Supernova envelope shock origin of cosmic rays - a review
The hydrodynamic shock origin of cosmic rays in the envelope of a Type I presupernova star is reviewed. The spectrum produced by the relativistic hydrodynamic shock is one power of E steeper than observed and so is unlikely to be the primary source of cosmic rays. On the other hand the possibility of accelerating ultrahigh energy particles to greater than or equal to 10/sup 18/ eV is unique to the shock mechanism and currently no other suggested galactic or extragalactic site is likely. The heavy nuclei are partially spalled in the shock transition and partially resynthesized in the postshock expansion for E less than or equal to 10/sup 15/ eV dependent upon the large number of pairs in the post-shock fluid. Above this energy the shock progresses in the magnetized photosphere. The high energy limit is similarly ordered 10/sup 21/ eV due to the coronal density of the presupernova star. The objection to SN shock accelerated cosmic rays by adiabatic deceleration is questioned on the basis of the Alfven wave scattering conditions. Ultrahigh energy particles escape because the wave excitation energy density is too low in the dimension of many Larmor radii necessary for scattering back to the SN remnant. Others escape if the energy density is too high. For all others between these two limits the immediately following matter of lower velocity and greater mass compresses and energizes previously trapped higher energy particles, allowing them to escape at energies still higher than originally shock ejected from the supernova.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- OSTI ID:
- 5404215
- Journal Information:
- Adv. Space Res.; (United States), Vol. 4:2-3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
SUPERNOVAE
STAR MODELS
ALFVEN WAVES
CHARGED PARTICLES
ENERGY SPECTRA
HYDRODYNAMICS
NUCLEOSYNTHESIS
SCATTERING
SHOCK WAVES
ERUPTIVE VARIABLE STARS
FLUID MECHANICS
HYDROMAGNETIC WAVES
MATHEMATICAL MODELS
MECHANICS
SPECTRA
STARS
SYNTHESIS
VARIABLE STARS
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
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