J/A+A/627/A177 Non-LTE analysis of K I in late-type stars (Reggiani+, 2019)
Non-LTE analysis of K I in late-type stars.
Reggiani H., Amarsi A.M., Lind K., Barklem P.S., Zatsarinny O.,
Bartschat K., Fursa D.V., Bray I., Spina L., Melendez J.
<Astron. Astrophys. 627, A177 (2019)>
=2019A&A...627A.177R 2019A&A...627A.177R (SIMBAD/NED BibCode)
ADC_Keywords: Stars, late-type ; Abundances
Keywords: stars: abundances - stars: late-type - line: formation -
Galaxy: evolution - Galaxy: abundances
Abstract:
Older models of Galactic chemical evolution (GCE) predict [K/Fe]
ratios as much as 1dex lower than those inferred from stellar
observations. Abundances of potassium are mainly based on analyses of
the 7698Å resonance line, and the discrepancy between GCE models
and observations is in part caused by the assumption of local
thermodynamic equilibrium (LTE) in spectroscopic analyses.
We study the statistical equilibrium of KI, focusing on the non-LTE
effects on the 7698Å line. We aim to determine how non-LTE
abundances of potassium can improve the analysis of its chemical
evolution, and help to constrain the yields of GCE models.
We construct a new model KI atom that employs the most up-to-date
atomic data. In particular, we calculate and present inelastic e+K
collisional excitation cross-sections from the convergent
close-coupling (CCC) and the B-Spline R-matrix (BSR) methods, and H+K
collisions from the two-electron model (LCAO). We constructed a fine,
extended grid of non-LTE abundance corrections based on 1D MARCS
models that span 4000<Teff/=K<8000, 0.50<logg<5.00, -5.00<[Fe/H]<+0.50,
and applied the corrections to potassium abundances extracted from the
literature.
Description:
We built a new model atom of potassium in order to test the non-LTE
effects in stellar abundances estimations. We used state-of-the-art
calculations of neutral hydrogen and electronic collisional
cross-sections and photoionization cross-sections.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
abund.dat 43 106 LTE and NLTE stellar abundances (Table A1)
nltegrid.dat 55 83442 NLTE correction grid (update, 16-Apr-2021)
states.dat 20 15 K states
bsrra.dat 22 6975 e+K excitation BSR rate coefficients
cccra.dat 22 6975 e+K excitation CCC rate coefficients
bsriora.dat 19 465 e+K ionization BSR rate coefficients
ccciora.dat 19 465 e+K ionization CCC rate coefficients
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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- 12 A12 --- Star Star name
14- 17 I4 K Teff Effective temperature
19- 22 F4.2 [cm/s2] logg Surface Gravity
24- 28 F5.2 [-] [Fe/H] Metallicity
30- 33 F4.2 km/s vt Microturbulence velocity
35- 38 F4.2 --- AKnlte Non-LTE potassium abundance A(K)
40- 43 F4.2 --- AKlte LTE potassium abundance A(K)
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Byte-by-byte Description of file: nltegrid.dat
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Bytes Format Units Label Explanations
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1- 4 I4 K Teff Effective temperature
6- 9 F4.2 [cm/s2] logg Surface Gravity
11- 15 F5.2 [-] [Fe/H] Metallicity
17 I1 km/s vt Microturbulence velocity
19- 23 F5.2 --- AKlte LTE potassium abundance A(K)
25- 30 I6 --- line Line
32- 39 F8.3 0.1nm EWnlte Non-LTE equivalent width
41- 48 F8.3 0.1nm EWlte LTE equivalent width
50- 55 F6.3 --- corr Correction
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Byte-by-byte Description of file: states.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Index State index
7- 8 A2 --- State State
13- 14 I2 --- g Statistical weight
16- 20 F5.3 eV Energy Excitation energy
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Byte-by-byte Description of file: bsrra.dat cccra.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- i1 Index of the initial state
4- 5 I2 --- i2 Index of the final state
7- 12 I6 K T Temperature
14- 22 A9 --- q Rate coefficient
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Byte-by-byte Description of file: bsriora.dat ccciora.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- i1 Index of the initial state
4- 9 I6 K T Temperature
11- 19 A9 --- q Rate coefficient
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Acknowledgements:
Henrique M. Reggiani, hreggiani(at)gmail.com
History:
22-Jul-2019: on-line version
16-Apr-2021: update nltegrid.dat file
(End) Patricia Vannier CDS 12-Jul-2019