J/A+A/610/A38 Li enrichment histories of the thick/thin disc (Fu+, 2018)
The Gaia-ESO Survey:
Lithium enrichment histories of the Galactic thick and thin disc.
Fu X., Romano D., Bragaglia A., Mucciarelli A., Lind K., Delgado Mena E.,
Sousa S.G., Randich S., Bressan A., Sbordone L., Martell S., Korn A.J.,
Abia C., Smiljanic R., Jofre P., Pancino E., Tautvaisiene G., Tang B.,
Lanzafame A.C., Magrini L., Carraro G., Bensby T., Damiani F., Alfaro E.J.,
Flaccomio E., Morbidelli L., Zaggia S., Lardo C., Monaco L., Frasca A.,
Donati P., Drazdauskas A., Chorniy Y., Bayo A., Kordopatis G.
<Astron. Astrophys. 610, A38 (2018)>
=2018A&A...610A..38F 2018A&A...610A..38F (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, dwarfs ; Abundances
Keywords: stars: abundances - Galaxy: abundances - Galaxy: disc
Abstract:
Lithium abundance in most of the warm metal-poor main sequence stars
shows a constant plateau (A(Li)∼2.2dex) and then the upper envelope
of the lithium vs. metallicity distribution increases as we approach
solar metallicity. Meteorites, which carry information about the
chemical composition of the interstellar medium at the solar system
formation time, show a lithium abundance A(Li)∼3.26dex. This pattern
reflects the Li enrichment history of the interstellar medium during
the Galaxy lifetime. After the initial Li production in Big Bang
Nucleosynthesis, the sources of the enrichment include AGB stars,
low-mass red giants, novae, type II supernovae, and Galactic cosmic
rays. The total amount of enriched Li is sensitive to the relative
contribution of these sources. Thus different Li enrichment histories
are expected in the Galactic thick and thin disc. We investigate the
main sequence stars observed with UVES in Gaia-ESO Survey iDR4 catalog
and find a Li-[alpha/Fe] anticorrelation independent of [Fe/H], Teff,
and log(g). Since in stellar evolution different α enhancements
at the same metallicity do not lead to a measurable Li abundance
change, the anticorrelation indicates that more Li is produced during
the Galactic thin disc phase than during the Galactic thick disc
phase. We also find a correlation between the abundance of Li and
s-process elements Ba and Y, and they both decrease above the solar
metallicity, which can be explained in the framework of the adopted
Galactic chemical evolution models.
Description:
To investigate the Galactic lithium enrichment history we se- lect
well-measured main sequence field stars with UVES spectra from the
GES iDR4 catalogue. In our selection, 1884 UVES stars are marked as
field stars, including those of the Galactic disc and halo designated
as MW (GE_MW) fields, standard CoRoT (GE_S D_CR) field, standard
radial velocity (GE_S D_RV) field, and stars to the Galactic Bulge
direction (GEMWBL).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 130 1399 Stellar parameters, the selected chemical
abundances, and their corresponding
uncertainties of stars in our final sample
--------------------------------------------------------------------------------
See also:
J/A+A/574/L7 : Gaia-ESO Survey: Li-rich stars in NGC2547 (Sacco+, 2015)
J/A+A/598/A5 : Gaia-ESO Survey iDR4 calibrators (Pancino+, 2017)
J/A+A/601/A112 : GES iDR4 Mg-Al anticorrelation in GCs (Pancino+, 2017)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- CName Name derived from the object's equatorial
coordinate (HHMMSSss+DDMMSSs)
18- 43 A26 --- Star Object name
45- 48 F4.2 [Sun] ALiLTE LTE Li abundance from GES iDR4
50- 53 F4.2 [Sun] e_ALiLTE ? Uncertainty of LTE Li abundance
55- 58 F4.2 [Sun] ALiNLTE NLTE Li abundance
60- 67 A8 --- CatLi Li abundance category (1)
69- 73 F5.2 [Sun] [alpha/Fe] Mean value of [alpha/Fe] from MCMC
75- 78 F4.2 [Sun] e_[alpha/Fe] 1sigma uncertainty of [alpha/Fe] from MCMC
80- 84 F5.2 [Sun] [Fe/H] Iron abundance from GES iDR4 catalogue
86- 89 F4.2 [Sun] e_[Fe/H] Uncertainty of [Fe/H]
91- 94 F4.2 [Sun] logg Surface gravity from GES iDR4
96- 99 F4.2 [Sun] e_logg Uncertainty of log(g)
101-104 I4 K Teff Effective temperature from GES iDR4
106-108 I3 K e_Teff Uncertainty of Teff
110-114 F5.2 [Sun] [Ba/Fe] Mean value of [Ba/Fe] from MCMC
116-119 F4.2 [Sun] e_[Ba/Fe] 1sigma uncertainty of [Ba/Fe] from MCMC
121-125 F5.2 [Sun] [Y/Fe] Mean value of [Y/Fe] from MCMC
127-130 F4.2 [Sun] e_[Y/Fe] 1sigma uncertainty of [Y/Fe] from MCMC
--------------------------------------------------------------------------------
Note (1): Li abundance category flag as follows:
meas. = checked Li measurement
La.upper = labeled upper limits
--------------------------------------------------------------------------------
Acknowledgements:
Xiaoting Fu, xiaoting.fu(at)oabo.inaf.it
(End) Xiaoting Fu [Unibo & INAF-OABO, Italy], Patricia Vannier [CDS] 16-Nov-2017