Abstract
AbstractWe present the largest sample available to date of lithium abundances in extremely metal poor (EMP) Halo dwarfs. Four Teff estimators are used, including IRFM and Hα wings fitting against 3D hydrodynamical synthetic profiles. Lithium abundances are computed by means of 1D and 3D-hydrodynamical NLTE computations. Below [Fe/H]~−3, a strong positive correlation of A(Li) with [Fe/H] appears, not influenced by the choice of the Teff estimator. A linear fit finds a slope of about 0.30 dex in A(Li) per dex in [Fe/H], significant to 2–3 σ, and consistent within 1 σ among all the Teff estimators. The scatter in A(Li) increases significantly below [Fe/H]~−3. Above, the plateau lies at 〈A(Li)3D, NLTE〉 = 2.199 ± 0.086. If the primordial A(Li) is the one derived from standard Big Bang Nucleosynthesis (BBN), it appears difficult to envision a single depletion phenomenon producing a thin, metallicity independent plateau above [Fe/H] = −2.8, and a highly scattered, metallicity dependent distribution below.
Highlights
In this work we present lithium abundances for a sample of 28 stars in the −3.6
We employed four temperature scales: Hα wings fitting against a grid of synthetic profiles from 1D models using Barklem et al (2000) or Ali & Griem (1966) self-broadening theories (BA and ALI scales); Hα fitting against a 3D-hydrodynamical grid based on CO5BOLD models (Freytag et al 2002, Wedemeyer et al 2004) with Barklem et al (2000) self-broadening (3D scale); InfraRed Flux method (IRFM, Gonzalez Hernandez & Bonifacio 2009)
Results up to 400 K difference in Teff exist between the coolest scale (BA) and the hottest (ALI and IRFM), the results are remarkably similar
Summary
1. Introduction In this work we present lithium abundances for a sample of 28 stars in the −3.6
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Proceedings of the International Astronomical Union
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
