Over four centuries after Tycho Brahe first observed the supernova that bears his name, the supernova remnant it created is still a bright source of X-rays. The supersonic expansion of the exploded star produced opposing shock waves, one moving outward into the surrounding interstellar gas and another moving back into the expanding stellar debris. This Chandra image of Tycho reveals the dynamics of the explosion’s interfering shock waves in detail. The outer shock has produced a rapidly moving shell of extremely high-energy electrons (blue), and the reverse shock has heated the expanding debris to millions of degrees (red and green). There is evidence from the Chandra data that the interference between these shock waves may be responsible for some of the ultra-energetic particles that pervade the Galaxy and constantly bombard the Earth as cosmic rays.

Image Credit: NASA