As astronomical observations show, ordinary matter that we can touch or see constitutes only 5% of the total mass and energy of the entire Universe. In our galaxy, per 1 kilogram of matter contained in stars, there are 15 kilograms of 'dark matter' - which does not shine and interacts only through gravity.
"Our research has ruled out one of the theses about the nature of 'dark matter', but modern science still does not know the answer to the question of what it actually is" - said one of the research team members: Radosław Poleski, PhD.
"Neither astronomers nor physicists can understand what dark matter actually is. We see its influence, we see that there is more matter than what produces light. The result of our research is that dark matter is not isolated black holes" - the scientist continued.
The research was conducted by a team of scientists working as part of the OGLE (Optical Gravitational Lensing Experiment) program conducted by Warsaw University's Astronomical Observatory. They involved observing specific phenomena in the Large Magellanic Cloud galaxy.
"If dark matter consisted of black holes, we should observe phenomena called gravitational microlensing. Over the twenty years of our research, we have observed very few such phenomena. If black holes constituted a significant percentage of dark matter, there would be hundreds of such phenomena" - Radoslaw Poleski explained.
The Polish research results were presented in two publications - "Nature", and "Astrophysical Journal Supplement Series", both of which are among World's most prestigious scientific journals. The studies include calculations demonstrating that black holes of 10 solar masses may comprise 1.2% of dark matter at most, 100 solar mass black holes - 3.0% of dark matter, and 1000 solar mass black holes - 11% of dark matter.
The scientists point to another important conclusion from the obtained results: black holes cannot be sources of gravitational waves. They suggest that it is more likely that the black holes detected by LIGO and Virgo were created as a result of the evolution of massive stars with low content of heavy elements, or the merger of smaller objects.
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Source: IAR, PAP
