J/A+A/581/A70 Grid of NLTE EW and NLTE corrections BaII lines (Korotin+, 2015)
Grid of theoretical NLTE equivalent widths of four Ba II lines and barium
abundance in cool stars.
Korotin S.A., Andrievsky S.M., Hansen C.J., Caffau E., Bonifacio P.,
Spite M., Spite F., Francois P.
<Astron. Astrophys. 581, A70 (2015)>
=2015A&A...581A..70K 2015A&A...581A..70K
ADC_Keywords: Stars, late-type ; Abundances ; Line Profiles
Keywords: line: profiles - stars: abundances - stars: late-type
Abstract:
We present a grid of computed non-local thermodynamic equilibrium
(NLTE) equivalent widths (EW) and NLTE abundance corrections for four
Ba II lines: 4554, 5853, 6141, and 6496Å. The grid can be useful in
deriving the NLTE barium abundance in stars having parameters in the
following ranges: effective temperature from 4000K to 6500K, surface
gravity log g from 0 to 5, microturbulent velocity 0km/s to 3km/s,
metallicity [Fe/H] from -2 to +0.5, and [Ba/Fe] from -0.4 to +0.6. The
NLTE abundance can be either derived by EW interpolation (using the
observed Ba II line EW) or by using the NLTE correction applied to a
previously determined LTE abundance. Ba II line equivalent widths and
the NLTE corrections were calculated using the updated MULTI code and
the Ba II atomic model that was previously applied to determine the
NLTE barium abundance in different types of stars. The grid is
available on-line through the web, and we find that the grid Ba NLTE
corrections are almost as accurate as direct NLTE profile fitting (to
within 0.05-0.08dex). For the weakest Ba II line (5853Å) the LTE
abundances almost agree with the NLTE abundances, whereas the other
three Ba II lines, 4554, 6141, and 6496Å, need NLTE corrections even
at the highest metallicities tested here. The 4554Å line is extremely
strong and should not be used for abundance analysis above [Fe/H]=-1.
Furthermore, we tested the impact of different model atmospheres and
spectrum synthesis codes and found average differences of 0.06 dex and
0.09 dex, respectively, for all four lines. At these metallicities we
find an average Delta NLTE of ±0.1dex for the three useful Ba lines
for subsolar cool dwarfs.
Description:
The following stellar parameter ranges are covered by our grid, which
focuses on more metal-rich stars (compared to the very metal-poor and
extremely metal-poor stas) that are typically targeted in current and
future surveys:
- effective temperature: 4000-6500K, step = 250K;
- surface gravity: 0-5, step = 0.5
- microturbulent velocity: 0-3km/s, step = 1km/s;
- metallicity: [Fe/H] = +0.5, 0.0, -0.5, -1.0, -1.5 and -2.0;
- relative barium abundance: [Ba/Fe] = -0.40, -0.20, 0.00, +0.20,
+0.40, +0.60.
For the models with [Fe/H] below -1.00 we calculated NLTE equivalent
widths with an increased atmosphere abundance of alpha-elements
([alpha/Fe]=+0.4), while for a metallicity of -0.5 both cases (solar
alpha-element abundance and an increased one) were considered.
The NLTE equivalent widths of the four barium lines were calculated:
4554, 5853, 6141, and 6496Å.
Tables 4 and 5 contain the NLTE equivalent widths and NLTE
corrections, respectively. For each barium line we selected six values
of [Ba/Fe] (-0.4, -0.2, 0.0, +0.2, +0.4 and +0.6) for the NLTE EW
grid, and three values of [Ba/Fe] (-0.2, 0.1, and +0.4) for the NLTE
correction grid. For each of these values we list in the corresponding
table the EWs or corrections calculated for the full set of effective
temperature, surface gravity, microturbulent velocity, and
