Overview

• An international team led by University of Southampton astronomers used GRAVITY+, which combines four of the Very Large Telescope’s units in Chile, to probe a quasar about 12 billion light-years away.
• The dynamical measurement puts the black hole at roughly 800 million solar masses, far below earlier estimates derived from locally calibrated scaling relations.
• Researchers observed spiralling hot gas and powerful radiation-driven outflows near the core, indicating non-virial motions that can inflate masses inferred from single-epoch spectra.
• The study, published in Astronomy & Astrophysics, leveraged interferometric precision to locate the gas and track its velocity, with outflows reported at up to about 10,000 km/s.
• The authors say prior methods likely overestimated many early-universe black hole masses, prompting calls to reassess quasar measurements from the cosmic dawn.