Black hole Porphyrion emits energy across 23 million light years – 09/29/2024 – Science

Who knew a dragon’s tongue could be so long?

Astronomers announced last week that they had discovered a black hole emitting energy 23 million light years into intergalactic space. Two jets, shooting in opposite directions, make up the largest beam ever seen in the sky — about 140 times longer than the width of our own Milky Way galaxy, and more than 10 times the distance from Earth to Andromeda, the world’s largest spiral galaxy. next.

Follow-up observations with optical telescopes traced the flare to a galaxy 7.5 billion light-years away that existed when the Universe was less than half its current age of 14 billion years. At the heart of this galaxy was a black hole expelling energy equivalent to the production of more than 1 trillion stars.

“The Milky Way would be a small dot in these two gigantic eruptions,” said Martijn Oei, a postdoctoral researcher at the California Institute of Technology. Oei led the team that made the discovery, which was reported in Nature on September 18 and announced on the magazine’s cover with an illustration reminiscent of a “Star Wars” poster. Astronomers named the black hole Porphyrion, after a giant in Greek mythology — a son of Gaia — who fought the gods and lost.

The discovery raises new questions about how such black holes could affect the evolution and structure of the Universe.

“Astronomers believe that galaxies and their central black holes co-evolve, and a key aspect of this is that the jets can spread enormous amounts of energy that affect the growth of their host galaxies and other nearby galaxies,” said S. George Djorgovski, an astronomer at the Caltech who was part of the research team. “This discovery shows that its effects can extend much further than we thought.”

Astronomers are used to seeing jets shooting from the centers of galaxies. But most jets don’t extend beyond their host galaxy, Oei said.

“Porphyrion shows that small and large things in the Universe are intimately connected,” added Oei. If the jet were shrunk to the size of Earth, the black hole would be just two-tenths of a millimeter in diameter. “These giant jets are really incredible,” he said. “It’s as if a single amoeba was capable of generating two powerful Earth-sized streams of energy.”

Paradoxically, black holes — cosmic wells from which not even light can escape — may be the brightest objects in the Universe. As anyone with a plunger knows, trying to force too much stuff too quickly down a drain can cause it to overflow, causing a mess all around.

With a black hole, gas and other materials gain energy as they are drawn into a hot disk spinning near its edge. The internal pressure of this accretion disk can squeeze some of the energy out through space.

That’s what’s happening at the center of M87, a giant elliptical galaxy about 50 million light-years from Earth that has a spike of light shooting from its core. The galaxy is home to a black hole 6 billion times more massive than the Sun. (In 2019, the Event Horizon Telescope captured the first image of it.) But its jet extends only about 100,000 light-years before it collapses. dissolve into patches of radio noise.

For the past few years, Oei and his team have been mapping the sky using a European network of radio antennas known as LOFAR, which stands for Low-Frequency Array. The team assembled an army of citizen scientists to help examine the images. They weren’t looking for giant black hole jets, but they found them anyway. “We had no idea there were so many,” Oei said.

In 2022, the team announced that they had found a plasma plume 16 million light-years long, roughly the width of 100 Milky Ways. They named her Alcyonius, another ancient Greek giant who fought (unsuccessfully) against the gods for supremacy over the cosmos. He was the record holder until Porfirion.

The largest jet was first spotted by Aivin Gast, an Oxford student who joined Oei’s project after his studies in archeology and ancient history were interrupted by the coronavirus pandemic.

“Aivin would create a list of jet features in the radio sky, which I would then check and confirm or rule out, with additional radio and optical data,” Oei said in an email. “After finding Porphyrion, we were both very excited, but initially it was ambiguous which galaxy the jets actually emerged from.”

He added, “After the giant nature of the jets was finally confirmed, Aivin took advantage of his classical knowledge and proposed giving the system the beautiful name Porfirion, which it now bears.”

The intriguing question is what Porphyrion is doing to the rest of the Universe. Cosmologists have discovered that the visible features of the Universe are structured in a web-like manner, with galaxies grouped into gigantic clusters and connected by thin filaments that stretch across dark voids tens or even hundreds of millions of light-years long. In Porphyrion’s time, this cosmic web was half the size it is now; such jets would have been large enough to affect the overall web, reaching deep into the voids and depositing energy and heat there.

The energy from such jets, astronomers say, could have heated interstellar gas and prevented it from cooling and condensing into stars. Another possibility is that the jets are responsible for spreading magnetic fields in the voids. “Magnetism on our planet allows life to thrive, so we want to understand how it came to be,” said Oei.

The search for more giant jets continues. So far, after searching about 15% of the sky, Oei’s project has found 8,000 jets more than 3 million light-years long. When finished, he said, his team could find up to 1 million giant jets between Earth and Porphyrion.

“I think it’s pretty clear that what we’re seeing is really just the tip of the iceberg,” he said.