4 ms·
I'm not sure why these high energies are unusual or unexpected. If I spray particles into a chaotic system, I would expect some tiny fraction of them to sling-
by mikhailfranco 3y ago
I'm not sure why these high energies are unusual or unexpected.
If I spray particles into a chaotic system, I would expect some tiny fraction of them to sling-shot around various attractive bodies, and some tiny fraction of those would be ejected to hit some other galaxy - like us.
It could be gravitational. Anything N>2 is unpredictable, with particles possibly exporting the total energy of the system, leaving everything else stationary (zero angular momentum, gently contracting). The same for electromagnetism.
Of course, there will be an occasional ultra-high-energy cosmic ray particle.
The only limit is the universal red-shift, which imposes a spectral shift on how far away this the particle could originate - but even then, it is just statistics, and it could be a 'lucky' high-energy escape from further away.
- eternityforest 3y agoWait, gravity has something to do with this? Like in the same manner as when NASA uses a gravity assist, or is this some other effect?
- maxnoe 3y agoGravity has nothing (directly) to do with acceleration of cosmic rays. You need vert strong magnetic or electric fields, preferably in shock fronts. https://en.m.wikipedia.org/wiki/Fermi_acceleration https://en.m.wikipedia.org/wiki/Fermi_acceleration Directly, I say, because the objects that are extreme enough to produce such environments are indeed essentially fueled by gravitation energy: supermassive black holes at the centers of galaxies, super nova explosions, colliding neutron stars, ... https://www.researchgate.net/figure/A-modern-adaption-of-the-so-called-Hillas-plot-from-8-It-displays-upper-limits-on_fig1_312374947 https://www.researchgate.net/figure/A-modern-adaption-of-the...