Acceleration of cosmic rays by supernova
Posted: Sun Mar 27, 2011 8:40 pm
The Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics, PAMELA, has been measuring cosmic rays for the past three years. The origin of cosmic rays from supernova is now being disputed. Cosmic rays are actually fast-moving particles that carryan extraordinary amount of energy and continuously bombard Earth from every direction.
The current theory is that supernovae should accelerate both hydrogen and helium in the same way. But PAMELA has found diffeences between measurements of the hydrogen and helium particles that a single shock wave cannot explain. The two particles seem to accelerated by different mechanisms.
My question is very basic. Why does hydrogen and helium particles have to be accelerated by the same mechanism ? Could not a supernova have explosions at different times that eject the hydrogen envelop and then the helium envelop ? These two explosions would happen close together in cosmic time but could have different amounts of energy.
3/27/2011
The current theory is that supernovae should accelerate both hydrogen and helium in the same way. But PAMELA has found diffeences between measurements of the hydrogen and helium particles that a single shock wave cannot explain. The two particles seem to accelerated by different mechanisms.
My question is very basic. Why does hydrogen and helium particles have to be accelerated by the same mechanism ? Could not a supernova have explosions at different times that eject the hydrogen envelop and then the helium envelop ? These two explosions would happen close together in cosmic time but could have different amounts of energy.
3/27/2011