José Manuel NievesSEGUIR Updated: Save Send news by mail electrónicoTu name *

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In the catalogues of astronomers, there are thousands of pictures of galaxies in full collision. It is a process that can take hundreds, sometimes thousands of millions of years to complete. We can not live so long to see a complete one, but yes that we can capture different collisions at different stages to find out how they work. It is as if an insect that lives only a day, I would like to study the phases of the life of a human being. Could not. But if you would capture separate images of many children, adolescents, young people, mature people and seniors, then it could be a pretty good idea of how it develops the life of a person.

that’s why we know quite well how to develop the mergers between galaxies , the forces that come into play and how, in the end, remain distributed in their hundreds of thousands of millions of stars. However, we do not know nothing, or almost nothing, what happens with the huge supermassive black holes in the centers of these galaxies. What is fused as well, to give place to a “monster” even bigger? Do, or or or may merge and continue every one to his own way?

Still more monstrous

The calculations of astronomers say that such massive and dark galactic nuclei, whose masses may be tens of thousands of millions of times greater than the Sun could, if certain conditions exist, merge to give rise to black holes even more massive , sending for the whole of space-time. gigantic gravitational waves.

But these same simulations also say that if the merger between galaxies there is any asymmetry, something quite usual, the black hole newly forged could be expelled violently of the galaxy, and condemned to wander alone through the Universe. Do you solo? Not at all, because in their flight would take them to a whole swarm of stars buzzing around, giving place to a strange object theorized to the end of the last decade of the nineties and so-called “Star System Hipercompacto” (HCSS for its acronym in English). It would look just like a supermassive black hole surrounded by a tight group of stars captured by its gravity, and moving around on their own in the vastness of space.

The existence of the HCSS would be, by itself, a solid proof of the phenomenon of ejection of supermassive black holes of their galaxies by means of what is known as “recoil from gravitational waves”. The only problem is that it still has not been found none.

Looking for among the most small

in order To facilitate the search, astronomers have followed another strategy. The idea is that if this phenomenon happens to the huge scale of a supermassive black hole, should also occur at smaller scales. For example, we know that the smaller black holes, of stellar mass, can be merged. In fact, the detectors of gravitational waves have been able to already see a good number of such mergers.

And then there are the so-called “black holes of intermediate-mass” . That is to say, neither so small as the stars and as large as the supermassive black holes. But its existence is not proven. However, when our galaxy, the Milky Way, was much younger than now, probably also its central black hole, Sagittarius A*, which today has four million solar masses, was much smaller.

And the collision with a dwarf galaxy (and with a central black hole is also small) could have given rise to one, or several, of these black holes of intermediate mass, between 100 and 10,000 times the mass of the Sun, and that also would have been ejected from the galactic center. The idea is that, just like their “older brothers”, also these black holes of intermediate mass would be accompanied by an entourage of stars . In other words, they would be as small HCSS.

the simulations of the scientists predict that there should exist several hundreds of these black holes in the halo of our galaxy. Unfortunately, neither has found none until now.

In fact, the evidence on the existence of black holes of intermediate mass is, by now, quite scarce. is Considered the “missing link” of black holes , some studies have become very close to their discovery, though at the moment there have been no conclusive results. Its very existence is subject to debate.

But what are we looking for?

So, a team of astronomers at the netherlands Institute for Space Research (SRON) and the University of Redboud, in the Netherlands, had the bright idea that some of the HCSS could have been already collected by previous studies and “be lost between the data” of the esa Gaia mission or the Sloan Digital Sky Survey. So you went to review old data set in search of signs of HCSS.

in doing so, however, they realized that nobody had made detailed predictions of how they should be are exactly those star clusters hyper-compact, so that, although they were in the data, there was a set of tools able to identify them.

In a new study, published in “Monthly Notices of the Royal Astronomical Society”, the researchers simulated how it had to be the HCSS, with detailed predictions of their colors, appearance and spectra. But not only that, but by showing how they would appear in the data groups of the HCSS in the middle of the rest of the data of the observation and, even, showing how they would look on those strange objects in an image of the telescope.

What is certain is that the team of researchers has failed to even identify a HCSS. As they explain, that will be, precisely, the next step in your research. But the publication of their simulations means that from now on also other astronomers will have the tools to search for these elusive objects in space.

Find the missing link

If someone gets it, they’ve found a Star System’s Hyper compact will be shown, also, that black holes of intermediate mass exist of truth. In the words of David Wood, first author of the article, “if in fact we find groups stellar hyper-compact, at the same time we will demonstrate the existence of black holes of intermediate mass”.

it Is an open question if the supermassive black holes, with masses ranging from millions to billions of times that of the Sun, are or are not capable of fusing . Some estimates suggest that if the two of them to come enough (a parsec of distance, which is equivalent to s up to 3.2 light years), its own orbital energy would keep orbitándose each other and in a stable manner even for thousands of millions of years.

What we do know is that the stellar-mass black holes (between 5 and 100 times the mass of the Sun) can fuse. And if you were able to find some HCSS in the halo of our galaxy, it will be a test of that also black holes of intermediate mass can do so, which would increase the probability that black holes larger could merge also.

These elusive and compact balls of stars that are the HCSS, then, are the key to solve in one stroke several mysteries in space. Now we just have to find them.