Poster Abstracts

Name/Affiliation:  Arunas Kucinskas (Vilnius University, Lithuania)

Title:  OH infrared lines as indicators of oxygen abundance in the atmospheres of cool stars

We determine oxygen abundance in three extremely metal poor red giant stars, utilising for this purpose infrared OH lines. The analysis was performed using state-of-the-art 3D hydrodynamical model atmospheres and allowed us to obtain a good agreement between the oxygen abundances inferred from [OI] line at 630 nm and infrared OH lines. We briefly discuss the physical reasons that lead to different role of convection in the formation of [OI] and molecular lines, and provide further suggestions for the use of 3D hydrodynamical model atmospheres in the studies of extremely metal-poor stars.