Lithium-6 : Evolution from Big Bang to Present

Abstract

The primordial abundances of Deuterium, he4, and li7 are crucial to determination of the baryon density of the Universe in the framework of standard Big Bang nucleosynthesis (BBN). li6 which is only produced in tiny quantities and it is generally not considered to be a cosmological probe. However, recent major observational advances have produced an estimate of the li6/li7 ratio in a few very old stars in the galactic halo which impacts the question whether or not the lithium isotopes are depleted in the outer layers of halo stars, through proton induced reactions at the base of (or below) the convective zone. li6 is a pure product of spallation through the major production reactions, fast oxygen and alphas interacting on interstellar H, He (especially in the early Galaxy). The rapid nuclei are both synthesized and accelerated by SN II. In this context, the \li6 evolution should go in step with that of beryllium and boron, recently observed by the Keck and HST telescopes. Li6 adds a new constraint on the early spallation in the Galaxy. In particular, if confirmed, the Li6/Be9 ratio observed in two halo stars (HD 84937, BD +263578) gives strong boundary conditions on the composition and the spectrum of the rapid particles involved. We show that Li6 is essentially intact in halo stars, and a fortiori \li7. We can define a range of the Li6 abundance in the very early Galaxy consistent with Big Bang nucleosynthesis (5.6 10(-14) to 3. 10(-13) . Following the evolution at increasing metallicity, we explain the abundance in the solar system within a factor of about 2.

16 pages, 4 figures

References in corpus (7)

• Big-bang Nucleosynthesis Enters the Precision Era
• The Evolution of Li6 in Standard Cosmic-Ray Nucleosynthesis
• The Revival of Galactic Cosmic Ray Nucleosynthesis?
• Element Segregation in Low Metallicity Stars and the Primordial Lithium Abundance
• Nuclear Reaction Rates and Primordial ${}^6$Li
• Boron in Very Metal-Poor Stars
• The Age of the Universe

Cited by in corpus (56)

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• A Bitter Pill: The Primordial Lithium Problem Worsens
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• Did Something Decay, Evaporate, or Annihilate during Big Bang Nucleosynthesis?
• Big Bang Nucleosynthesis and Particle Dark Matter
• Radiative capture of nucleons at astrophysical energies with single-particle states
• Bound-State Effects on Light-Element Abundances in Gravitino Dark Matter Scenarios
• Lithium-6: A Probe of the Early Universe
• The Lithium Content of the Galactic Halo Stars
• Effects of Unstable Particles on Light-Element Abundances: Lithium versus Deuterium and He3
• Neutralinos, Big Bang Nucleosynthesis and 6Li in Low-Metallicity Stars
• Nucleosynthesis Constraints on a Massive Gravitino in Neutralino Dark Matter Scenarios
• Solving the Cosmic Lithium Problems with Gravitino Dark Matter in the CMSSM
• Bounds on long-lived charged massive particles from Big Bang nucleosynthesis
• Light Element Evolution and Cosmic Ray Energetics
• The Evolution of Li6 in Standard Cosmic-Ray Nucleosynthesis
• Big Bang Nucleosynthesis with Bound States of Long-lived Charged Particles
• The Revival of Galactic Cosmic Ray Nucleosynthesis?
• From First Stars to the Spite Plateau: a Possible Reconciliation of Halo Stars Observations with Predictions from Big Bang Nucleosynthesis
• Lithium-Beryllium-Boron : Origin and Evolution
• Abundances and Evolution of Lithium in the Galactic Halo and Disk
• Nuclear astrophysics: the unfinished quest for the origin of the elements
• On the baryometric status of He3
• Cosmic Ray Production of Lithium-6 by Structure Formation Shocks in the Early Milky Way: A Fossil Record of Dissipative Processes during Galaxy Formation
• Constraints on Omega_B from the nucleosynthesis of 7Li in the standard Big Bang
• Cosmological Cosmic Rays and the observed Li6 plateau in metal poor halo stars
• Testing Spallation Processes With Beryllium and Boron
• On Non-Primordial Deuterium Production by Accelerated Particles
• Atomic diffusion in metal-poor stars: II. Predictions for the Spite plateau
• Population III Generated Cosmic Rays and the Production of Li6
• A New Model for the Evolution of Light Elements in an Inhomogeneous Galactic Halo
• Implications of a new temperature scale for halo dwarfs on LiBeB and chemical evolution
• Gamow shell model description of radiative capture reactions ${}^6$Li$(p,\gamma )$${}^7$Be and ${}^6$Li$(n,\gamma )$${}^7$Li
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• On the Possible Sources of D/H Dispersion at High Redshift
• Cosmic Ray production of Beryllium and Boron at high redshift
• A low upper-limit on the lithium isotope ratio in HD140283
• Lithium-6 and Gamma Rays: Complementary Constraints on Cosmic-Ray History
• Cosmic rays, lithium abundance and excess entropy in galaxy clusters
• Probing Primordial and Pre-Galactic Lithium with High Velocity Clouds
• Cosmological Cosmic Rays: Sharpening the Primordial Lithium Problem
• Can Galactic Cosmic Rays Account for Solar 6Li Without Overproducing Gamma Rays?
• X-ray Clusters of Galaxies as Cosmological Tools
• Galactic Fly-Bys: New Source of Lithium Production
• LiBeB Production and Associated Astrophysical Sites
• Superbubbles as the source of 6Li, Be and B in the early Galaxy
• Evolution of Lithium-Beryllium-Boron and Oxygen in the early Galaxy
• An Enhanced Cosmological Li6 Abundance as a Potential Signature of Residual Dark Matter Annihilations
• Galactic Cosmic-Ray Induced Production of Lithium in the Small Magellanic Cloud
• Non-Thermal Cosmic Rays During Big Bang Nucleosynthesis to Solve the Lithium Problem
• Cosmic Ray Production of ${}^6$Li by Structure Formation Shocks in the Early Galaxy
• Big Bang Nucleosynthesis and Related Observations