Until Now
Cosmology

The overmassive black hole in UHZ1

470 million years in, a black hole already as heavy as its entire host galaxy.

When
Known to
± 10 million years
Era
Reionisation, Stelliferous

Chandra and JWST together found an X-ray quasar at redshift 10.1 with a black hole of roughly 40 million solar masses — comparable to the whole stellar mass of the galaxy around it, where the modern ratio is closer to a thousandth. Such an object is very hard to grow from a stellar-mass seed in 470 million years, and it is the strongest evidence yet that some black holes formed by the direct collapse of gas clouds.

Just before

Just after