- University of California, Los Alamos Scientific Laboratory, Los Alamos, New Mexico 87544 U.S.A.
The supersonic flow of the solar wind is believed to terminate in a shock transition to subsonic flow somewhere in the outer part of the solar system. The radius of the roughly spherical region (the heliosphere) bounded by this standing shock wave has been estimated as ~20 A.U. as the result of a theoretical study by Patterson, Johnson, and Hanson of the distribution of interplanetary neutral hydrogen. The present paper describes a model of particle densities in the region beyond the heliosphere. It is shown on the basis of this model that most of the neutral hydrogen in the vicinity of the Earth does not originate (in charge exchanges between solar wind protons and interstellar neutral hydrogen) near the shock boundary of the heliosphere, as assumed by Patterson, Johnson, and Hanson, but in a Shell far beyond the shock. The neutral hydrogen density near the Earth can then be maintained only if the shock is near 5 A.U. This reduced value for the radius of the heliosphere implies an interstellar magnetic field larger by an order of magnitude than that conventionally accepted. It is, however, in good agreement with recent estimates of the size of this region based on the solar modulation of galactic cosmic rays.
- 1 - natural sciences ; 2 - physics & astronomy ; 3 - astronomy & astrophysics
- 1 - sciences appliquees, technologies et medecines ; 2 - sciences exactes et technologie ; 3 - terre, ocean, espace ; 4 - geophysique externe
- 1 - Physical Sciences ; 2 - Earth and Planetary Sciences ; 3 - Space and Planetary Science
- 1 - Physical Sciences ; 2 - Physics and Astronomy ; 3 - Astronomy and Astrophysics