The Heliotail: Theory and Modeling

[摘要] Physical processes are discussed related to the heliotail which is formed when the solar wind interacts with the local interstellar medium. Although astrotails are commonly observed, the heliotail observations are only indirect. As a consequence, the direct comparison of the observed astrophysical objects and the Sun is impossible. This requires proper theoretical understanding of the heliotail formation and evolution, and numerical simulations in sufficiently large computational boxes. In this paper, we review some previous results related to the heliotail flow and show new simulations which demonstrate that the solar wind collimation inside the Parker spiral field lines diverted by the heliopause toward the heliotail is unrealistic. On the contrary, solar cycle effects ensure that the solar wind density reaches its largest values near the solar equatorial plane. We also argue that a realistic heliotail should be very long to account for the observed anisotropy of 1-10 TeV cosmic rays.

[发布机构] Department of Space Science, University of Alabama in Huntsville, Huntsville; AL; 35805, United States^1

[关键词] Astrophysical objects;Computational box;Equatorial planes;Formation and evolutions;Local interstellar medium;Solar wind density;Solar-cycle effects;Theory and modeling