Be and O in the ultra metal-poor dwarf 2MASS J18082002-5104378: The Be-O correlation

Abstract

Measurable amounts of Be could have been synthesised primordially if the Universe were non-homogeneous or in the presence of late decaying relic particles. We investigate the Be abundance in the extremely metal-poor star 2MASS J1808-5104 ([Fe/H]=--3.84) with the aim of constraining inhomogeneities or the presence of late decaying particles. High resolution, high signal-to-noise ratio UV spectra were acquired at ESO with the Kueyen 8.2 m telescope and the UVES spectrograph. Abundances were derived using several model atmospheres and spectral synthesis code. We measured log(Be/H) = -14.3 from a spectrum synthesis of the region of the Be line. Using a conservative approach, however we adopted an upper limit two times higher, i.e. log(Be/H) < -14.0. We measured the O abundance from UV OH lines and find [O/H]=--3.46 after a 3D correction. Our observation reinforces the existing upper limit on primordial Be. There is no observational indication for a primordial production of Be. This places strong constraints on the properties of putative relic particles. This result also supports the hypothesis of a homogeneous Universe, at the time of nucleosynthesis. Surprisingly, our upper limit of the Be abundance is well below the Be measurements in stars of similar [O/H]. This may be evidence that the Be-O relation breaks down in the early Galaxy, perhaps due to the escape of spallation products from the gas clouds in which stars such as 2MASS J1808-5104 have formed.

9 pages, 9 Figures

References in corpus (16)

• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• Big Bang Nucleosynthesis Constraints on Hadronically and Electromagnetically Decaying Relic Neutral Particles
• Gaia Data Release 1: Catalogue validation
• Three-dimensional mapping of the local interstellar medium with composite data
• TOPoS: II. On the bimodality of carbon abundance in CEMP stars. Implications on the early chemical evolution of galaxies
• HE 1327-2326, an unevolved star with [Fe/H]<-5.0. II. New 3D-1D corrected abundances from a VLT/UVES spectrum
• NLTE determination of the aluminium abundance in a homogeneous sample of extremely metal-poor stars
• NLTE determination of the sodium abundance in a homogeneous sample of extremely metal-poor stars
• The forbidden 1082 nm line of sulphur: the photospheric abundance of sulphur in the Sun and 3D effects
• UVES radial velocity accuracy from asteroid observations. Implications for the fine structure constant variability
• Beryllium abundances in metal-poor stars
• G64-12 and G64-37 are Carbon-Enhanced Metal-Poor Stars
• Effect of Long-lived Strongly Interacting Relic Particles on Big Bang Nucleosynthesis
• An in-depth spectroscopic examination of molecular bands from 3D hydrodynamical model atmospheres. II. Carbon-enhanced metal-poor 3D model atmospheres
• Primordial beryllium as a big bang calorimeter
• Beryllium in Ultra-Lithium-Deficient Halo Stars - The Blue Straggler Connection

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