Charged electrons (and positrons, their antiparticle counterparts) make up only about one percent of cosmic rays, so they’re hard to spot among the background noise of other particles. For the new study, the researchers used new algorithms to more accurately identify them from the HESS data set. The effort revealed a never-before-seen spectrum of higher-energy cosmic ray electrons of the order of 40 TeV.
Tracing the source of cosmic ray electrons is difficult; Because their path bends towards us as they pass through the magnetic fields in the universe. So when they reach us, they could have come from anywhere.
The farther the electron travels, the less energy it will bring to earth
The direction may be uncertain, but astronomers can at least know how far the electrons have traveled. The more these energetic particles move through space, the more energy they lose. Hence, the research team says that the majority of electrons with energies below one TeV probably came from a cluster of distant bodies.
But those at the lower end of the spectrum could not have traveled very far to have that amount of energy. The team calculated that these electrons must have come from a source several thousand light-years away from our solar system. On a cosmic scale, this distance is really close.
The research team says the most obvious candidate for the electrons is a “pulsar”; A type of neutron star that emits electromagnetic radiation from its poles. It is possible that one or several pulsars at a short distance are responsible for the production of these rays.
The researchers’ findings have been published in the journal Physical Review Letters.
