Webb witnesses black hole merger near the beginning of time

A long time ago, two massive black holes merged in two galaxies far, far away. This happened when the universe was just 740 million years old. A team of astronomers used JWST to study this event. This event is the most distant (and earliest) discovery of a black hole merger. Such collisions are very common in recent times in the universe’s history, and astronomers know that they cause increasingly massive black holes at the centers of galaxies. The resulting supermassive black hole could contain millions of solar masses. They influence the evolution of galaxies in many ways. Astronomers have used JWST and HST to discover supermassive black holes earlier in cosmic time, within the first billion years of the universe’s history. A question arises here. How were they able to get so huge so quickly? Black holes accumulate matter as they grow, and for the most massive holes, colliding galaxies are part of the story of matter extraction.

What JWST showed about early black hole mergers His latest JWST observations focused on a system called ZS7. This is a galactic merger that brings together two very early systems containing colliding black holes. This is something astronomers cannot detect using ground-based telescopes. The merger itself is still a long way off. Furthermore, the expansion of the universe extends its light into the infrared region of the electromagnetic spectrum. Therefore, it is no longer accessible from the ground. However, infrared light can be detected using JWST’s near-infrared spectrometer (NIRSpec). According to astronomer Hannah Obler of the University of Cambridge in the UK, this could be used to find traces of mergers in the early universe. “We found evidence of very dense, fast-moving gas near the black hole, and at high temperatures and altitudes illuminated by the high-energy radiation typically produced when black holes accrete. “We found evidence of ionized gas,” leader Brell said. Author of article about this discovery. “Thanks to his unprecedented sharp imaging capabilities, Webb also enabled our team to spatially separate his two black holes.” These black holes are so massive that each black hole contains about 50 million solar masses. The other probably has about the same mass, but is hard to tell because it is embedded in a region of dense gas. Based on their stellar masses, these galaxies belong to roughly the same stellar mass population as the nearby Large Magellanic Cloud in Spain, according to astronomer Pablo G. Pérez González of the CSIC/INTA Center for Astrobiology (CAB). Masu. “If every galaxy had a supermassive black hole as large or larger than the one in the Milky Way, you can imagine how the merging evolution of galaxies would be affected.” Further implications of black hole mergers in the Cosmic Dawn Analysis of JWST observations strengthens the idea that mergers are an important pathway for black hole growth. According to Oehler, this is especially true for the early universe: “Together with other Webb results on active massive black holes in the distant universe, our results also show that massive black holes have been shaping galaxy evolution from the very beginning.” Many of the very early active galactic nuclei (AGN) in the universe are associated with relatively massive black holes. These are probably part of a general merging process in the early epoch. Astronomers would like to know when these mergers started, which would help determine the growth of the central supermassive black holes. This type of merger could be a pathway for black holes to grow very early in cosmic time.

That’s why astronomers are eager to discover them using JWST and future telescopes. They are key to understanding the evolution of galaxies and black holes in the early universe. “Our results seem to support a scenario of imminent massive black hole mergers in the early universe, which could have triggered the initial growth of black holes,” Wooler and his team wrote in their paper. “We emphasize that this is an additional important pathway for This, along with other discoveries in the recent literature, suggests that massive black hole mergers are common in the distant Universe. Of course, these mergers do more than just produce light that can be detected by JWST. It also produces very weak gravitational waves. But the upcoming Laser Interferometer Space Antenna (LISA) may be able to detect these waves. It will be installed in the 2030s and will allow JWST to focus on the types of galaxy-black hole mergers it currently detects in the infrared.

source: https://academic.oup.com/mnras/article/531/1/355/7671512?login=false