The galactic lithium evolution revisited

The evolution of the Li-7 abundance in the Galaxy has been computed by mean s of the two-infall model of Galactic chemical evolution. We took into acco unt several stellar Li-7 sources: novae, massive AGE stars, C-stars and Typ e II SNe, In particular, we adopted new theoretical yields for novae. We al so took into account the Li-7 production from GCRs, In particular, the abso lute yields of Li-7, as suggested by a recent reevaluation of the contribut ion of GCR spallation to the Li-7 abundance, have been adopted. We compared our theoretical predictions for the evolution of Li-7 abundance in the solar neighborhood with a new compilation of data, where we identif ied the population membership of the stars on a kinematical basis, A critic al analysis of extant observations revealed a possible extension of the Li- 7 plateau towards higher metallicities (up to [Fe/H] similar to -0.5 or eve n -0.3) with a steep rise afterwards. We conclude that 1) the Li-7 contribution from novae is required in order t o reproduce the shape of the growth of A(Li) versus [Fe/H], 2) the contribu tion from Type II SNe should be lowered by at least a factor of two, and 3) the Li-7 production from GCRs is probably more important than previously e stimated, in particular at high metallicities: by taking into account GCR n ucleosynthesis we noticeably improved the predictions on the Li-7 abundance in the presolar nebula and at the present time as inferred from measures i n meteorites and T Tauri stars, respectively. We also predicted a lower lim it for the present time Li-7 abundance expected in the bulge, a prediction which might be tested by future observations.