Scientists have witnessed never-before-observed changes in the galaxy
The awakening of a supermassive black hole in the constellation Virgo was first recorded, almost “live”, by an international group of scientists from the European Southern Very Large Telescope observatory (VLT ESO). The light from a black hole that is millions of times the mass of our Sun illuminated almost the entire galaxy SDSS1335+0728 and became accessible to our telescopes. Vladimir SURDIN, candidate of physical and mathematical sciences, senior researcher at the P. K. Sternberg State Astronomical Institute, associate professor at the Faculty of Physics at Moscow State University, spoke about the reasons for such unprecedented activity, as well as about what would happen if something similar happened in our Milky Way galaxy. .
This is how an artist saw a galaxy “ignited” by a black hole. Photo: eso.org.
Galaxy SDSS1335+0728, located 300 million light-years from Earth, shone brighter than ever (in X-rays) at the end of 2019. To understand what happened to it, astronomers around the world immediately turned their space and ground-based telescopes to it, including ESO's VLT. In a paper published on June 18, 2024, scientists concluded that they had witnessed never before observed changes in the galaxy. The most likely assumption is that it shone as a result of the sudden awakening of a massive black hole in its core.
“Imagine that you have been observing a distant galaxy for many years, it has always seemed calm and inactive…” comments the discovery Paula Sánchez Sáez is an astronomer at ESO in Germany and lead author of the paper. “Suddenly, its core begins to show dramatic changes in brightness, unlike any typical events we have seen before.”
The authors do not hide their surprise at how long this nucleus remains active. The fact is that in all known cases, black holes begin to glow brighter either at the moment of their formation from supernova explosions, or due to “eating” nearby objects (when tidal forces lead to their rupture). But in all cases, the change in brightness lasts only a few tens or, at most, a few hundred days.
In this case, SDSS1335+0728 continues to brighten today, more than four years after it was first seen “turning on.”
Not only that, astronomers have recorded much more light in the ultraviolet, optical and infrared ranges compared to 2019 data!
“This behavior is unprecedented,” says Sanchez Saez.
“We know that black holes become active from time to time, most often due to “devouring” stars that fall into their sphere of attraction,” says Vladimir Surdin. – The uniqueness of this case lies only in the fact that we saw the light of a heating substance falling into the hole almost in real time.
– It is not yet possible to answer this question precisely, we need to observe this galaxy within ten years — then it will become clear. In general, the larger the black hole, the slower everything happens around it — this has been proven. If she has captured something, then this “something” will fly around her for a very long time, possibly increasing the glow as it is destroyed.
— Certainly. Moreover, the active nucleus shines with optical rays and illuminates not only its own, but also neighboring galaxies. This, for example, happens in the constellation Perseus, where one black hole shines so that thousands of other galaxies living around it “feel” its activity.
— Visually, we could see it as an ordinary star in the sky.
— We have our own center of the Galaxy in the form of a black hole called Sagittarius A*. This is a supermassive hole that is four million solar masses. She is not the largest in the Universe; one might say, she is of average fatness. It is slightly visible in X-rays, but not in optics.
If she had decided to “have a hearty lunch,” then even then we would not have seen this process with our eyes. The fact is that our Solar system is located in the disk of the Galaxy, and there are a lot of clouds of dust and gas in it, which quite well shield from us what is happening in the center. So, if it were to light up in the sky tomorrow, we could only “see” a kind of “lantern” in the X-ray or radio ranges.
— About a hundred thousand years ago, this black hole was very is active — we notice this only now.
— From it, fragments of hot, but gradually fading gas are still scattering in all directions.
– A few years ago, astrophysicists photographed a permanent accretion disk (glow at the boundary with the hole’s event horizon. —) with a delay of 26 thousand years (that’s how much light comes from it to us). We can say that by cosmic standards this is her present of our Sagittarius A*.