metallicity.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 166 3332 Equivalent widths for BaII lines
table5.dat 106 3332 NLTE corrections for BaII lines
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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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2- 6 F5.0 K Teff [4000/6500] Effective temperature
7- 11 F5.1 [cm/s2] logg [0/5] Surface gravity
12- 15 F4.0 km/s Vt [0/3] Microturbulent velocity
16- 21 F6.1 [Sun] [Fe/H] [-2/0.5] Metallicity
22 A1 --- a [a] Flag for increased atmosphere abundance
of α-elements by +0.4
23- 28 F6.0 0.1pm W1-0.4 EW line 4554 for [Ba/Fe]=-0.4 (mÅ)
29- 34 F6.0 0.1pm W1-0.2 EW line 4554 for [Ba/Fe]=-0.2 (mÅ)
35- 40 F6.0 0.1pm W1+0.0 EW line 4554 for [Ba/Fe]= 0.0 (mÅ)
41- 46 F6.0 0.1pm W1+0.2 EW line 4554 for [Ba/Fe]=+0.2 (mÅ)
47- 52 F6.0 0.1pm W1+0.4 EW line 4554 for [Ba/Fe]=+0.4 (mÅ)
53- 58 F6.0 0.1pm W1+0.6 EW line 4554 for [Ba/Fe]=+0.6 (mÅ)
59- 64 F6.0 0.1pm W2-0.4 EW line 5853 for [Ba/Fe]=-0.4 (mÅ)
65- 70 F6.0 0.1pm W2-0.2 EW line 5853 for [Ba/Fe]=-0.2 (mÅ)
71- 76 F6.0 0.1pm W2+0.0 EW line 5853 for [Ba/Fe]= 0.0 (mÅ)
77- 82 F6.0 0.1pm W2+0.2 EW line 5853 for [Ba/Fe]=+0.2 (mÅ)
83- 88 F6.0 0.1pm W2+0.4 EW line 5853 for [Ba/Fe]=+0.4 (mÅ)
89- 94 F6.0 0.1pm W2+0.6 EW line 5853 for [Ba/Fe]=+0.6 (mÅ)
95-100 F6.0 0.1pm W3-0.4 EW line 6141 for [Ba/Fe]=-0.4 (mÅ)
101-106 F6.0 0.1pm W3-0.2 EW line 6141 for [Ba/Fe]=-0.2 (mÅ)
107-112 F6.0 0.1pm W3+0.0 EW line 6141 for [Ba/Fe]= 0.0 (mÅ)
113-118 F6.0 0.1pm W3+0.2 EW line 6141 for [Ba/Fe]=+0.2 (mÅ)
119-124 F6.0 0.1pm W3+0.4 EW line 6141 for [Ba/Fe]=+0.4 (mÅ)
125-130 F6.0 0.1pm W3+0.6 EW line 6141 for [Ba/Fe]=+0.6 (mÅ)
131-136 F6.0 0.1pm W4-0.4 EW line 6496 for [Ba/Fe]=-0.4 (mÅ)
137-142 F6.0 0.1pm W4-0.2 EW line 6496 for [Ba/Fe]=-0.2 (mÅ)
143-148 F6.0 0.1pm W4+0.0 EW line 6496 for [Ba/Fe]= 0.0 (mÅ)
149-154 F6.0 0.1pm W4+0.2 EW line 6496 for [Ba/Fe]=+0.2 (mÅ)
155-160 F6.0 0.1pm W4+0.4 EW line 6496 for [Ba/Fe]=+0.4 (mÅ)
161-166 F6.0 0.1pm W4+0.6 EW line 6496 for [Ba/Fe]=+0.6 (mÅ)
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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2- 6 F5.0 K Teff [4000/6500] Effective temperature
7- 11 F5.1 [cm/s2] logg [0/5] Surface gravity
12- 15 F4.0 km/s Vt [0/3] Microturbulent velocity
16- 21 F6.1 [Sun] [Fe/H] [-2/0.5] Metallicity
22 A1 --- a [a] Flag for increased atmosphere abundance
of α-elements +0.4
23- 29 F7.2 0.1pm d1-0.2 NLTE correction of 4554 line for [Ba/Fe]=-0.2
30- 36 F7.2 0.1pm d1+0.1 NLTE correction of 4554 line for [Ba/Fe]=+0.1
37- 43 F7.2 0.1pm d1+0.4 NLTE correction of 4554 line for [Ba/Fe]=+0.4
44- 50 F7.2 0.1pm d2-0.2 NLTE correction of 5853 line for [Ba/Fe]=-0.2
51- 57 F7.2 0.1pm d2+0.1 NLTE correction of 5853 line for [Ba/Fe]=+0.1
58- 64 F7.2 0.1pm d2+0.4 NLTE correction of 5853 line for [Ba/Fe]=+0.4
65- 71 F7.2 0.1pm d3-0.2 NLTE correction of 6141 line for [Ba/Fe]=-0.2
72- 78 F7.2 0.1pm d3+0.1 NLTE correction of 6141 line for [Ba/Fe]=+0.1
79- 85 F7.2 0.1pm d3+0.4 NLTE correction of 6141 line for [Ba/Fe]=+0.4
86- 92 F7.2 0.1pm d4-0.2 NLTE correction of 6496 line for [Ba/Fe]=-0.2
93- 99 F7.2 0.1pm d4+0.1 NLTE correction of 6496 line for [Ba/Fe]=+0.1
100-106 F7.2 0.1pm d4+0.4 NLTE correction of 6496 line for [Ba/Fe]=+0.4
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Acknowledgements:
S.A. Korotin, serkor(at)skyline.od.ua
Astronomical Observatory of Odessa National University, Ukraine
(End) S.A. Korotin [Ast. obs Odessa Nat. Univ.], P. Vannier [CDS] 29-Jul-2015