J/A+A/687/A164 Red giants abundances and asteroseismic ages (Vitali+, 2024)
Exploring the dependence of chemical traits on metallicity.
Chemical trends for red giant stars with asteroseismic ages.
Vitali S., Slumstrup D., Jofre P., Casamiquela L., Korhonen H.,
Blanco-Cuaresma S., Winther M.L., Aguirre Bosen-Koch V.
<Astron. Astrophys. 687, A164 (2024)>
=2024A&A...687A.164V 2024A&A...687A.164V (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, giant ; Spectroscopy ; Abundances ; Stars, ages
Keywords: Galaxy: abundances - Galaxy: disk - stars: abundances -
techniques: spectroscopic
Abstract:
Given the massive spectroscopic surveys and the Gaia mission, the
Milky Way has turned into a unique laboratory to be explored using
abundance ratios that show a strong dependency with time. Within this
framework, the data provided through asteroseismology serve as a
valuable complement. Yet, it has been demonstrated that chemical
traits can not be used as universal relations across the Galaxy.
The aim of this work is to investigate the dependence on metallicity
of the chemical ratios employed for inferring stellar ages. We aim to
explore different combinations of neutron-capture, odd-Z and alpha
elements as a function of age, particularly focusing on their
metallicity dependence for a sample of 74 giant field stars.
Using UVES observations, we derive atmospheric parameters and
high-precision line-by-line chemical abundances (<0.04dex) for the
entire set of spectra, which covers a wide spread in age (up to 14Gyr)
and metallicity (-0.7<[Fe/H]<+0.1). Stellar ages are inferred from
astereoseismic information.
By fitting chemical-age trends for three different metallicity groups,
we estimated their dependence on metallicity. Simultaneously, we
identified those exhibiting stronger correlations with time. We found
that the stronger chemical-age relations ([Zr/alpha]) Are not
necessarily the ratios with the smaller dependence on metallicity
([Ce/alpha] and [Ce/Eu]).
We confirm the [n-capture/alpha]-age trends for evolved stars, wherein
the most significant correlation is evident in stars with
solar-metallicity, gradually diminishing in stars with lower iron
content. The lack of homogeneity within the metallicity range
highlights the intricate nature of our Galaxy's star formation
history and yield production. The dependence on metallicity of the
yields involving s-process elements and the influence of radial
stellar migration pose challenges to relying solely on chemical
abundances for dating stars. These findings contest the feasibility of
establishing universally applicable chemical clocks valid across the
entire Galaxy and across various metallicity ranges.
Description:
abund.dat: results of the spectroscopic analysis for each star stellar
parameters, mean abundances and the corresponding uncertainties.
Results for the ages computed with the BASTA pipeline.
lines.dat: Line used for the spectral analysis. We report the log(gf)
and the excitation potential values adopted for each line.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
lines.dat 28 192 Line used for the spectral analysis
abund.dat 522 71 Results of the spectroscopic analysis for each
star stellar parameters, mean abundances and
the corresponding uncertainties
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: lines.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 nm lambda Central wavelength
11- 14 A4 --- El Element symbol (e.g. Fe 1)
16- 21 F6.3 --- loggf Adopted log(gf) value
