The metal-poor end of the Spite plateau
Luca Sbordone
(1)
,
Piercarlo Bonifacio
(1, 2, 3)
,
Elisabetta Caffau
(2, 3)
,
Hans-Günter Ludwig
(1, 2, 3)
,
Natalie Behara
(1, 2, 3)
,
J. I. Gonzalez-Hernandez
(1, 2, 3)
,
Matthias Steffen
(4)
,
Roger Cayrel
(2, 3)
,
Bernd Freytag
(5)
,
C. Van'T Veer
(2, 3)
,
Paolo Molaro
(6)
,
Bertrand Plez
(7)
,
Thirupathi Sivarani
(8)
,
Monique Spite
(2, 3)
,
François Spite
(2, 3)
,
Timothy C. Beers
(9)
,
Norbert Christlieb
(4)
,
Patrick François
(2, 3)
,
Vanessa Hill
(10, 2, 3)
1
CIFIST -
Cosmological Impact of the First Stars
2 GEPI - Galaxies, Etoiles, Physique, Instrumentation
3 Physique stellaire et galactique
4 ESO - European Southern Observatory
5 CRAL - Centre de Recherche Astrophysique de Lyon
6 INFN - Istituto Nazionale di Fisica Nucleare, Sezione di Roma La Sapienza
7 UM2 - Université Montpellier 2 - Sciences et Techniques
8 Indian Institute of Astrophysiscs, Bangalore - India
9 Michigan State University
10 Observatoire de la Côte d'Azur
2 GEPI - Galaxies, Etoiles, Physique, Instrumentation
3 Physique stellaire et galactique
4 ESO - European Southern Observatory
5 CRAL - Centre de Recherche Astrophysique de Lyon
6 INFN - Istituto Nazionale di Fisica Nucleare, Sezione di Roma La Sapienza
7 UM2 - Université Montpellier 2 - Sciences et Techniques
8 Indian Institute of Astrophysiscs, Bangalore - India
9 Michigan State University
10 Observatoire de la Côte d'Azur
Elisabetta Caffau
- Fonction : Auteur
- PersonId : 772584
- ORCID : 0000-0001-6011-6134
- IdRef : 14550266X
Patrick François
- Fonction : Auteur
- PersonId : 1294615
- ORCID : 0000-0001-8698-2217
Résumé
We present the largest sample available to date of lithium abundances in extremely metal poor (EMP) Halo dwarfs. Four T<SUB>eff</SUB> estimators are used, including IRFM and Halpha 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 sigma, and consistent within 1 sigma among all the T<SUB>eff</SUB> estimators. The scatter in A(Li) increases significantly below [Fe/H]~-3. Above, the plateau lies at = 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.