J/A+A/690/A97 AMBRE catalogue of lead abundances (Contursi+, 2024)
The AMBRE Project: Lead abundance in Galactic stars.
Contursi G., de Laverny P., Recio-Blanco A., Molero M., Spitoni E.,
Matteucci F., Cristallo S.
<Astron. Astrophys. 690, A97 (2024)>
=2024A&A...690A..97C 2024A&A...690A..97C (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, late-type ; Abundances ; Optical ; Ultraviolet
Keywords: stars: abundances - stars: AGB and post-AGB - Galaxy: abundances -
Galaxy: disk - Galaxy: evolution - Galaxy: stellar content
Abstract:
The chemical evolution of neutron capture elements in the Milky Way is
still a matter of debate. Although more and more
studies investigate their chemical behaviour, there is still a lack of
a significant large sample of abundances of a key heavy element: lead.
Lead is the final product of the s-process nucleosynthesis channel and
is one of the most stable heavy elements. The goal of this article is
to present the largest catalogue of homogeneous Pb abundances, in
particular for metallicities higher than -1.0dex, and then to study
the lead content of the Milky Way.
We analysed high-resolution spectra from the ESO UVES and FEROS
archives. Atmospheric parameters were taken from the AMBRE
parametrisation. We used the automated abundance method GAUGUIN to
derive LTE and NLTE lead abundances in 653 slow-rotating FGK-type
stars from the 368.34nm PbI line, with metallicities ranging from
-2.9 to 0.6 ex Within this sample, no lead-enhanced Asymptotic Giant
Branch (AGB) stars were found, but nine lead-enhanced metal-poor stars
([Pb/Fe]>1.5) were detected. Most of them were already identified as
carbon-enhanced metal-poor stars with enrichments in other s-process
species. The lead abundance of 13 Gaia Benchmark Stars are also
provided. We then investigated the Pb content of the Milky Way disc by
computing vertical and radial gradients and found a slightly
decreasing [Pb/Fe] radial trend with metallicity. This trend together
with other related ratios ([Pb/Eu], [Pb/Ba], and [Pb/alpha]) are
interpreted thanks to chemical evolution models. The two-infall model
closely reproduces the observed trends with respect to the
metallicity. It is also found that the AGB contribution to the Pb
Galactic enrichment has to be strongly reduced. Moreover, the
contribution of massive stars with rather high rotational velocities
should be favoured in the low-metallicity regime.
Description:
Catalogue of AMBRE/lead abundances derived thanks to the automated
abundance method GAUGUIN. The reported A(Pb) values are the median of
the A(Pb) Monte-Carlo distributions.
The AQ_16 and AQ_84 correspond to the 16th and 84th quantiles of these
distributions, respectively, and are thus related to the associated
uncertainties.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table4.dat 160 650 AMBRE catalogue of lead abundances
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [0/694] Sequential number
5- 32 A28 --- Name Star name
34- 36 I3 --- Nspec Number of analysed repeat spectra
38- 44 F7.2 K Teff Effective temperature (or mean if Nspec>1)
46- 49 F4.2 [cm/s2] logg Stellar surface gravity in log scale
(or mean if Nspec>1)
51- 55 F5.2 [-] [Fe/H] Stellar mean metallicity
(or mean if Nspec>1)
57- 61 F5.2 [-] [alpha/Fe] ? Abundances ratio [alpha/Fe]
(or mean if Nspec>1)
63- 81 F19.16 --- A(Pb)LTE LTE lead abundance
83-101 F19.16 --- A(Pb)NLTE Non-LTE lead abundance
103-121 F19.16 --- e_A(Pb)LTE []? Lower uncertainty associated to
A(Pb)LTE (A_Q16)
123-141 F19.16 --- E_A(Pb)LTE []? Upper uncertainty associated
to A(Pb)LTE (A_Q84)
143-160 F18.16 --- DeltaPb Quadratic sum of errors caused by
atmospheric parameters uncertainties
--------------------------------------------------------------------------------
Acknowledgements:
Patrick de Laverny, patrick.de_laverny(at)oca.eu
(End) Patricia Vannier [CDS] 10-Sep-2024