‘Black Hole Police’ Arrest Rare Object in Neighboring Galaxy

Of all the leading scientists working at the forefront of global astrophysics, few are as qualified to talk about black holes as the physicists at the European South Observatory (ESO).

This institution is one of the absolute references for everything related to these cosmic monsters. We already owe them a mountain of revolutionary work on this theme, starting with the very first image ever taken of a black hole, just that! More recently, they once again distinguished themselves by presenting the first image of Sagittarius A*, the supermassive black hole that structures the entire Milky Way (see our article).

When the “Black Hole Police” investigate

These exploits speak volumes about ESO’s reputation: when its teams talk about these objects, the entire scientific community shuts up and listens. Even when a research paper that claims to have discovered a particular black hole makes it through peer review, it’s not uncommon for ESO to come ” debunk » these articles thereafter (see our article).

This reference status has often led the ESO to position itself as an arbiter; a situation that earned him the nickname of ” black hole police “. When this astrophysical militia unanimously validates a rare observation, it is therefore a small event in itself, and it is precisely what happened yesterday.

In a communicatedthe institution announced the discovery of VFTS 243, a dormant black hole which resides in the Large Magellanic Cloud — a satellite galaxy of the Milky Way. It’s here very first time that the presence of an object of this type has been unambiguously confirmed outside our galaxywhile the researchers’ models suggest they should be extremely common.

A hunt for fugitive black holes

Black holes in this category appear at the end of a star’s life cycle, when the latter begins to collapse under the effect of its own gravity. This stage typically marks the onset of intense X-ray emission; it is this radiation that usually allows astronomers to locate these objects.

But dormant black holes like this one are, on the contrary, particularly inconspicuous; they emit much lower radiation levels. It makes their almost impossible to detectsince they absorb all other electromagnetic waves such as visible light or infrared.

” It’s amazing that we know almost no dormant black holes, knowing that astronomers consider them to be extremely common “, explains Pablo Marchant, co-author of the study. And this is not an exploration. To get their hands on this invisible curiosity, researchers had to make great efforts.

Since it is impossible to locate them by direct methods, specialists look for dormant black holes using indirect techniques. Most often, they are interested in specific massive stars; they can sometimes form a couple with these objects before merging. In this case, ESO troops scanned more than a thousand stars in the Tarantula Nebula before coming across the coveted object.

And even after this extremely painstaking work, the ESO researchers lived up to their reputation by applying their usual skepticism to their own results. ” As a researcher who has debunked several potential black holes in recent years, I was extremely skeptical of this discovery. explains Tomer Shenar, lead author of the study. And he wasn’t the only one.

” When Tomer asked me to recheck, I had my doubts “, continues Kareem El-Badr, one of the co-authors of the study. But even after flipping the data all over the place, the latter didn’t ” not found any plausible explanation that does not involve a black hole “.

‘Enormous implications’ for black hole physics

Now sure of their facts, the authors of the study were able to move on to the interpretation phase. The objective: to understand why and how these cosmic gluttons can remain so discreet. And the researchers have their own idea about the answer; this apparent calm would be directly linked to the circumstances of the birth of the black hole.

” The star that formed black hole VFTS 243 appears to have collapsed entirely, with no signs of an explosion “. A very surprising element, since the end of life of stars in this category is generally marked by a gigantic supernova which then gives way to a normal black hole.

It could therefore be an aborted supernova, as in the case of the “zombie” star recently discovered by other astronomers. For now, the dynamics of this phenomenon remain very mysterious. But in any case, this discovery will have huge implications for the origin of black hole mergers “says Shenar.

It is therefore a well-conducted investigation for the shock inspectors of the “ black hole police “. And his troops are already hoping that other researchers will come and challenge their interpretation to open up new avenues of research.

” Of course, I expect other researchers to dutifully review our analysis and try to cook us alternative models. “, anticipates Shenar in conclusion. ” It’s very exciting to be part of this project “.