The GALAH survey: a new constraint on cosmological lithium and Galactic lithium evolution from warm dwarf stars
Article
Article Title | The GALAH survey: a new constraint on cosmological lithium and Galactic lithium evolution from warm dwarf stars |
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ERA Journal ID | 41989 |
Article Category | Article |
Authors | Gao, Xudong (Author), Lind, Karin (Author), Amarsi, Anish M. (Author), Buder, Sven (Author), Bland-Hawthorn, Joss (Author), Campbell, Simon W. (Author), Asplund, Martin (Author), Casey, Andrew R. (Author), de Silva, Gayandhi M. (Author), Freeman, Ken C. (Author), Hayden, Michael R. (Author), Lewis, Geraint F. (Author), Martell, Sarah L. (Author), Simpson, Jeffrey D. (Author), Sharma, Sanjib (Author), Zucker, Daniel B. (Author), Zwitter, Tomaz (Author), Horner, Jonathan (Author), Munari, Ulisse (Author), Nordlander, Thomas (Author), Stello, Dennis (Author), Ting, Yuan-Sen (Author), Traven, Gregor (Author), Wittenmyer, Robert A. (Author) and Galah Collaboration, . (Author) |
Journal Title | Monthly Notices of the Royal Astronomical Society: Letters |
Journal Citation | 497 (1), pp. L30-L34 |
Number of Pages | 5 |
Year | 2020 |
Publisher | Oxford University Press |
Place of Publication | United Kingdom |
ISSN | 1745-3925 |
1745-3933 | |
Digital Object Identifier (DOI) | https://doi.org/10.1093/mnrasl/slaa109 |
Web Address (URL) | https://academic.oup.com/mnrasl/article/497/1/L30/5854574 |
Abstract | Lithium depletion and enrichment in the cosmos is not yet well understood. To help tighten constraints on stellar and Galactic evolution models, we present the largest high-resolution analysis of Li abundances A(Li) to date, with results for over 100000 GALAH (Galactic Archeology with HERMES) field stars spanning effective temperatures 5900K≲Teff≲7000K and metallicities −3 ≲ [Fe/H] ≲ +0.5. We separated these stars into two groups, on the warm and cool sides of the so-called Li dip, a localized region of the Kiel diagram wherein lithium is severely depleted. We discovered that stars in these two groups show similar trends in the A(Li)–[Fe/H] plane, but with a roughly constant offset in A(Li) of 0.4dex , the warm group having higher Li abundances. At [Fe/H]≳−0.5 , a significant increase in Li abundance with increasing metallicity is evident in both groups, signalling the onset of significant Galactic production. At lower metallicity, stars in the cool group sit on the Spite plateau, showing a reduced lithium of around 0.4dex relative to the primordial value predicted from big bang nucleosynthesis (BBN). However, stars in the warm group between [Fe/H] = −1.0 and −0.5 form an elevated plateau that is largely consistent with the BBN prediction. This may indicate that these stars in fact preserve the primordial Li produced in the early Universe. |
Keywords | stars: abundances; Galaxy: abundances; cosmology: primordial; nucleosynthesis; techniques: spectroscopic; stars: late-type; stars:; atmospheres; Astrophysics - Solar and Stellar Astrophysics; Astrophysics; - Cosmology and Nongalactic Astrophysics; Astrophysics - Astrophysics of; Galaxies |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
Public Notes | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society: Letters ©: 2020 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
Institution of Origin | University of Southern Queensland |
Byline Affiliations | Max Planck Society, Germany |
Australian National University | |
University of Sydney | |
Monash University | |
Macquarie University | |
University of New South Wales | |
University of Ljubljana, Slovenia | |
Centre for Astrophysics | |
INAF - Astronomical Observatory of Padova, Italy | |
Lund Observatory, Sweden | |
Computational Engineering and Science Research Centre | |
ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions, Australia |
https://research.usq.edu.au/item/q5x0q/the-galah-survey-a-new-constraint-on-cosmological-lithium-and-galactic-lithium-evolution-from-warm-dwarf-stars
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