BEIJING, April 8 (Xinhua) — According tomedia reports, supermassive black holes are billions of times larger than the sun, and a recent study suggests that supermassive black holes existed “only” 800 million years old in the universe, and that the universe is 14 billion years old. In astrophysicists’ view, the formation of these cosmic “monsters” in such a short period of time is indeed a nerve-wracking problem.
According to classical theory, supermassive black holes don’t have enough time to develop in the young universe. However, observations suggest that they existed 800 million years after the Big Bang. A new study by SISSA offers new explanations for this interesting question.
There is no doubt that our current knowledge of these objects is very limited.
A new paper offers a possible explanation for this thorny problem. Using an initial model, the study suggests that there was a very fast formation process in the initial stages of the development of supermassive black holes, which scientists had previously thought was relatively slow. The results of the study are mathematical evidence of the possibility of supermassive black holes in the young universe, reconciling the time it takes to develop and the age limits of the universe. Perhaps in the near future, this theory could be confirmed by observations of gravitational wave detectors such as the Einstein Telescope (ET) and the laser interferometry (LISA), and in some basic respects by the current Advanced Laser Interference Gravitational Observatory/Room Sitaway interferometer (Advanced LIGO/Virgo) system.
Cosmic monsters growing up in the center of the galaxy
The researchers’ analysis began with a well-known observational evidence that the growth of supermassive black holes occurred in the central region struck by galaxies. Inside today’s elliptical galaxy, there is a very high gas content, and star formation is very intense. The largest stars have a short lifespan and will soon evolve into stellar black holes, the mass equivalent of dozens of suns; they are small, but they form many in these galaxies, and the dense gas surrounding these black holes has a very powerful dynamic friction altogether that plays a decisive role in causing them to move rapidly to the center of the galaxy. Most black holes that reach the center region merge, creating the “seeds” of supermassive black holes.
According to the classical theory, a supermassive black hole grows at the center of a galaxy, constantly capturing surrounding matter, mainly gas, causing it to “grow” and eventually devour it at a pace proportional to mass. Thus, in the early stages of development, when the mass of a black hole is small, its growth is very slow. According to calculations, reaching the observed mass of the sun is billions of times that it will take a long time, even older than the young universe itself. However, the results of this new study suggest that supermassive black holes may grow much faster than previously thought.
Crazy “Sprint” of the Black Hole
The value calculations show that the dynamic migration and fusion of stellar black holes can enable the seeds of supermassive black holes to reach 10,000 to 100,000 times the mass of the sun in 50 to 100 million years, and from this point forward, the growth of the central black hole will be as rapid as the standard theory holds for the direct acumbeve gas, as the standard theory holds, because the amount of gas it successfully attracts and absorbs will be very large and dominate the proposed process. However, as our mechanism envisages, it is from such a huge “seed” that accelerates the growth of supermassive black holes and makes them form in the young universe. In short, based on this theory, we can say that by the 800 million years after the Big Bang, supermassive black holes might have spread throughout the universe.
Observing the “seeds” of supermassive black holes
In addition to illustrating the model and proving its effectiveness, this paper also proposes a method of testing. “The fusion of numerous stellar black holes with the seeds of supermassive black holes at the center of galaxies produces gravitational waves that we look forward to using current and future detectors to observe and understand them,” the researchers explained. “Researchers are particularly concerned about the very small seeds of black holes at the center of galaxies, the gravitational waves emitted by supermassive black holes at the initial stage. Current detectors such as the advanced LIGO/Virgo system may identify these gravitational waves and be fully described by the future Einstein telescope. The future LISA probe will be launched into space around 2034, which will help to study the subsequent stages of the development of supermassive black holes, and through these observations, “the processes we propose can be validated by future gravitational wave detectors in different stages, in a complementary manner.” “
The study shows how researchers are moving closer to the new frontiers of gravitational waves and multi-messenger astronomy. In particular, the main objective will be to develop theoretical models that, as designed in this case, could provide solutions to unresolved problems in astrophysics, cosmology and basic physics, using information from current and future gravitational wave experiments.