Lithium in the Galaxy: current status and contribution from the low-mass giants?

Abstract

We discuss the evolution of Li in the Galaxy based on a large sample of dwarfs and giants collected from the cross-match of the Gaia and GALAH surveys. Data spans a wide range in metallicity and cover various Galactic evolutionary phases. Metal-poor dwarfs with [Fe/H] < -0.8 dex are found to have constant mean A(Li) = 2.2 dex with standard deviation of 0.14 dex but with a very slightly increasing trend with increase in metallicity. However, in the sub-solar metallicity range (-0.8 < [Fe/H] < 0 dex), Li has increased significantly from the initial value of about 2.2 dex to the present value of about 3.3 dex. However, in supersolar metallicity stars, Li is found to be decreasing with increasing metallicity. We also discuss briefly about a rare class of so called Li-rich low-mass giants as one of the promising candidate for Li enrichment in the Galaxy