Our understanding of the universe just got a major boost thanks to the James Webb Space Telescope. Astronomers have discovered the farthest-ever detection of a black hole merger, witnessing this titanic dance in a galaxy system a mere 740 million years after the Big Bang. This finding not only smashes distance records but offers crucial clues about how supermassive black holes grew so enormous in the early universe.
Astronomers had previously observed supermassive black holes in massive galaxies, including our own Milky Way. The sheer size of these black holes hinted at a rapid growth spurt in the early universe, a period shrouded in mystery. The Webb telescope’s observations provide the missing piece.
The newly discovered system, named ZS7, showcases two merging galaxies, each harboring a supermassive black hole. Spectroscopic analysis, only possible with Webb”s incredible resolution, revealed the presence of rapidly moving gas and highly ionized material – signatures of a black hole actively feeding.
“We 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,” explains lead author Hannah Übler of the University of Cambridge in the United Kingdom. “Thanks to the unprecedented sharpness of its imaging capabilities, Webb also allowed our team to spatially separate the two black holes.”
Webb telescope pinpoints the farthest black hole merger ever seen, at just 740 million years after the Big Bang. The discovery reveals two merging galaxies, each harboring a supermassive black hole, and hints at how these giants grew so massive early on. Credits: ESA/Webb, NASA, CSA, J. Dunlop, D. Magee, P. G. Pérez-González, H. Übler, R. Maiolino, et. al
The team estimates one black hole to possess a mass 50 million times that of our sun, with the other likely harboring a similar mass, although shrouded in denser gas. This discovery strengthens the theory that mergers are a key factor in the rapid growth of black holes during the cosmic dawn.
“Our findings suggest that merging is an important route through which black holes can rapidly grow, even at cosmic dawn,” Übler explains. “Together with other Webb findings of active, massive black holes in the distant Universe, our results also show that massive black holes have been shaping the evolution of galaxies from the very beginning.”
Credits: ESA/Webb, NASA, CSA, J. Dunlop, D. Magee, P. G. Pérez-González, H. Übler, R. Maiolino, et. al
The study also paves the way for future gravitational wave discoveries. When these black holes finally merge, they”ll unleash ripples in spacetime detectable by the next generation of observatories, like the Laser Interferometer Space Antenna (LISA).
“Webb”s results are telling us that lighter systems detectable by LISA should be far more frequent than previously assumed,” shared LISA Lead Project Scientist Nora Luetzgendorf of the European Space Agency in the Netherlands. “It will most likely make us adjust our models for LISA rates in this mass range. This is just the tip of the iceberg.”
This groundbreaking discovery is just the beginning. The research team has secured further observation time with Webb, allowing them to delve deeper into the connection between black holes and their early universe galaxies. This includes systematically searching for and characterizing black hole mergers, ultimately revealing the frequency of these events and their impact on black hole growth and gravitational wave production in the young universe.
[via ESA]
