Possible explanation for the galaxy's cosmic radiation

Cassiopeia A is a famous supernova remnant, the product of a gigantic explosion of a massive star about 350 years ago. Although discovered in radio observations 50 years ago, we now know that its emitted radiation spans from radio through high-energy gamma rays. It is also one of the few remnants for which the birth date and the type of supernova are known. It was a type IIb, the result of a core collapse supernova explosion. The precise knowledge of its nature makes Cassiopeia A one of the most