Soft X-rays from the Cygnus Loop: Interpretation

Science  23 Apr 1971:
Vol. 172, Issue 3981, pp. 372-374
DOI: 10.1126/science.172.3981.372


Two possible interpretations of the recent soft x-ray observation of the Cygnus Loop are discussed. A synchrotron model requires a magnetic field less than 10-6 gauss and electron energies in excess of 1014 electron volts. These electrons must either have been reaccelerated or continuously injected into the source for about 50,000 years. The observations are also consistent with the radiation from a hot plasma having the cosmic abundances of the elements. A likely origin for the hot plasma is a blast wave produced by the explosion of a supernova in the interstellar medium. Fitting such a model to the observations implies a kinetic energy release in the explosion of 6x 1050 ergs for an assumed distance of 770 parsec.