The highest-energy particles in the Universe, known as galactic cosmic rays, have always puzzled scientists. The particles' source must be within 200 million light years of Earth, because cosmic rays from beyond this distance would lose energy as they traveled through cosmic microwave radiation. It has been uncertain what kinds of objects within this distance could generate such energetic particles.

Answer: "retired" quasars - galaxies containing supermassive black holes that now appear lifeless

"Each contains a central black hole of at least 100 million solar masses that, if spinning, could form a colossal battery sending atomic particles, like sparks, shooting off towards Earth at near-light speed,"

BUT WAIT! They come from supernovas.....