Black holes come in different shapes and sizes. Researchers already know smaller objects are created from dying stars, but supermassive black holes are a different story.
Black holes have such a strong gravitational force that light can't escape, and the supermassive breed can contain masses of up to one billion times that of our own Sun, a California Institute of Technology news release reported.
Researchers believe these supermassive black holes are formed when smaller black holes either take on mass from their environment or merge together.
The problem with this theory is that it does not explain how supermassive black holes could have existed in the early days of the universe because of their extremely slow formation.
One explanation could be "seed black holes," which from early stars.
"In these previous models, there was simply not enough time for any black hole to reach a supermassive scale so soon after the birth of the universe," Christian Reisswig, NASA Einstein Postdoctoral Fellow in Astrophysics at Caltech and the lead author of the study, said. "The growth of black holes to supermassive scales in the young universe seems only possible if the 'seed' mass of the collapsing object was already sufficiently large."
The researchers looked to the theory of supermassive stars, which only existed in the earliest days of the universe. These stars use their own photon radiation to stabilize themselves against gravity. Photon radiation is "the outward flux of photons that is generated due to the star's very high interior temperatures."
The star "pushes gas from the star outward in opposition to the gravitational force that pulls the gas back in. When the two forces are equal, this balance is called hydrostatic equilibrium.
As the supermassive star emits photon radiation it slowly cools, it also becomes more compact and its central density increases. After a few million years the star reaches its maximum compactness, becomes gravitationally unstable, and starts collapsing in on itself to form a black hole.
Researchers once believed that when supermassive black holes collapsed they would flatten out or remain spherical, Reisswig and his team
"This shape is called an axisymmetric configuration. Incorporating the fact that very rapidly spinning stars are prone to tiny perturbations, Reisswig and his colleagues predicted that these perturbations could cause the stars to deviate into non-axisymmetric shapes during the collapse. Such initially tiny perturbations would grow rapidly, ultimately causing the gas inside the collapsing star to clump and to form high-density fragments," the news release reported.
In this scenario, the fragments would orbit the star while gaining density and increasing in temperature. Eventually they would get hot enough to match up "electrons and their antiparticles, or positrons" into "electron-positron pairs." This phenomenon would cause a loss of pressure which would accelerate the collapse. The conditions would cause each fragment to grow so dense that a black hole could form in each one and then merge together to form one supermassive object.
"This is a new finding," Reisswig said. "Nobody has ever predicted that a single collapsing star could produce a pair of black holes that then merge."
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