How do supernova remnants produce X-rays?
The combination of imaging and spectroscopic capabilities makes ASCA particularly suitable for the study of supernova remnants. In general, most X-rays that SNRs give off come from hot gas. As the SNR shock wave goes through interstellar space, it heats up the gas it plows into. This hot gas gives off X-rays via processes collectively known as thermal emission. In addition, a small amount of interstellar gas becomes trapped in the SNR shock and bounces back and forth across the shock, a process known as Fermi acceleration. The more times the electrons, protons, and ions from the gas bounce back and forth, the more energy they gain. Eventually, they become cosmic rays, which are subatomic particles (primarily electrons and protons) that travel in space near the speed of light. The emission given off when the cosmic ray electrons interact with the magnetic field is called synchrotron radiation. Synchrotron radiation, from cosmic rays each with an energy of about a billion electron volts
