Globular clusters are one of the most interesting and at the same time beautiful objects in the night sky. Balls are made up of tens or even hundreds of thousands of stars, and they were usually formed before the Milky Way was formed and contain many unknowns.
Recently astronomers noticed that one looks different from the others. Palomar 5 hides more secrets than her friends.
Over the past few years, astronomers observing our near galactic surroundings have identified more than 30 different, longer, shorter, rarer and denser streams of stars orbiting our galaxy in what’s called a galactic halo. These streams are mostly the remnants of globular clusters or dwarf galaxies that have been disrupted by gravity, for example by another dwarf galaxy passing through. Tidal reactions in this case rip the stars from the outer layers of the cluster first, and if the passing object is massive enough, they rip the entire cluster, turning the spherical cluster of stars into a long stream. Studying the evolution of these currents is very difficult because most of them are no longer associated with any existing group.
Fortunately, there is Palomar 5
Palomar 5 is a very bulging star cluster that has its own stream of stars drifting away from it. An international team of scientists just discovered it ذلك Surprisingly, there are so many black holes inside this pool. It is estimated that there are about a hundred of them there. In the average mass there are at least three times less than them.
Effect? Black holes make up up to 20 percent. whole block block. The mass of each hole is approximately twenty times the mass of the Sun. All of them formed in supernova explosions of very massive stars. Given the short lifespan of massive stars, it can be assumed that black holes formed at the beginning of the assembly, billions of years ago.
Scientists from the University of Barcelona decided to analyze the process of formation of such an inflated cluster as Palomar 5. Massive objects in the center of mass are strongly bound by gravity, while stars lighter than them, especially those located farther away. From the center, gravity traps can easily escape and escape to outer space. The massive dynamics of black hole interactions mean that many stars are ejected from the center of mass to its fringes, or even completely outside, where they form stellar streams over time. As a result, over time, there were fewer and fewer stars in the cluster, and black holes were still in place, and therefore their number was surprisingly high for such a cluster.
Based on the Palomar 5 study, the researchers concluded that many of the recently discovered jets may have originated from star clusters dominated by black holes, and not necessarily from gravitational interactions with larger passing objects. This is important information for all astronomers who study the evolution of stars, black holes and globular clusters.