Pan of ZS7 environment

This image shows the environment of the galaxy system ZS7 from the JWST PRIMER programme (PI: J. Dunlop) as seen by Webb's NIRCam instrument.

New research using the NIRSpec instrument on the NASA/ESA/CSA James Webb Space Telescope has determined the system to be evidence of an ongoing merger of two galaxies and their massive black holes when the Universe was only 740 million years old. This marks the most distant detection of a black hole merger ever obtained and the first time that this phenomenon has been detected so early in the Universe. 

The team has found evidence for very dense gas with fast motions in the vicinity of the black hole, as well as hot and highly ionised gas illuminated by the energetic radiation typically produced by black holes in their accretion episodes. Webb also allowed the team to spatially separate the two black holes and determined that one of the two black holes has a mass that is 50 million times the mass of the Sun. The mass of the other black hole is likely similar, although it is harder to measure because this second black hole is buried in dense gas.