THE ORIGIN OF MYSTERIOUS ULTRAMASSIVE BLACK HOLES

SUBSCRIBE TO SPACE TODAY PLUS NOW AND GET ACCESS TO HUNDREDS OF NEW CONTENT IN PORTUGUESE ABOUT ASTRONOMY AND ASTRONAUTICS FOR ONLY R$29.90 PER MONTH!!! https://quero.plus LISTEN TO THE EVENTS HORIZON PODCAST: https://www.spreaker.com/episode/5244... Ultramassive black holes are the most massive objects in the universe. Their mass can reach millions and billions of solar masses. Supercomputer simulations on TACC's Frontera supercomputer have helped astrophysicists reveal the origin of ultramassive black holes formed about 11 billion years ago. “We found that one possible formation channel for ultramassive black holes is the extreme merger of massive galaxies that likely occurs around the time of ‘cosmic noon,’” said Yueying Ni, a postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics. Ni is the lead author of a paper published in The Astrophysical Journal (December 2022) that found the formation of ultramassive black holes from the merger of triple quasars, systems of three galactic nuclei illuminated by gas and dust falling into a nested supermassive black hole. Working hand in hand with telescope data, computer simulations help astrophysicists fill in missing pieces about the origins of stars and exotic objects like black holes. One of the largest cosmological simulations to date is called Astrid, co-developed by Ni. It is the largest simulation in terms of particle, or memory, capacity in the field of galaxy formation simulations. “The scientific goal of Astrid is to study galaxy formation, supermassive black hole coalescence, and reionization throughout cosmic history,” she explained. Astrid models large volumes of the cosmos spanning hundreds of millions of light-years, but can zoom in to very high resolution. Ni developed Astrid using the Frontera supercomputer at the Texas Advanced Computing Center (TACC), the most powerful academic supercomputer in the United States, funded by the National Science Foundation (NSF). “Frontera is the only system we’ve run Astrid on since day one. It’s a pure Frontera-based simulation,” Ni continued. Frontera is ideal for Ni’s Astrid simulations because of its ability to support large applications that require thousands of compute nodes, the individual physical systems of processors and memory that are harnessed together for some of the most difficult calculations in science. “We used 2,048 nodes, the maximum allowed in the large queue, to routinely run this simulation. This is only possible on large supercomputers like Frontera,” Ni said. Their findings from the Astrid simulations show something completely incomprehensible – that black hole formation can reach a theoretical upper limit of 10 billion solar masses. “This is a very challenging computational task. But you can only capture these rare and extreme objects with a large-volume simulation,” Ni said. “At this epoch, we saw an extreme and relatively rapid merger of three massive galaxies,” Ni said. “Each of the galaxy masses is 10 times the mass of our own Milky Way, and a supermassive black hole sits at the center of each galaxy, after which these triplets interact gravitationally and merge with each other.” In addition, new observations of galaxies at cosmic noon will help unravel the coalescence of supermassive black holes and the formation of ultramassive ones. Data are now arriving from the James Webb Space Telescope (JWST), with high-resolution details of the galaxy morphologies. “We are looking to model observations for JWST data from the Astrid simulation,” Ni said. “In addition, NASA’s upcoming Laser Interferometer Space Antenna (LISA) gravitational-wave observatory will give us a much better understanding of how these massive black holes merge and/or coalesce, along with the hierarchical structure, formation, and galaxy mergers throughout cosmic history,” he added. “This is an exciting time for astrophysicists, and it is great that we now have simulations to enable theoretical predictions for these observations.” Ni’s research group is also planning a systematic study of AGN hosting in galaxies in general. “They are a very important science target for JWST, determining the morphology of AGN host galaxies and how they differ compared to the broader galaxy population during cosmic noon,” she added. “It’s great to have access to supercomputer technology that allows us to model a patch of the universe in great detail and make predictions from the observations.” SOURCES: https://www.tacc.utexas.edu/-/rare-qu... https://iopscience.iop.org/article/10... #BLACKHOLE #UNIVERSE #LIFE