The evolution of Lithium: implications of a universal Spite plateau

Abstract

The cosmological {7Li problem consists in explaining why the primordial Li abundance, as predicted by the standard Big Bang nucleosynthesis theory with constraints from WMAP and Planck, is a factor of 3 larger than the Li abundance measured in the stars of the Spite plateau defined by old, warm dwarf stars of the Milky Way halo. Several explanations have been proposed to explain this difference, including various Li depletion processes as well as non standard Big Bang nucleosynthesis, but the main question remains unanswered. In this paper, we present detailed chemical evolution models for dwarf spheroidal and ultra faint galaxies, compute the galactic evolution of 7Li abundance in these objects and compare it with observations of similar objects. In our models, Li is mainly produced by novae and cosmic rays and to a minor extent by low and intermediate mass stars. We adopt the yield combination which best fits the Li abundances in the Milky Way stars. It is evident that the observations of dwarf objects define a Spite plateau, identical to that observed in the Milky Way, thus suggesting that the Spite plateau could be a universal feature and its meaning should be discussed. The predictions of our models for dwarf galaxies, are obtained by assuming as Li primordial abundance either the one detected in the atmospheres of the oldest halo stars (Spite plateau; A(Li)=2.2 dex), or the one from cosmological observations (WMAP; A(Li)=2.66 dex). Finally, we discuss the implications of the universality of the Spite plateau results.

7 pages, 4 figures

References in corpus (19)

• Nucleosynthetic signatures of the first stars
• The Quenching of the Ultra-Faint Dwarf Galaxies in the Reionization Era
• First stars VII. Lithium in extremely metal poor dwarfs
• TOPoS: II. On the bimodality of carbon abundance in CEMP stars. Implications on the early chemical evolution of galaxies
• Standard big bang nucleosynthesis and primordial CNO Abundances after Planck
• Ultra faint dwarfs: probing early cosmic star formation
• Super and massive AGB stars - III. Nucleosynthesis in metal-poor and very metal-poor stars - Z=0.001 and 0.0001
• Exploring the Origin of Lithium, Carbon, Strontium and Barium with four new Ultra Metal-Poor Stars
• The lowest detected stellar Fe abundance: The halo star SMSS J160540.18-144323.1
• From First Stars to the Spite Plateau: a Possible Reconciliation of Halo Stars Observations with Predictions from Big Bang Nucleosynthesis
• Discovery of ubiquitous lithium production in low-mass stars
• Back to the Lithium Plateau with J0023+0307 with [Fe/H]<-6
• Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era
• Chemical evolution of classical and ultra-faint dwarf spheroidal galaxies
• Chemical enrichment in very low-metallicity environments: Bootes I
• The GALAH Survey: A new constraint on cosmological lithium and Galactic lithium evolution from warm dwarf stars
• The AMBRE project: a study of Li evolution in the Galactic thin and thick discs
• Lithium and Beryllium in the Gaia-Enceladus Galaxy
• An equatorial ultra iron-poor star identified in BOSS

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• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• The Gaia-ESO Survey: Galactic evolution of lithium from iDR6
• Discovery of a thin lithium plateau among metal-poor red giant branch stars
• Detection of ${}^7$Be II in the Small Magellanic Cloud
• A coherent view of Li depletion and angular momentum transport to explain the Li plateau -- from Population II to Population I stars
• Lithium abundances as a tracer of AGB stars pollution in the globular cluster NGC 6752
• Evolution of lithium in the disc of the Galaxy and the role of novae
• The cosmological lithium problem
• Lithium evolution in the Galactic thin disc from Main-Sequence and early Red-Giant-Branch stars
• Modelling the chemical evolution of the Milky Way
• Gaia-Sausage-Enceladus: Lithium evolution from early red-giant-branch and main-sequence stars
• A Census of Sun's Ancestors and their Contributions to the Solar System Chemical Composition