• 2 days ago
The jets dubbed Porphyrion stretch for 23 million light years, equal to 140 Milky Ways lined up side by side. They erupted from a black hole that existed when the universe was half its current age.

Credit: S. Landis/ K. Rappaport (SCL)
Transcript
00:00We've discovered a twin jet system emerging from a black hole, and this pair of jets is
00:17about 23 million light years long.
00:22That is not just the solar system, not just the Milky Way, but 140 Milky Way diameters
00:27in total.
00:29That makes it the largest structure made by an astrophysical body, like a black hole,
00:34ever observed.
00:35I'm Martijn Nui, I'm a radio astronomer here at Caltech, and I study cosmic web and giant
00:42jet systems from black holes.
00:47In the center of every galaxy there is a big black hole of about a million to a billion
00:53solar masses.
00:54These swallow stars and dust and plasma that comes close to it, but they do not swallow
00:59everything that comes close.
01:01A tiny fraction of the material is being ejected again, just before it falls into the black
01:06hole, and those particles are funneled into two jets.
01:12These jets accelerate particles to close to the speed of light, therefore the jets start
01:16to glow in synchrotron radiation, and that is radiation that you can see with radio telescopes
01:21on Earth.
01:24What we tried to look for initially was a radio signature of the cosmic web.
01:30The cosmic web is a large scale structure of the universe, it is the network of matter
01:34that pervades all space between the galaxies.
01:40It is possible to image the cosmic web using radio telescopes, we think, and while doing
01:44that we found some very big outflows that were coming from galaxies, and using our new
01:50images we were able to find 10,000 of these new objects.
01:56So it seems that every massive galaxy has black hole jets to some degree, but what we
02:01are discovering now is that an increasing number of galaxies actually have black hole
02:05jets that reach far out beyond the border of the galaxy itself.
02:12Whenever the jets reach the intergalactic space, then we think they have a big influence
02:17on heating the medium between the galaxies, and on magnetizing it.
02:22Those are two very big questions.
02:24How did the universe get magnetized, and how did the large scale structures that lie between
02:29galaxies come to be?
02:34One of the unexpected realizations of finding this giant jet system is that black hole jets
02:39can reach the scale of the cosmic web.
02:41They are so big that they can reach, in principle, everywhere.
02:45What we are now seeing is that they were also emerging far into the past.
02:49The very giant one that we have discovered lived even in the first half of the universe's
02:53existence, towards the detection limits of our current instruments.
02:59What I am now researching is whether those giant jets can actually magnetize, whether
03:03they have spread magnetism in the medium between the galaxies.
03:07So the magnetism that started in the cosmic web eventually went into galaxies, then went
03:13into the formation of stars, and the young sun, when it was forming, transferred magnetic
03:18fields out to their planets.
03:21So even for understanding the origin of life, it is important to know how magnetism in the
03:25cosmos has come to be.

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