Novae contribution to the galactic lithium enhancement

Abstract

We use the Modules for Experiments in Stellar Astrophysics (MESA) code to calculate the yields of 7Li in the ejecta of classical novae, occurring on the surface of carbon-oxygen (CO) and oxygen-neon-magnesium (ONeMg) white dwarfs (WDs). Taking the masses and the mass accretion rates of WDs as input parameters, this article presents a grid showing the yield of 7Li from classical novae, including a total of 79 models. Under similar input parameters, the 7Li yields in our models are consistent with previous ones in the literature. 7Li yields recently inferred spectroscopically from classical nova V1369 Cen are then compared with the theoretical values obtained in this work. Using the grid as its basis and population synthesis as its method, this paper estimates the amount of 7Li produced by classical novae compared to the total 7Li in the Galaxy. Our simulations suggest that novae can eject about 10-9M⊙ of 7Li every year. Hence, one may estimate that approximately 10% of 7Li in the Galaxy originates from classical novae, which is significantly higher than the 7Li produced by asymptotic giant branch stars.