A team of researchers recently observed a gamma-ray burst from a distant supermassive black hole that was tens of millions of times larger than the black hole’s event horizon, the region beyond which even light cannot escape.
The gamma-ray burst emitted photons billions of times more energetic than visible light, making it the most intense flare in the last ten years. It lasted for about three days and, according to the team’s analysis, was emitted from an area less than three light days across, or just under 15 billion miles (24 billion kilometers). The study, published today in the journal Astronomy & Astrophysics, describes the extreme environment surrounding the M87 black hole (conveniently and confusingly also called M87).
More than 300 scientists co-authored the paper, which explores the physics of a black hole. This cosmic phenomenon attracts matter to its mouth and energizes surrounding particles, turning them into massive jets of matter. These jets crash into objects in the surrounding space environment and can be gigantic; the pair of jets described in September are 140 times the width of the Milky Way galaxy.
“We still don’t fully understand how particles accelerate near a black hole or inside a jet,” said Weidong Jin, a researcher at the University of California, Los Angeles and author of the paper, in a university release. “These particles are so energetic that they travel at close to the speed of light, and we want to understand where and how they get that energy. Our study presents the most comprehensive spectral data ever collected for this galaxy, along with simulations that shed light on these processes.”
The team found variations between the position and angle of the event horizon and the position of the black hole jet, indicating that the interaction between particles and the event horizon affects the position of the jet.
“These efforts promise to shed light on the connection between the disk and the jet and reveal the origin and mechanisms of gamma-ray emission,” said Giacomo Principe, a researcher at the University of Trieste and co-author of the paper, in a release from the Center for Astrophysics at Harvard and the Smithsonian Institutes.
So far, only two black holes have been directly imaged. Because light cannot leave their event horizons, when we say “directly imaged,” we mean that the shadow of the black hole has been directly imaged at the center of an energetic, light-emitting accretion disk. The supermassive black hole at the center of the galaxy M87 was spectacularly discovered in 2019 and was the first to be imaged by humanity.
Subsequent observations have shown that the black hole wobbles and has a fluffier ring than previously thought. The team of the Event Horizon Telescope took an image of M87, and in 2022, based on it, took an image of Sagittarius A*, a black hole at the center of our galaxy.
“The observations – both the recent ones with the more sensitive EHT grating and those planned for the coming years – will provide invaluable information and an extraordinary opportunity to study the physics of the supermassive black hole M87,” added Principe.
As imaging techniques improve, as well as the models that astrophysicists use to understand these distant and extreme environments, we will get a better look at some of the structures that shape our universe. Studying these details of the universe may, in turn, lead to new discoveries about the limits of classical physics as we know it.
