Cosmic Ray Production of $^6$Li by Structure Formation Shocks in the Early Galaxy

Abstract

We discuss the production of the element $^6$Li in the early Galaxy by cosmic rays accelerated at structure formation shocks, driven by the hierarchical merging of sub-Galactic halos during Galaxy formation. The salient features of this scenario are discussed and compared with observations of $^6$Li in metal-poor halo stars, including a recent Subaru HDS result on the star HD140283. Some unique predictions of the model are clearly testable by future observations and may also provide important insight into how the Galaxy formed.Comment: 4 pages, 1 figure; to appear in Nuc. Phys. A; talk at Nuclei in the Cosmos 7, Fuji-Yoshida, Japan 200