Rare Quasar Pair Merges in the Early Universe, Illuminating Black Hole Growth

Astronomers confirmed a rare, merging quasar pair at z=5.7 (about 1 billion years after the Big Bang) using ALMA, revealing two massive galaxies connected by a tidal bridge; both host galaxies harbor more than 10 billion solar masses and rapid star formation, signaling intense black hole growth during early mergers, which are expected to form a true binary in ~2.1 billion years and may impact the gravitational wave background.