J/A+A/663/A125 AMBRE catalogue of stellar [Mg/Fe] and ages (Palla+, 2022)
[Mg/Fe] ratios in the solar neighbourhood:
Stellar yields and chemical evolution scenarios.
Palla M., Santos-Peral P., Recio-Blanco A., Matteucci F.
<Astron. Astrophys. 663, A125 (2022)>
=2022A&A...663A.125P 2022A&A...663A.125P (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, nearby ; Abundances ; Spectroscopy ;
Stars, ages ; Optical
Keywords: Galaxy: abundances - Galaxy: disk - Galaxy: evolution -
nuclear reactions, nucleosynthesis, abundances
Abstract:
The [Mg/Fe] abundance ratios are a fundamental fossil signature used
to trace the chemical evolution of the disc and to divide it into
low-α and high-α populations. Despite the huge
observational and theoretical efforts, discrepancies between models
and data are still present and several explanations have been put
forward to explain the [α/Fe] bimodality.
In this work we take advantage of a new AMBRE:HARPS dataset, which
provides new more precise [Mg/Fe] estimations and reliable stellar
ages for a subsample of stars, to study the [α/Fe] bimodality
and the evolution of the solar neighbourhood.
The data are compared with detailed chemical evolution models for the
Milky Way, exploring the most used prescriptions for stellar yields
and different formation scenarios for the Galactic disc (i.e. the
delayed two-infall and the parallel models), including prescriptions
for stellar radial migration.
We see that most of the stellar yield prescriptions struggle to
reproduce the observed trend of the data and that semi-empirical
yields describe best the [Mg/Fe] evolution in the thick and thin
discs. In particular, most of the yields still predict a steeper
decrease of the [Mg/Fe] ratio at high metallicity than shown by the
data.The bulk of the data are well reproduced by the parallel and
two-infall scenarios, but both scenarios have problems in explaining
the most metal-rich and metal-poor tails of the low-α data.
These tails can be explained in light of radial migration from the
inner and outer disc regions, respectively.
Despite the evidence of stellar migration, it is difficult to estimate
the actual contribution of stars from other parts of the disc to the
solar vicinity in the data we adopt. However, the comparison between
data and models suggests that peculiar histories of star formation,
such as that of the two-infall model, are still needed to reproduce
the observed distribution of stars.
Description:
We present Mg abundances derived using and optimised normalisation
procedure for selected stars from the AMBRE Project (Santos-Peral et
al., 2020A&A...639A.140S 2020A&A...639A.140S). For the subsample of main sequence turn-off
stars, we present stellar ages estimated by fitting PARSEC isochrones
(Santos-Peral et al., 2021A&A...653A..85S 2021A&A...653A..85S).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
mgfe-age.dat 68 1065 [M/H], [Mg/Fe] for stars of Santos-Peral et al.
(2020A&A...639A.140S 2020A&A...639A.140S)) Ages for stars in
Santos-Peral et al. (2021A&A...653A..85S 2021A&A...653A..85S)
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Byte-by-byte Description of file: mgfe-age.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR2 Gaia DR2 ID
21- 26 F6.3 [-] [M/H] Mean stellar metallicity (1)
28- 31 F4.2 [-] e_[M/H] Error associated to metallicity
33- 46 F14.11 [-] [Mg/Fe] Magnesium abundance
48- 59 F12.10 [-] e_[Mg/Fe] Error associated to magnesium
61- 64 F4.1 Gyr Age ?=0 Stellar age (2)
66- 68 F3.1 Gyr e_Age ?=0 Error associated to stellar age (2)
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Note (1): it can be regarded as [Fe/H] for comparison with models
Note (2): stars without age available have a value of 0 in the Table
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Acknowledgements:
Marco Palla, marco.palla(at)inaf.it
Pablo Santos-Peral, Pablo.Santos-del-Peral(at)oca.eu
References:
Santos-Peral et al., 2020A&A...639A.140S 2020A&A...639A.140S, The AMBRE Project:
Spectrum normalisation influence on Mg abundances in the metal-rich
Galactic disc
Santos-Peral et al., 2021A&A...653A..85S 2021A&A...653A..85S, The AMBRE Project:
Solar neighbourhood chemodynamical constraints on Galactic disc evolution
(End) Marco Palla [UGent, Belgium], Patricia Vannier [CDS] 19-May-2022