23- 28 F6.3 --- EP Excitation potential
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Byte-by-byte Description of file: abund.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- --- [Gaia DR3]
10- 28 I19 --- GaiaDR3 Gaia DR3 identifier
30- 46 A17 --- 2MASS 2MASS identifier (JHHMMSSss+DDMMSSs)
48- 54 F7.2 K Teff Surface temperature
56- 60 F5.2 K e_Teff Surface temperature uncertainty
62- 65 F4.2 [cm/s] loggspec Surface gravity from spectroscopy
67- 70 F4.2 [cm/s] e_loggspec Surface gravity uncertainty
72- 82 F11.9 [cm/s] loggseismic Surface gravity from seismic relation
84- 93 E10.4 [cm/s] e_loggseismic Surface gravity uncertainty
95- 98 F4.2 km/s vmic Microturbolence velocity
100-103 F4.2 km/s e_vmic Microturbolence velocity uncertainty
105-109 F5.2 --- [Fe/H] Mean abundance [Fe/H]
111-121 F11.9 --- e_[Fe/H] rms uncertainty on abundance [Fe/H]
123-127 F5.2 --- [Mg/H] Mean abundance [Mg/H]
129-139 F11.9 --- e_[Mg/H] rms uncertainty on abundance [Mg/H]
141-145 F5.2 --- [Si/H] Mean abundance [Si/H]
147-157 F11.9 --- e_[Si/H] rms uncertainty on abundance [Si/H]
159-163 F5.2 --- [Ti/H] Mean abundance [Ti/H]
165-175 F11.9 --- e_[Ti/H] rms uncertainty on abundance [Ti/H]
177-181 F5.2 --- [Y/H] Mean abundance [Y/H]
183-193 F11.9 --- e_[Y/H] rms uncertainty on abundance [Y/H]
195-199 F5.2 --- [Al/H] ? Mean abundance [Al/H]
201-211 F11.9 --- e_[Al/H] ? rms uncertainty on abundance [Al/H]
213-217 F5.2 --- [Sr/H] Mean abundance [Sr/H]
219-229 F11.9 --- e_[Sr/H] rms uncertainty on abundance [Sr/H]
231-235 F5.2 --- [Ca/H] Mean abundance [Ca/H]
237-247 F11.9 --- e_[Ca/H] rms uncertainty on abundance [Ca/H]
249-253 F5.2 --- [Zr/H] Mean abundance [Zr/H]
255-265 F11.9 --- e_[Zr/H] rms uncertainty on abundance [Zr/H]
267-271 F5.2 --- [Zn/H] Mean abundance [Zn/H]
273-283 F11.9 --- e_[Zn/H] rms uncertainty on abundance [Zn/H]
285-289 F5.2 --- [La/H] Mean abundance [La/H]
291-301 F11.9 --- e_[La/H] rms uncertainty on abundance [La/H]
303-307 F5.2 --- [Ce/H] Mean abundance [Ce/H]
309-319 F11.9 --- e_[Ce/H] rms uncertainty on abundance [Ce/H]
321-325 F5.2 --- [Nd/H] Mean abundance [Nd/H]
327-337 F11.9 --- e_[Nd/H] rms uncertainty on abundance [Nd/H]
339-343 F5.2 --- [V/H] Mean abundance [V/H]
345-355 F11.9 --- e_[V/H] rms uncertainty on abundance [V/H]
357-361 F5.2 --- [Eu/H] Mean abundance [Eu/H]
363-373 F11.9 --- e_[Eu/H] rms uncertainty on abundance [Eu/H]
375-379 F5.2 --- [Na/H] Mean abundance [Na/H]
381-391 F11.9 --- e_[Na/H] rms uncertainty on abundance [Na/H]
393-397 F5.2 --- [Sc/H] Mean abundance [Sc/H]
399-409 F11.9 --- e_[Sc/H] rms uncertainty on abundance [Sc/H]
411-415 F5.2 --- [Cr/H] Mean abundance [Cr/H]
417-427 F11.9 --- e_[Cr/H] rms uncertainty on abundance [Cr/H]
429-433 F5.2 --- [Mn/H] Mean abundance [Mn/H]
435-445 F11.9 --- e_[Mn/H] rms uncertainty on abundance [Mn/H]
447-451 F5.2 --- [Co/H] Mean abundance [Co/H]
453-463 F11.9 --- e_[Co/H] rms uncertainty on abundance [Co/H]
465-469 F5.2 --- [Ni/H] Mean abundance [Ni/H]
471-481 F11.9 --- e_[Ni/H] rms uncertainty on abundance [Ni/H]
483-487 F5.2 --- [Cu/H] Mean abundance [Cu/H]
489-499 F11.9 --- e_[Cu/H] rms uncertainty on abundance [Cu/H]
501-505 I5 Myr AgeBASTAmyr BASTA ages in Myr
507-511 F5.2 Gyr AgeBASTAgyr BASTA ages in Gyr
513-516 I4 Myr e_AgeBASTAmyr BASTA ages uncertainty in Myr
518-522 F5.3 Gyr e_AgeBASTAgyr BASTA ages uncertainty in Gyr
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Acknowledgements:
Sara Vitali, sara.vitali(at)mail.udp.cl
(End) Patricia Vannier [CDS] 02-Apr-2024