Ultra-Massive Black Holes: How Does the Universe Produce Objects So Massive?



The largest things in the universe that we are aware of are black holes. Ultra-massive black holes, not star mass black holes or supermassive black holes (SMBHs) (UMBHs.) Similar to SMBHs, UMBHs are found at the galactic core, but they possess an astonishingly enormous quantity of mass—more than five billion solar masses. Phoenix A, a UMBH with up to 100 billion solar masses, is the biggest black hole we are aware of.

How is it that something can get so big?

UMBHs are uncommon and illusive, and it is unknown where they came from. A program was used by a group of astrophysicists investigating the issue to shed light on how these enormous things came to be. They located the 'Cosmic Noon' of the Universe, roughly 10 to 11 billion years ago, as the beginning of UMBH.

"Ultramassive Black Holes Created by Triple Pulsar Mergers at z = 2" is the title of their article, which appeared in The Astrophysical Journal Letters. Yueying Ni, a postdoctoral associate at the Center for Astrophysics/Harvard & Smithsonian, is the primary author.

We discovered that one potential source of ultra-massive black hole creation is the extreme merging of massive galaxies, which is most likely to occur during the 'cosmic noon,' according to Ni.

UMBHs are incredibly uncommon. It takes a huge, intricate computer to produce them in scientific models. Astrid steps in at this point. Running on the Frontera supercomputer at the University of Texas, Austin, it is a sizable cosmic hydrodynamical model. Large-scale models performed by Astrid can monitor variables such as neutral hydrogen, temperature, metallicity, and dark matter. Astrid is at the top of the list of models similar to her in terms of the quantity of elements it contains.


Lead author Ni stated in a news statement that the scientific purpose of Astrid is to investigate galaxy formation, the coalescence of supermassive black holes, and re-ionization throughout cosmic history. (Ni is one of Astrid's co-creators.) A strong supercomputer is required for a potent instrument like Astrid. Fortunately, UT Austin is home to the nation's most potent research machine. Frontera is the only method we have used since Astrid's inception. It's a game that is entirely Frontera-based, she said.

It is well known that galaxies expand in size through collisions, and it is probable that SMBHs do the same. However, UMBHs are much uncommon and even more enormous. How are they created?

Working with Astrid provided a solution for the team.

The cosmic noon, which occurred 11 billion years ago and is when star formation, active galactic nuclei (AGN), and supermassive black holes in general achieve their highest activity, is when we discovered three ultra-massive black holes, according to Ni.



A significant moment in the annals of the Cosmos is Cosmic Noon. According to astronomers, this time era saw the birth of half of all stars. Redshift z=2 to z=3, or when the Universe was roughly 2 to 3 billion years old, correlates to this. At that time, massive amounts of gas were flowing into galaxies from the cosmic medium. During cosmic midday, galaxies formed about half of their star mass. So it comes as no surprise that they discovered three UMBHs that gathered their mass at cosmic midday, as Ni claims.

"We observed an extreme and comparatively quick merging of three massive galaxies in this era," Ni said. "A supermassive black hole is located in the core of each galaxy, and each galaxy is 10 times as big as our own Milky Way. Our results indicate the potential that these quasar triplet systems, which gravitationally engage and merge, are the origin of those uncommon ultra-massive blackholes.

The term Quasars is deceptive. Although the term dates back to a period before astronomers understood what they were, it refers to a quasi-stellar object. Although they are a subgroup of active galactic centers, quasars are incredibly bright. All of the material that enters the SMBH at a galaxy's core contributes to its brightness. The simulation shows that chances for triple quasar systems to combine and create UMBHs are decreasing.



The post-merger UMBH is getting close to the theoretical maximum mass limit for black holes, which is about 50 billion solar masses. The Astrid scenario "... is not a prescription for a new upper bound for the black hole mass," the experts point out. This is so because models, even one as sophisticated as Astrid, are unable to fully capture the specifics of black hole accretion processes at sizes smaller than kiloparsec. After all, Astrid is a sizable prototype.

UMBHs of the same magnitude as the one in the simulation could, however, be found in huge galaxy clusters in the nearby Universe if the simulation is accurate. If so, they probably also put together their mass through galaxy/BH collisions during cosmic midday.

The authors write in their article, "We discover that multiple massive galaxy mergers, which are extremely uncommon events that occur around z 2, the epoch when both star formation and AGN achieve their peak activity, can produce ultramassive black holes with extreme masses of 50 billion solar masses>.

Better data are required to support these results. The JWST has already made strides in its mission to explore the early Cosmos and solve some of its riddles. According to Ni, the JWST will benefit from the team's efforts with Astrid. Ni stated, "We're seeking an observational mock-up for JWST data from the Astrid scenario.

Future observatories, particularly NASA's LISA space array, will be helpful.

Furthermore, Ni added, "the future space-based NASA Laser Interferometer Space Antenna (LISA) gravitational wave observatory will give us a much better understanding of how these massive black holes merge and/or coalescence, as well as the hierarchical structure, formation, and galaxy mergers along the cosmic history. "Astrophysicists are living in an exciting moment, and it's fortunate that simulation can enable theoretical forecasts for those findings,"