One of the most famous theories of Stephen Hawking dark matter has suffered greatly after publication of the results of the Japanese team of astrophysicists under the guidance of Masahiro Takada the Physical-mathematical Institute of the Universe in Kavli, reports Live Science. Left this world last year, a famous physicist believed that this mysterious and invisible substance consists of primary black holes, which appeared immediately after the Big Bang. Japanese scientists using the Subaru telescope, we conducted an experiment whose results, though not fully refute Hawking’s theory, but admit that these black holes must be really tiny to explain the nature of dark matter.
Dark matter is a term which physicists have dubbed the mysterious substance, which, in their opinion, could explain one interesting fact: in the Universe everything moves and rotates as if it contained more mass than we can detect. Different scientists at different times have tried to attribute the properties of the so-called dark matter in different objects. In the 1970’s, Stephen Hawking and his colleagues suggested that the Big Bang could create a large number of relatively small black holes, each the size of a proton. These tiny celestial bodies are difficult to see, but they will have a strong gravitational influence on other objects — two well-known properties of dark matter.
So far this theory could be tested only on the primary black holes whose mass is more lunar. But with the advancement of technology, scientists were able to obtain more and clearer pictures of outer space. For their new study, a team of Japanese astronomers used the camera Hyper Suprime-Cam (HSC) mounted on Subaru telescope located in Hawaii. With its help, they took pictures of the whole Andromeda, our nearest galaxy, trying to find these small objects. The result of their work published in the journal Nature Astronomy.
Black holes do not emit light, however, supermassive black holes, like the one in the center of the galaxy M87, a photo, where scientists recently gotsurrounded by bright accretion disks of hot matter. But because the primary hole size billions of times smaller and have no visible surrounding luminous matter, you can find them only by watching them created powerful gravitational fields that cause the distortion of radiation to nearby objects. This phenomenon is called microlensing.
Telescopes to find microlens of black holes with extended shooting stars. When black gifts passes in front of the observation point and the star, it bends the light shone, causing him to “break out”. The smaller the black hole, the faster the flash.
“If an object that produces a lens that has, say, one solar mass, the time scale (duration of flash) will range from several months to a year,” explains Masahiro Takada the Physical-mathematical Institute of the Universe in Kavli.
However, the primary holes that were looking for the Japanese team, have only part of this mass – it is approximately equal to the mass of our moon. This means that the observed flash should be much shorter.
Takada calls the HSC camera is unique because with it scientists have been able to obtain images of all the stars in the galaxy of Andromeda with a minimum delay of about 2 minutes. In total, astronomers were able to get about 200 pictures of Andromeda in 7 hours night. In the end they found only one alleged event of microlensing. According to Takada if primary black holes account for a significant fraction of dark matter, they had to see about 1000 microlensing signals.
“Microlensing is the gold standard of technology to search for black holes,” says physicist Simeon Byrd from the University of California engaged in the study of black holes, but did not participate in recent study.
“The work of Japanese scientists allows to exclude primary black holes as the main source of dark matter.”
Does this mean that the theory Hawking has been completely refuted? Takada and bird not in a hurry with final conclusions. According to them, the results still cannot fully exclude the existence of primary black holes, because of their small mass, flash their signals would be too short to have time to fix them. According to the researchers, it is necessary to develop new tools that would allow them to detect.
At the same time, scientists say that the discovery of even one such signal may be critical to subsequent studies that will be a revolutionary test some of the theories of Hawking.
“Only one monitored us in something to convince. You will need to conduct. If this signal was indeed a signal of the primary black hole, we must continue the search for her relatives,” concludes Takada.