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from the why-did-the-quasar-cross-the-event-horizon dept.
Quasars are the brightest objects in the universe, and are powered by supermassive black holes capturing matter and simultaneously accelerating particles away from them at near the speed of light. Many quasars, however, date back to the first 800 million years of the universe, long before stars were old enough to collapse, explode in a supernova, and form said supermassive black holes.
Researchers have now modeled the creation of these early black holes sans explosion.
...black holes in the very early universe could have formed by simply accumulating a gargantuan amount of gas into one gravitationally bound cloud. The researchers found that, in a few hundred million years, a sufficiently large such cloud could collapse under its own mass and create a small black hole — no supernova required.
These theoretical objects are known as direct collapse black holes (DCBHs). According to black hole expert Shantanu Basu, lead author of the new study and an astrophysicist at Western University in London, Ontario, one of the defining features of DCBHs is that they must have formed very, very quickly within a very brief time period in the early universe.
The process involves an interaction of two nearby galaxies, one over-actively forming new stars and the other highly gaseous but relatively inactive in star formation.
As new stars form in the busy galaxy, they blast out a constant stream of hot radiation that washes over the neighboring galaxy, preventing the gas there from coalescing into stars of its own. Within a few hundred million years, that starless gas cloud could accrete so much matter that it simply collapses under its own weight, forming a black hole without ever producing a star, Basu found.
According to Basu, black holes that formed at the beginning of that initial 150 Million year window would have grown rapidly, potentially increasing their mass by as much as a factor of 10,000.
Journal Referrence
Shantanu Basu and Arpan Das 2019 ApJL 879 L3 DOI:https://doi.org/10.3847/2041-8213/ab2646
(Score: 3, Interesting) by Anonymous Coward on Monday July 08 2019, @05:38PM
We don't know if those quantum black holes exist or not. They are sometimes called Planck particles because they have the Planck mass and their Schwarzschild radius is the Planck length. (Unusually for a Planck unit, the Planck mass is human-comprehensible, about the mass of a small speck of dust).
Physics occurring on this time scale are completely unknown. It is not possible for an object this massive to pop into existence on longer timescales, so it's not possible to seriously claim that this happens as Hitchens' Razor applies. If these particles/black holes exist in a meaningful way, it's because they are stable and some process has produced them. The existence of any kind of quantum foam has yet to be experimentally confirmed, much less at very large masses.
As for direct collapse of a stellar core into a black hole without a supernova, the star cited in the paper is only 25 solar masses, which is "ordinary" (by the standards of supernovae!) It's not absolutely certain that the star did this, but if it did, it must be because of some unknown conditions or stellar core process and not due to extreme mass. A 25 solar mass gas cloud will always form a normal star. Hypothetical direct collapse black holes from gas clouds would need at least an order of magnitude more mass.