Farthest and oldest black hole collision ever observed by James Webb Space Telescope (JWST)

The James Webb Space Telescope (JWST) has enabled astronomers to identify the most distant merger between supermassive black holes ever observed. The colliding black holes are situated at the heart of merging galaxies that are so distant that the collision is seen as it was happening just 740 million years after the Big Bang, when the universe was a fraction of its current age.

For some time, astronomers have postulated that supermassive black holes with masses millions or even billions of times that of the sun, which are found at the heart of most large galaxies, have been responsible for driving cosmic evolution. This new JWST finding indicates that supermassive black holes have been in the driving seat almost since the beginning of time.

The JWST has been regularly uncovering supermassive black holes in the infant universe, which has been a problem because the merger process that facilitates their growth should take periods in excess of a billion years. These results could also help solve the troubling mystery of how supermassive black holes grew to tremendous masses so early in the history of the universe.

“Our findings suggest that merging is an important route through which black holes can rapidly grow, even at cosmic dawn,” stated research leader and University of Cambridge scientist Hannah Übler in a press release. “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.”

These electromagnetic emissions feature characteristic features that allow astronomers to determine they originate from feeding supermassive black holes. These features can only be determined by telescopes in orbit around the Earth. To observe them in the most distant quasars, the extremely powerful and sensitive infrared eye of the JWST is required.

To investigate the merging of quasars in the early universe, the research team led by Übler focused their attention on a galactic system approximately 12 billion light-years away, designated as ZS7. They employed the Near-InfraRed Spectrograph (NIRSpec) on the James Webb Space Telescope (JWST) to conduct their observations.

“Our findings indicate the presence of exceedingly dense gas exhibiting rapid motions in the vicinity of the black hole, in addition to hot and highly ionized gas illuminated by the energetic radiation typically produced by black holes during their accretion episodes,” explained Übler. “The JWST’s exceptional imaging capabilities enabled our team to spatially separate the two black holes.”

The team estimated that one of the supermassive black holes involved in this merger had a mass equivalent to approximately 50 million suns. While they hypothesize that the second supermassive black hole has a similar mass, the scientists were unable to confirm this due to the presence of dense gas surrounding it.

“The stellar mass of the system under study is comparable to that of our neighboring galaxy, the Large Magellanic Cloud,” stated Pablo G. Pérez-González, a scientist from the Centro de Astrobiología (CAB). “One can attempt to conceptualize the potential impact of merging galaxies on their evolution if each galaxy possessed a supermassive black hole of comparable or greater magnitude than the one observed in the Milky Way.”

Upon the eventual merger of the two supermassive black holes, the resulting gravitational waves would have set the very fabric of space ringing with tiny ripples. These waves would radiate outward from the collision at the speed of light and could possibly be detected by the next generation of gravitational wave detectors.

This could include the first space-based system, the Laser Interferometer Space Antenna (LISA), an arrangement of three spacecraft being developed by NASA and the European Space Agency (ESA) and scheduled for launch in 2035.

“The JWST’s results indicate that lighter systems detectable by LISA should be far more frequent than previously assumed,” stated Nora Luetzgendorf, the ESA’s Lead Project Scientist for LISA. “It will most likely necessitate adjustments to our models for LISA rates in this mass range. This is merely the beginning.”

Even before the launch of LISA, the JWST will continue to investigate early supermassive black holes. A program in the third cycle of operations for the $10 billion telescope will commence this summer. This program will examine the relationship between massive black holes and their host galaxies in the first billion years after the Big Bang. This will include searching for and characterizing mergers.
This could inform scientists as to the rate at which supermassive black holes collide and whether this is sufficient to explain their rapid growth in the early universe.

The original article and photos are available at space.com