Cosmic-ray propagation in the Galaxy

Journal Article · Sat May 01 00:00:00 EDT 1976 · Sov. Astron. AJ (Engl. Transl.); (United States)

OSTI ID:7240251

Bychkov, K V

The time required for cosmic rays to leave the magnetic field lines of a source and reach the lines of the general galactic field is shown to be very long, as exemplified by supernova remnants. A '' convective'' model for cosmic-ray propagation in the Galaxy is proposed, whereby most cosmic rays would travel by remaining frozen into closed ''traps'' formed by the magnetic field of the source. A discussion is given of processes inducing the formation of such traps at various phases in the development of a supernova remnant, and of the stability of the traps. The survival time of traps in the Galaxy may be much longer than the corresponding diffusion time for an individual particle, thereby substantially reducing the excessive demands on the power of the sources entailed by the customary cosmic-ray diffusion model. The convective model is consistent with the available observational data on diffuse radio waves and ..gamma.. rays; the spectrum, chemical composition, and isotropy of the cosmic rays recorded at the earth; and radioactive elements and tracks in rocks and meteorites. The increased slope of the cosmic-ray spectrum observed in the energy range E/sub tr/= (1--10) x 10/sup 15/ eV is attributable to the fact that the Larmor gyroradius of particles with an energy E>E/sub tr/ becomes comparable to the size of the traps. As a result such particles will escape from the traps and diffuse out of the galactic disk sooner than would be the case if they remained trapped. The chemical composition of cosmic rays with energies on either side of E/sub tr/ should differ, and there should be increased anisotropy for E>E/sub tr/. The value of E/sub tr/ should itself increase with the charge of the nuclei. A search program is suggested for traps around young and old supernova remnants. (AIP)

• Research Organization: Special Astrophysical Observatory, USSR Academy of Sciences
• OSTI ID: 7240251
• Journal Information: Sov. Astron. AJ (Engl. Transl.); (United States), Vol. 20:3
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
MILKY WAY
COSMIC RAY PROPAGATION
ANISOTROPY
CHEMICAL COMPOSITION
CONVECTION
COSMIC ELECTRONS
INTERSTELLAR SPACE
MAGNETIC FIELDS
PLASMA
SUPERNOVA REMNANTS
SUPERNOVAE
COSMIC RADIATION
COSMIC RADIO SOURCES
ELECTRONS
ELEMENTARY PARTICLES
ENERGY TRANSFER
FERMIONS
GALAXIES
HEAT TRANSFER
IONIZING RADIATIONS
LEPTONS
RADIATIONS
SPACE
STARS
640101* - Astrophysics & Cosmology- Cosmic Radiation