The discovery of the most distant quasar observed so far, when the Universe was just 690 million years old, is reported in Nature this week. The quasar hosts a supermassive black hole, supporting certain theories of black hole growth in the early Universe.
Quasars are the brightest objects in space, and as such, they enable studies of the early Universe. Their energy is thought to be produced by the growth of a black hole at the centre of a massive galaxy. The location of such distant objects is measured using a unit called redshift, and previously only one quasar has been discovered at a redshift of greater than 7 (ULAS J1120+0641 at a redshift of 7.09).
Eduardo Banados and colleagues report the observations of a quasar at a redshift of 7.54, when the Universe was 690 million years old (just 5% of its current age). They calculate that the quasar, named ULAS J1342+0928, has a black hole with a mass 800 million times greater than that of our Sun. The existence of this supermassive black hole at such an early epoch in the Universe’s history constrains models of early black hole growth.