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The most energetic particles that strike us from space, which include neutrinos as well as gamma-ray photons and various other bits of subatomic shrapnel, i.e the cosmic rays are sometimes so energetic, that they must be born in cosmic accelerators fueled by cataclysms of staggering proportions... I have also read that Scientists suspect some sources: the Big Bang itself, shock waves from supernovas collapsing into black holes, and matter accelerated as it is sucked into massive black holes at the centers of galaxies..

Now I actually wanted to know from where these particles originate and how they attain such colossal energies?


marked as duplicate by honeste_vivere, ZeroTheHero, Pulsar, Kyle Kanos, Jon Custer May 16 '18 at 13:10

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The source of these UHCERs are active galactic nuclei, of energetic galaxies, powered by matter swirling into a supermassive black hole.

These rays should obey the GZK limit, 5*10^19eV. Though, there have been observations that contradict this limit, and the solutions are either that the source is nearby our galaxy or that the Lorentz covariance is violated.

The paradox could be solved by either:

-instrumental error

-local sources

-cosmic rays with heavier nuclei


Please see the whole article here:


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    $\begingroup$ When was the UHECR problem resolved? Last time I checked, we still did not know from where UHECRs arose. $\endgroup$ – honeste_vivere May 15 '18 at 11:59
  • $\begingroup$ I don't think it is resolved. There are several alternatives (AGNs, starburst galaxies, decay of massive DM particles, tidal disruption events, to name some). $\endgroup$ – anonymous Jul 27 at 3:16