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Researchers have taken an important step in solving the mystery of the movement of stars in the largest star cluster in our galaxy — Omega Centauri. For a long time, scientists could not determine what causes the abnormally high speeds of the stars in the center of the cluster: the presence of an intermediate-mass black hole (IMBH) or a cluster of ordinary stellar-mass black holes.
A new study conducted by scientists from the University of Surrey in collaboration with the Spanish Instituto de Astrofísica de Canarias and the French LAPTh proves that at the center of the cluster is likely a group of stellar-mass black holes rather than a single large black hole. The conclusions are based on a combination of data on the velocities of the stars with measurements of the acceleration of pulsars, ultra-precise cosmic clocks that allow us to probe the gravitational field.
Thanks to these measurements, the researchers determined that if the IMBH does exist in the center of Omega Centauri, then its mass does not exceed 6 thousand solar masses. This is much less than previously expected.
What does this mean?
Intermediate-mass black holes are considered the key to understanding the formation of supermassive black holes in the centers of galaxies. They could be the "missing link" between small black holes of stellar mass and giants that weigh millions of solar masses. However, their existence remains unproven.
"This study helps close a long-standing debate and opens up new opportunities for the study of black holes in star clusters." Andres Bañares Hernandez, lead author of the study, noted. According to him, Omega Centauri is an ideal environment for studying both black holes and pulsars, which are found in large numbers here.
The results of the study were published in the journal Astronomy & Astrophysics.
Researchers have taken an important step in solving the mystery of the movement of stars in the largest star cluster in our galaxy — Omega Centauri. For a long time, scientists could not determine what causes the abnormally high speeds of the stars in the center of the cluster: the presence of an intermediate-mass black hole (IMBH) or a cluster of ordinary stellar-mass black holes.
A new study conducted by scientists from the University of Surrey in collaboration with the Spanish Instituto de Astrofísica de Canarias and the French LAPTh proves that at the center of the cluster is likely a group of stellar-mass black holes rather than a single large black hole. The conclusions are based on a combination of data on the velocities of the stars with measurements of the acceleration of pulsars, ultra-precise cosmic clocks that allow us to probe the gravitational field.
Thanks to these measurements, the researchers determined that if the IMBH does exist in the center of Omega Centauri, then its mass does not exceed 6 thousand solar masses. This is much less than previously expected.
What does this mean?
Intermediate-mass black holes are considered the key to understanding the formation of supermassive black holes in the centers of galaxies. They could be the "missing link" between small black holes of stellar mass and giants that weigh millions of solar masses. However, their existence remains unproven.
"This study helps close a long-standing debate and opens up new opportunities for the study of black holes in star clusters." Andres Bañares Hernandez, lead author of the study, noted. According to him, Omega Centauri is an ideal environment for studying both black holes and pulsars, which are found in large numbers here.
The results of the study were published in the journal Astronomy & Astrophysics.
