In 2018, it was revealed that a groundbreaking Earth-sized telescope had captured the first image of a black hole. The same instrument, the Event Horizon Telescope (EHT), has now witnessed the same black hole explode in a powerful, unexpected explosion. Scientists hope that by studying this emission, they can better model the structure around supermassive black holes.
In April and May 2018, this flare lasted for about three days, starting from supermassive black hole designated M87*this is in the core Galaxy M87about 55 million light-years away from us. 25 ground-based and orbiting telescopes EHT Think of the bursts as high-energy light called gamma rays.
Not only was this the first outburst from M87* since 2010, but the eruption was also more active than the black hole’s typical flares.
Supermassive black holes are thought to exist at the centers of all large galaxies, including our own, Milky Way.
M87* emerges from the supermassive black hole at the center of the Milky Way, Sagittarius A* (A*Sergeant). Our supermassive black hole has a mass of about 4.3 million suns, while M87* has a mass of about 5.4 suns billion sun!
But M87* is also different from Sgr A* because this more distant black hole is eat greedily. This feeding results in jets associated with high-energy flares, such as the gamma-ray burst discovered by the EHT in 2018.
“Combined with the EHT’s submillimeter observations, the new data collected in multiple radiation bands provides a unique opportunity to understand gamma ray emission “These observations can shed light on some of the main questions in astrophysics that remain unresolved,” project leader Giacomo Principe, a researcher at the University of Trieste, said in a statement.
“How do the powerful relativistic jets observed in some galaxies originate? Where are the particles responsible for emitting gamma rays accelerated? What phenomena accelerate them to energies of trillions of electron volts? cosmic rays?
Black holes are devourers of chaos
What really makes black holes special is the vast amount of matter surrounding them. While some like Sgr A* exist in relatively empty pantries (if our black hole were a human, it would feed on a grain of rice every million years), others like M87* There are abundant substances available for consumption.
However, despite our image of a black hole as an all-consuming, all-devouring cosmic titan from which nothing can escape, supermassive black holes like M87* are actually quite massive. wasteful eater. Like a grumpy toddler, most of the food prepared for these black holes ends up being violently thrown away.
The material surrounding a supermassive black hole exists in a flat cloud called an accretion disk and in the form of superheated gas called “plasma” because it still has Angular momentumor rotate. This angular momentum also means that this plasma cannot fall directly into the black hole; instead, it orbits the central supermassive black hole and is gradually fed into it.
However, supermassive black holes are also surrounded by powerful magnetic fields. These transport material from the accretion disk to the poles of the black hole. At some point, these particles are accelerated to nearly the speed of light and high energy jet.
These jets are accompanied by bursts electromagnetic radiation Just like the gamma ray flares witnessed by the EHT.
The energy bursts of M87* observed by the EHT show that near-light speed jets erupting from around the black hole extend to surprising distances.
The jet is tens of millions of times wider than the black hole itself. The size difference is so vast, it’s like a blue whale bursting out from a single bacterium.
How a black hole fires these jets remains a mystery, and EHT scientists hope these observations will help shed light on the mystery.
“In particular, these results provide the first opportunity to identify the point of particle acceleration that causes flares, which could resolve the long-standing debate about the origin of cosmic rays (extremely high-energy particles) detected in space on Earth,” Principe continued .
At the heart of EHT lies collaboration between instruments, and these results are a striking example of this.
In addition to what has been assembled to turn the EHT into an Earth-sized telescope, the campaign is also turning to space-based instruments, e.g. Fermi, Nu Xing, chandra, and fast.
“Fermi-LAT discovered a significant increase in flux during the same period as other observatories, helping to identify regions of gamma-ray emission during the increase in brightness,” said Elisabetta Cavazzuti, director of Fermi. “This laboratory has demonstrated once again that M87 The importance of coordinating observations at multiple wavelengths and sampling them adequately to fully characterize the spectral variability of the source, which may extend to different time scales, and to have the widest possible field of view, intact across the entire electromagnetic Spectrum.
Thanks to collaboration between these and other telescopes, scientists were able to distinguish distinct changes in the angle of the jets coming from M87’s core. This seems to happen every year.
The team also noted changes event horizonthe light-harvesting outer boundary of each black hole. This shows a connection between the event horizon and the powerful jets emitted by the black hole.
“exist first picture During the 2018 observation campaign, it was discovered that this ring is not uniform and therefore has asymmetries (i.e. brighter areas),” Principe concluded. “Follow-up observations in 2018 and the scientific research associated with this publication confirmed these data, but highlighted a change in the positional angle of the asymmetry.
The team’s findings were published in the journal on Friday (December 13) Astronomy and Astrophysics.