J/A+A/688/A123 Line list and abundance errors (Xylakis-Dornbusch+, 2024)
The R-Process Alliance: Analysis of limited-r stars.
Xylakis-Dornbusch T., Hansen T.T., Beers T.C., Christlieb N., Ezzeddine R.,
Frebel A., Holmbeck E., Placco V.M., Roederer I.U., Sakari C.M., Sneden C.
<Astron. Astrophys. 688, A123 (2024)>
=2024A&A...688A.123X 2024A&A...688A.123X (SIMBAD/NED BibCode)
ADC_Keywords: Stars, peculiar ; Abundances ; Equivalent widths
Keywords: stars: abundances - stars: chemically peculiar -
stars: kinematics and dynamics - stars: Population II
Abstract:
In recent years, the R-Process Alliance (RPA) has conducted a
successful search for stars that are enhanced in elements produced by
the rapid neutron-capture (r-)process. In particular, the RPA has
uncovered a number of stars that are strongly enriched in light
r-process elements, such as Sr, Y, and Zr. These so-called limited-r
stars were investigated to explore the astrophysical production
site(s) of these elements.
We investigate the possible formation sites for light neutron-capture
elements by deriving detailed abundances for neutron-capture elements
from high-resolution spectra with a high signal-to-noise ratio of
three limited-r stars.
We conducted a kinematic analysis and a 1D local thermodynamic
equilibrium spectroscopic abundance analysis of three stars.
Furthermore, we calculated the lanthanide mass fraction (XLa) of our
stars and of limited-r stars from the literature.
We found that the abundance pattern of neutron-capture elements of
limited-r stars behaves differently depending on their [Ba/Eu] ratios,
and we suggest that this should be taken into account in future
investigations of their abundances. Furthermore, we found that the XLa
of limited-r stars is lower than that of the kilonova AT2017gfo. The
latter seems to be in the transition zone between limited-r XLa and
that of r-I and r-II stars. Finally, we found that unlike r-I and r-II
stars, the current sample of limited-r stars is largely born in the
Galaxy and is not accreted.
Description:
Uncertainties in the determination of abundances due to the
uncertainties in stellar parameters and information for the line list
that was used for the abundance analysis.
Objects:
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RA (2000) DE Designation(s)
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00 38 59.67 +27 25 51.6 2MASSJ00385967+2725516 = TIC 25696176
20 31 35.31 -31 27 31.9 2MASSJ20313531-3127319 = TIC 441296084
21 40 23.04 -12 27 03.5 2MASSJ21402305-1227035 = TIC 242073983
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 85 3 Stellar parameters of the target stars
table4.dat 71 1059 For each absorption line the wavelength,
excitation potential, loggf, EW, σEW,
logε, and respective references
refs.dat 176 33 References
tablea1.dat 53 99 The uncertainty in the abundance determination
due to {DELTA}Teff, {DELTA}logg, {DELTA}χ,
{DELTA}[M/H], and σ systematic
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [2MASS]
7- 23 A17 --- 2MASS Star 2MASS name (JHHMMSSss+DDMMSSs)
25- 26 I2 h RAh Right ascension (J2000)
28- 29 I2 min RAm Right ascension (J2000)
31- 34 F4.1 s RAs Right ascension (J2000)
36 A1 --- DE- Declination sign (J2000)
37- 38 I2 deg DEd Declination (J2000)
40- 41 I2 arcmin DEm Declination (J2000)
43- 46 F4.1 arcsec DEs Declination (J2000)
48- 51 I4 K Teff Effective temperature
53- 54 I2 K e_Teff Effective temperature error
56- 59 F4.2 [cm/s2] logg Surface gravity
61- 64 F4.2 [cm/s2] e_logg Surface gravity error
66- 70 F5.2 [-] [Fe/H] Metallicity
72- 75 F4.2 [-] e_[Fe/H] Metallicity error
77- 80 F4.2 km/s vmic Microturbulent velocity
82- 85 F4.2 km/s e_vmic Microturbulent velocity error
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS Star 2MASS name (JHHMMSSss+DDMMSSs)
19- 24 A6 --- Species Species
25- 31 F7.2 0.1nm lambda Wavelength
33- 36 F4.2 eV Xi ?=- Excitation potential
38- 42 F5.2 [-] loggf ?=- Atomic transition probability
44- 50 F7.3 0.1pm EW ? Equivalent width
51 A1 --- n_EW [s] s for synth
53- 59 F7.3 0.1pm e_EW ? Equivalent width uncertainty
60 A1 --- neEW [s] s for synth
61- 67 F7.3 [-] logeps Absolute abundance logε
70- 71 I2 --- Ref ?=- Reference, in refs.dat file
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 45 A22 --- Aut Author's name
47-176 A130 --- Com Comments
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS Star 2MASS name (JHHMMSSss+DDMMSSs)
19- 24 A6 --- Element Element
26- 30 F5.2 K DTeff Uncertainty in Teff
32- 36 F5.2 [cm/s2] Dlogg Uncertainty in logg
38- 42 F5.2 km/s Dchi Uncertainty in microturbulence velocity
44- 48 F5.2 [-] D[M/H] Uncertainty uncertainty in metallicity
50- 53 F4.2 [-] esys Systematic uncertainty
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Acknowledgements:
Theodora Xylakis-Dornbusch, txylaki(at)lsw.uni-heidelberg.de
(End) T. Xylakis-Dornbusch [LSW/ZAH, Heidelberg], P. Vannier [CDS] 02-Aug-2024