Speaker
Description
Time variability of the X-ray flux of supernova remnants enables us to probe the evolution of the local magnetic field and the particle acceleration at interstellar shocks. High spatial resolution multiepoch (from 2000 to 2014) Chandra observations of Cassiopeia A supernova remnant have shown evidence of variation up to 50% of the 4.2-6 keV flux in six distinct regions located on the west side and toward the center of the remnant. We show that the [4.2-6] keV non-thermal flux increase traces the exponential growth of the magnetic field due to vortical amplification mechanism at reflection inward shocks colliding with inner outward clumps. The amplification occurs in the outer layer of the clumps where density gradient is non-vanishing (about 0.1 pc in this case). The fast synchrotron cooling as compared with shock-acceleration time scale qualitatively supports the flux decrease.
Keywords
Supernova remnants; magnetic field; X-ray emission
| Subcategory | Theoretical Results |
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