A thick clump of stars a few light-years away has been a wonder in his heart. Instead of one relatively thick black hole, astronauts have discovered that the NGC 6397 global browser is wrapped around a collection of smaller, massive stones.
This may not only help us to better understand the formation of larger black holes, it shows that spherical assemblages may be of interest to wave astronomy as the black holes definitely pulling closer together towards hitting.
Global clusters of stars are often regarded as “fossils” of the first Universe. They are dense, spherical assemblages of about 100,000 to 1 million very old stars, some – like NGC 6397 – almost as old as the Universe itself. In any universe, all its stars were created at once, from the same cloud of gas. There are about 150 global collections on the Milky Way.
These objects are excellent tools for studying, for example, the history of the Earth, or the dark subject matter of the galleries they orbit around. Recently, however, astronomers have been taking a closer look at them as potential homes in a class of unattainable objects – intermediate black holes.
As the name suggests, these mid-levels sit between large stellar masses and supermassive black holes, the latter of which are usually found in galaxies centers.
Although the boundaries between intermediate black holes and supermassive black holes are not well defined at present, intermediate black holes are thought to be larger than a normally collapsed star (up to one hundred masses of sunlight). but not very high (between a million and a billion times more mass than a typical stellar black hole).
There is strong evidence for the presence of medium-sized black holes, however, rare and largely inconclusive. Theory and modeling suggest that they would be found in spherical assemblages, the gravitational heart around which the stars gather, like larger galaxies around proud black holes.
The buildings at NGC 6397, about 7,800 light-years away, suggested that one of these intermediates may be at its center.
Since we can’t see black holes (because they don’t emit visible radiation), astronomers took a closer look at the orbits of the stars in the cluster, based on years of Hubble data, to see if they were marking between -medical- large black hole.
“We found very strong evidence for an invisible mass in the dense heart of the globular universe,” said astronomer Eduardo Vitral of the Paris Institute of Astrophysics in France, “but we were surprised to find that the mass is not extra. This is like a point ‘(that would be expected for a large, isolated black hole) but expanded to a few percent of browser size. “
This is consistent with a type of drag called dynamic counter-movement, in which objects in the movement of the cluster alternate, sending objects denser, more towards the heart, and objects that do not. not so much towards the edge.
Dead stars such as white dwarfs, neutron stars and black holes are denser than primitive stars, so they move in, emitting the lightest stars.
“We used stellar evolutionary theory to conclude that most of the extra mass we found was in the shape of a black hole,” said astronomer Gary Mamon of the Paris Institute of Astrophysics.
It is also consistent with two recent papers, which found that, instead of intermediate black holes, numbers of stellar mass black holes may reside in central regions of spherical assemblages. Now these conclusions have been confirmed.
“We are the first study to give both mass and size of what appears to be a collection of mostly black holes in the middle of a collapsed global browser,” Vitral said.
This is useful information both in the study for stellar-mass black holes and the hunting of intermediate black holes. Now that we have speculative evidence that this can happen, astronomers can update their searches to eliminate similarly-occurring earth records.
Other black hole research has implications as well.
As the items continue to sink towards the center of the cluster, the team believes that, eventually, they will start spinning into each other and coming together. Eventually – a long time from now – this could lead to a medium – sized black hole.
Immediately, this ongoing process suggests that the cores of these assemblages could be very important for gravitational wave astronomy. Because they are so tightly packed, the processes should be speeded up, which means we could look at these areas both to study pre-union situations, and to try to get over the pull wave events that occur when the black holes come together.
The research was published in Astronomy & Astronomy.