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Most powerful gamma ray burst ever seen came from colliding galaxies

Most powerful gamma ray burst ...
An artist's impression of GRB190114C, the most energetic gamma ray burst ever detected with the energy of 1 TeV
An artist's impression of GRB190114C, the most energetic gamma ray burst ever detected with the energy of 1 TeV
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An artist's impression of GRB190114C, the most energetic gamma ray burst ever detected with the energy of 1 TeV
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An artist's impression of GRB190114C, the most energetic gamma ray burst ever detected with the energy of 1 TeV
An artist's rendition of the most powerful gamma ray burst ever detected
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An artist's rendition of the most powerful gamma ray burst ever detected

Gamma-ray bursts (GRBs) are already the most energetic events we know of in the universe, and now, astronomers have detected the most powerful gamma ray burst ever. The competition isn’t even close, either – this event is almost a thousand times more powerful than your average GRB.

Such an intensely powerful signal can only come from some of the most energetic events in the cosmos. GRBs are produced when stars go supernova and collapse into either neutron stars or black holes, ejecting massive amounts of plasma at close to the speed of light and throwing out more energy in seconds than the Sun will in its lifetime.

The energy of these bursts is measured in electron volts (eV), where one electron volt is the amount of energy gained by a single electron when accelerated by one volt. For most GRBs, the afterglow is measured in a few dozen giga-electronvolts (GeV), which are billions of electron volts. But this latest detection far outshines that – it registered up to 1 tera-electronvolt (TeV), or a trillion electron volts.

“High-energy GRBs with energies in the region of tera-electron-volts were theoretically predicted,” says Masahiro Teshima, an author of the study. “Astronomers have searched for such powerful bursts for 15 years. My international team and I are proud to announce the discovery of the first gamma-ray burst with observed energies up to 1 tera-electronvolt, by far the highest-energy photons ever detected from a GRB.”

The event in question is named GRB190114C, and it was observed on January 14 this year. It was first spotted by two satellites designed to detect gamma-ray bursts – the Swift Observatory and the Fermi Gamma-ray Space Telescope – and to them, it looked like any other GRB. That’s because the short-lived initial burst is usually weaker, on the order of a few mega-electronvolts (MeV).

An artist's rendition of the most powerful gamma ray burst ever detected
An artist's rendition of the most powerful gamma ray burst ever detected

But it’s the afterglow, which shines brighter, that’s of particular interest. To watch for that, whenever these instruments detect GRBs they immediately signal to other facilities which can follow up observations. More than 20 other telescopes and observatories around the world focused their attention onto the spot to watch the celestial fireworks.

The afterglow began about a minute after the initial burst, and lasted about 20 minutes total. For the first 30 seconds or so, the glow was over 100 times stronger than the Crab Nebula, which is the brightest known gamma ray source in the galaxy. Its energy peaked at 1 TeV, but it lingered for a while down to 0.3 TeV, which is still very strong.

One of the observatories that peered at GRB190114C was Hubble. Although it can’t detect gamma rays, the space telescope was able to help determine how far away the event was, and what kind of conditions may have contributed to its extreme energy. It turns out that the burst came from a galaxy that’s currently colliding with another.

“Hubble’s observations suggest that this particular burst was sitting in a very dense environment, right in the middle of a bright galaxy 5 billion light years away,” says Andrew Levan, a lead author of the study. “This is really unusual, and suggests that this concentrated location might be why it produced this exceptionally powerful light.”

The research was published in the journal Nature.

Sources: University of Tokyo, Max Planck, Hubble

4 comments
Chris
The downside of a totally mechanistic mathemagical Cosmology is that the vocabulary is limited to 'collisions' and 'explosions'. This is the result of a narrow minded dependence on GRAVITY as the only driver in the wider universe. The Academic system has encouraged narrow thinking, a very left brain occupation, particularly by relying on mathematics as the confirmatory mechanism. Gone are the days when science tried experiments to backup their theories. A virtual, computer simulated univers has been created that may not bear any resemblance to reality. Surely Science requires alternative theories and constant testing with real data and preferably real experiments. This is no longer happening. "Criticism and dissent are the indispensable antidote to major delusions." Prof Alan Barth, University of California, Berkeley. A one-horse system is doomed to eventually fail as so many patches have been applied to prop it up. That is why I favour the Electric Universe option as it goes back to basic testable principles, allows the big picture right brain to contribute and does NOT require a menagerie of imaginery entities, such as 'dark matter', 'black holes' and 'neutron stars'. Quote: GRBs are produced when stars go supernova and collapse into either neutron stars or black holes, ejecting massive amounts of plasma at close to the speed of light and throwing out more energy in seconds than the Sun will in its lifetime. So much easier to have a high current overload in an electric star. The excess energy is dissipated by a plasma wideband emission - ooh it looks like gamma rays! Fancy that we can do it in a lab, so difficult. No maths involved!
piperTom
I had a hard time deciding what this "1 TEV" energy level referred to. A typical energy for at GRB is 10**44 joules and a joule is about 6*10**18 ev. I have to guess that the "1 TEV" is for a single gamma photon as received on Earth. Since this GRB is reported as most powerful, it'd by cool to know what the total energy was.
robert80
OK, I don't understand. You refer to TeV, which is indeed energy. But energy makes absolutely no sense in this context without further qualification. Do you mean "energy per photon"? Do you really mean "power" as in "TeV per second at the detector"? Because I promise, the actual event generating the burst had a lot more than 1 TeV of energy (almost an order of magnitude less than the collision energy of single collisions at the LHC), which is not impressive on the cosmic scale as the total energy of ANY event. If you mean "energy per photon", please say so. If you meant to say "intensity" (the only other measure of power that makes any sense it all), please say THAT, and indicate roughly what that means in terms of the total energy actually radiated in the GRB. As it is, I have no idea what to make of the story, because a TeV is order of 100 nanojoules, not impressive as macroscopic energies go for "events", but perhaps impressive in terms of single photon energies, if only because the photons produced would almost instantly decay in interaction with ordinary charged matter into a cascade of pair production (plenty of energy to produce e.g. electron-positron pairs) -- quite possibly all the way up to the serious massive particle scales seen at the LHC.
paul314
It sounds as if two things were going on simultaneously: lots and lots of gamma rays (total brightness/intensity) and gamma rays of much higher energies than expected (which would be 'color' if it were in the visible). So a much bluer burst, so to speak. And those gamma ray photons have to have not interacted much with anything since they were emitted.