations support the idea of primordial, large-seeded supermassive black holes. Despite ruling out some explanations, the early quasar’s normalcy in various wavelengths leaves the enigma of how such massive black holes formed so early in cosmic history. The results highlight the need for further investigation into the origins and growth of the universe’s earliest and most massive black holes.
