|A Hubble visible light image of the Crab Nebula inset against a full-sky gamma ray map showing the location of the nebula (croshairs). Credit: NASA|
To account for the observed emission, scientists say the electrons must have energies 100 times greater than can be achieved in any particle accelerator on Earth. This makes them the highest-energy electrons known to be associated with any cosmic source. Based on the rise and fall of gamma rays during the April outbursts, scientists estimate that the size of the emitting region must be comparable in size to the solar system.