Lithium abundances in microlensed bulge dwarfs

DOI

Lithium abundances are presented for 91 dwarf and subgiant stars in the Galactic bulge. The analysis is based on line synthesis of the ^7^Li line at 6707{AA} in high-resolution spectra obtained during gravitational microlensing events, when the brightnesses of the targets were highly magnified. Our main finding is that bulge stars at sub-solar metallicities that are older than about eight billion years do not show any sign of Li production; that is, the Li trend with metallicity is flat or even slightly declining. This indicates that no lithium was produced during the first few billion years in the history of the bulge. This finding is essentially identical to what is seen for the (old) thick disk stars in the solar neighbourhood, and adds another piece of evidence for a tight connection between the metal-poor bulge and the Galactic thick disk. For the bulge stars younger than about eight billion years, the sample contains a group of stars at very high metallicities at [Fe/H]~=+0.4 that have lithium abundances in the range A(Li)=2.6-2.8. In the solar neighbourhood the lithium abundances have been found to peak at A(Li)~=3.3 at [Fe/H]~=+0.1 and then decrease by 0.4-0.5dex when reaching [Fe/H]~=+0.4. The few bulge stars that we have at these metallicities seem to support this declining A(Li) trend. This could indeed support the recent claim that the low A(Li) abundances at the highest metallicities seen in the solar neighbourhood could be due to stars from the inner disk, or the bulge region, that have migrated to the solar neighbourhood.

Cone search capability for table J/A+A/634/A130/table1 (Li abundances and uncertainties)

Identifier
DOI http://doi.org/10.26093/cds/vizier.36340130
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/634/A130
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/634/A130
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/634/A130
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/A+A/634/A130
Provenance
Creator Bensby T.; Feltzing S.; Yee J.; Johnson J.A.; Gould A.; Asplund M.,Melendez J.; Lucatello S.
Publisher CDS
Publication Year 2020
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Galactic and extragalactic Astronomy; Interdisciplinary Astronomy; Natural Sciences; Physics; Stellar Astronomy