M87* is the supermodel of black holes. If not too long ago it was unthinkable to photograph a black holeToday it is still complicated, but it is already a reality. A reality that, in fact, has been possible thanks to M87*, the black hole from which most of the photographs published to date come. First it was his shadow that was captured making history and now it has been the jets of matter that it expels
There is still much unknown about the jets that expel black holes. Therefore, being able to study them in a photograph like the one just published in Nature It’s a breakthrough.
It has been achieved thanks to a network of radio telescopes located throughout the world, which act as a great telescope of the earth size. Thanks to that and to Artificial Intelligence, recently it was also possible to improve the resolution of that first photograph of the shadow of the black hole M87*. Hopefully, many more will be available in the future, thus improving our understanding of these gluttonous universes.
Why is M87* the perfect black hole to photograph?
Almost all galaxies have a large black hole at their center, but not all are equally good candidates to photograph.
In the case of M87* it was chosen for two reasons. On the one hand, because it’s pretty close from Earth, about 55 million light years. And, on the other, because it is very bigwith 6.5 million times the mass of the Sun.
The other black hole that has been photographed is Sagittarius A*. It is much closer to Earth, since it is precisely the black hole that is located in the center of our galaxy. However, it is Much smaller, with a mass a thousand times less than that of M87*. For this reason, when it was decided to go for the jets of a black hole, it was decided to resort again to M87*.
A large network of telescopes to immortalize the jets
Black holes are so massive that not even light can escape their gravitational pull. For this reason, it is known that around them form matter discs that spin before being swallowed by them. It’s something like water spinning before it’s drawn into a sink drain.
They all have something known as event horizon, which is the distance at which nothing can escape from the black hole. This is something that was known and studied long before the first image of a black hole was obtained. However, the photographs help to understand the process much better.
On the other hand, there are the jets. It is also known that any object that is trapped by a black hole, before passing behind the event horizon and being completely engulfed, is so strongly pressured by the tidal forces generated by gravity that a small part of the matter shoots out at the speed of light. Very roughlyIt is something like when we squeeze a bottle of ketchup or a lemon, and part of its content shoots out instead of going to the plate in which it is to be deposited.
These jets have been known for years, but there are still some data that remain unknown. But now, thanks to this new photograph, they can be studied in more depth. It has been captured thanks to images taken by the Global Millimeter VLBI Array, the Atacama Large Millimeter/submillimeter Array, and the Greenland Telescope.
Previously, to obtain the first photo of the black hole, radio waves of 1.3mmwhile this time they have been used 3.5mm. Thus, both the shadow and the jets can be seen. It has been possible because the antennas of the telescopes are so far apart that the whole planet acts as one big antenna. Without a doubt, it is a great finding that shows that taking pictures of black holes has only just begun.
