Giant black hole plasma jets discovered (artist's impression)
Artist's illustration of the longest jet system ever observed emanating from a black hole. A plasma jet shoots out above and below a supermassive black hole. The black hole is located at the heart of a massive galaxy 7.5 billion light years away from Earth. The jets eject cosmic rays, heat, heavy atoms and magnetic fields and affect the surrounding cosmic web – a vast network of thin filaments that connect and power galaxies in the Universe.
Image: 1/3, Credit:
E. Wernquist / D. Nelson (IllustrisTNG Collaboration) / M. Oei
Image from the LOFAR radio telescope
This image, taken by the European LOFAR (LOw Frequency ARray) radio telescope, shows the longest known jet pair from a black hole. Co-discoverer Aivin Gast from the University of Oxford named the two plasma jets after the giant Porphyrion from Greek mythology. They extend over 23 million light years, which corresponds to the size of 140 Milky Way galaxies in a row. The galaxy that harbours the supermassive black hole can be seen as a dot in the centre of the image. The largest blob-like structure near the centre is another smaller jet system.
Image: 2/3, Credit:
LOFAR Collaboration / Martijn Oei (Caltech)
Illustration of how jet systems penetrate galaxies
This artist's impression shows how a fictitious arrangement of huge jets can penetrate the cosmic web. Jets emerge from a galaxy, pass through the web-like structure and end up in areas of cosmic void. The discovery of the giant plasma jets dubbed 'Porphyrion' indicates that jets in the early Universe may have had a stronger influence on the formation of galaxies than previously assumed.
Image: 3/3, Credit:
Martijn Oei (Caltech) / Dylan Nelson (IllustrisTNG Collaboration). Some details were created with the help of AI.
An international research team has discovered the largest black hole plasma jets ever observed. These 'jets' have a total length of 23 million light-years and therefore extend much further into the Universe than previously thought.
Jets of this size could influence the formation of galaxies, and this pair of plasma jets discovered may have influenced the structure of the early Universe.
The results of the study were published in the 'Nature' scientific journal.
Focus: Spaceflight
Astrophysicists have discovered the largest black hole plasma jets ever observed in space. Black holes are known for swallowing matter in their immediate vicinity. However, they can also spew out large amounts of energy in the form of radiation or plasma jets. An international research team has now discovered a pair of jets with a combined length of 23 million light-years – corresponding to 140 Milky Way galaxies lined up side-by-side. The plasma jets shoot out above and below a supermassive black hole with the energy equivalent to several trillion Suns. Gabriela Calistro Rivera from the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) was involved in the research as part of her work at the European Southern Observatory (ESO). The study was published in the journal Nature on 18 September 2024, under the leadership of the California Institute of Technology (Caltech).
The jets, dubbed 'Porphyrion' after a giant from Greek mythology, originate from a black hole at the heart of a distant galaxy. It was already known that jets could extend beyond the boundaries of their galaxy. However, researchers were surprised to find that Porphyrion extends into the empty spaces of the Universe. To put this into context, stars are grouped into galaxies, which in turn are grouped into galaxy groups and galaxy clusters, with large empty spaces, or voids, in between. The galaxies are connected as if by a cosmic spider's web.
Influence on the formation of galaxies
"High-energy radiation and jets from black holes can drastically influence the growth and evolution of their galaxies. Porphyrion shows that these effects can take on unimagined proportions and influence the structure of our Universe," says Calistro Rivera.
This latest discovery suggests that the giant jets in the early Universe may have had a greater impact on the formation of galaxies than previously thought. The two jets are 7.5 billion light years away from Earth and thus date back to when the Universe was half its current age. Porphyrion therefore already existed during an early period in the Universe's history, when it was less expansive and the thin strands of the cosmic web were closer together. The megastreams thus extended over and influenced correspondingly larger parts of the Universe.
The jet pair was discovered with the help of the LOFAR (LOw Frequency ARray) radio telescope in Europe. The team also used the Giant Metrewave Radio Telescope (GMRT) in India, along with additional data from the Dark Energy Spectroscopic Instrument (DESI) project, as well as the W. M. Keck Observatory in Hawai'i. These all helped the research team to determine the correct host galaxy of the supermassive black hole generating the jets. In addition, DLR researcher Calistro Rivera combined this observational data to create a model able to determine the physical properties of galaxies and black holes. Thanks to this physical model, she also learnt how old, bright and massive the galaxy is, or in other words, how many stars it contains. In the case of the black hole, it turned out to be supermassive and very active.
New findings on black holes
When supermassive black holes become active, their immense gravity pulls in and heats up the surrounding matter. This releases large amounts of energy, either in the form of jets (known as jet-mode) or radiation in the visible or ultraviolet range (radiative-mode). Black holes in radiative-mode were more common in the early or distant Universe, while black holes with jets are more common in today's Universe.
"By comparing observational data from different parts of the electromagnetic spectrum with theoretical models, we were able to learn more about the physics of the black hole and its galaxy. This enabled us to discover that the huge jets in Porphyrion originate from an active black hole in radiative-mode," explains Calistro Rivera. The fact that Porphyrion originates from a black hole in radiative-mode is surprising – it was previously unknown that this mode could produce such large and powerful jets.
Since Porphyrion is located in the distant Universe where black holes in radiative-mode are abundant, the discovery also suggests that there could be many more gigantic jets. "We may only be looking at the tip of the iceberg," Oei says. "Our LOFAR survey only covered 15 percent of the sky. And most of these giant jets are likely difficult to spot, so we believe there are many more of these behemoths out there."
The next step for the team is to better understand how these megastructures affect their surroundings as they spread cosmic radiation, heat, heavy atoms and magnetic fields in the space between galaxies.
About the research
The Nature study 'Black hole jets on the scale of the cosmic web' was funded by the Dutch Research Council, the European Research Council, the UK Science and Technology Facilities Council, the UK Research and Innovation Future Leaders Fellowship and the European Union. The lead author is Martijn Oei from Leiden University and the California Institute of Technology (Caltech). Other authors include Martin Hardcastle from the University of Hertfordshire; Roland Timmerman from Durham University, Aivin R.D.J.G.I.B. Gast from Oxford University; Andrea Botteon and Francesco de Gasperin from the Institute of Radio Astronomy at the National Institute of Astrophysics in Italy; Antonio Rodriguez and S. G. Djorgovski from Caltech; Daniel Stern from the Jet Propulsion Laboratory, which is managed by Caltech for NASA; Gabriela Calistro Rivera from DLR and Reinout J. van Weeren, Huub J.A. Röttgering and Huib T. Intema from Leiden University.
