Abstract
We present an interpretation of the time variability of the x-ray flux recently reported from a multiepoch campaign of 15 years of observations of the supernova remnant Cassiopeia A by Chandra. We show for the first time quantitatively that the [4.2–6] keV nonthermal flux increase up to 50% traces the growth of the magnetic field due to a vortical amplification mechanism at a reflection inward shock colliding with inner overdensities. The fast synchrotron cooling as compared with shock-acceleration time scale qualitatively supports the flux decrease.
- Received 24 January 2018
- Revised 30 April 2018
DOI:https://doi.org/10.1103/PhysRevLett.120.251101
© 2018 American Physical Society