SoylentNews is people
SoylentNews
from the just-demolition-work-for-the-intergalactic-superhighway dept.
Astronomers detect biggest explosion in the history of the Universe - ICRAR
Scientists studying a distant galaxy cluster have discovered the biggest explosion seen in the Universe since the Big Bang.
[...] It released five times more energy than the previous record holder.
Professor Melanie Johnston-Hollitt, from the Curtin University node of the International Centre for Radio Astronomy Research, said the event was extraordinarily energetic.
"We've seen outbursts in the centres of galaxies before but this one is really, really massive," she said.
"And we don't know why it's so big.
"But it happened very slowly—like an explosion in slow motion that took place over hundreds of millions of years."
The explosion occurred in the Ophiuchus galaxy cluster, about 390 million light-years from Earth.
It was so powerful it punched a cavity in the cluster plasma—the super-hot gas surrounding the black hole.
Lead author of the study Dr Simona Giacintucci, from the Naval Research Laboratory in the United States, said the blast was similar to the 1980 eruption of Mount St. Helens, which ripped the top off the mountain.
"The difference is that you could fit 15 Milky Way galaxies in a row into the crater this eruption punched into the cluster's hot gas," she said.
[...] The discovery was made using four telescopes; NASA's Chandra X-ray Observatory, ESA's XMM-Newton, the Murchison Widefield Array (MWA) in Western Australia and the Giant Metrewave Radio Telescope (GMRT) in India.
Journal Reference:
Giacintucci, S., Markevitch, M., Johnston-Hollitt, M., et al. Discovery of a giant radio fossil in the Ophiuchus galaxy cluster, (DOI: 10.3847/1538-4357/ab6a9d)
With apologies to Marvin the Martian:
Earth-shattering kaboom? Nope, that's not it.
Sun-shattering kaboom? Think larger.
Galaxy-shattering kaboom? Still way too small.
Galaxy-Cluster-shattering Kaboom! Now you've got it!
Don't Panic!
(Score: 1) by khallow on Monday June 01 2020, @06:23PM
The mass-energy content [wikipedia.org] of a gram of matter is roughly 10^14 J (Joules). Tsar Bomba, the largest nuclear weapon ever detonated released roughly the energy content of 2 kg. The Sun's power output is roughly four million metric tons equivalent of energy per second. Typical energy release of a supernova is roughly 10^24 metric tons equivalent, which is also roughly the estimated lifetime output of the Sun - which in turn is about a thousandth of the mass of the Sun (in other words, over it's lifetime, the Sun effectively converts 0.1% of its mass into energy). The largest hypernovas release on the order of 0.1 solar masses as energy. None of what I have mentioned so far makes much of a dent in a galaxy like the Milky Way (which is comparable to the doughnut galaxy in terms of size).
On that page, the largest such energy event [wikipedia.org] is the estimate of energy released by a 10 billion solar mass black hole (estimate of course) over 100 million years. It's thought to be about 5 million solar masses of energy released and apparently hasn't disrupted the center of its galaxy (though that would a galaxy much more massive than the Milky Way).
So anyway, my point is twofold. First, disruption of a galaxy on this scale requires massive energy. Second, in the case of your nuclear bomb example, the mass of the bomb is much greater than the mass of the bomb which would be converted to energy when it is detonated. It's reasonable to expect the same to hold of any such galaxy-scale weapon. So in order for deployers of such a weapon to survive its use, they have to be well away from the weapon by the time it goes off. Either it's made onsite or it's moved there. The latter requires substantial propulsion. We know of no way to do that which doesn't leave evidence of its use.