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J/A+A/293/347 LMC F supergiants (Hill+, 1995)
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Chemical evolution of the Magellanic Clouds. VI. Chemical composition of nine F
supergiants from different regions of the Large Magellanic Cloud
Hill V., Andrievsky S., Spite M.
<Astron. Astrophys. 293, 347 (1995)>
=1995A&A...293..347H (SIMBAD/NED Reference)
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ADC_Keywords: Magellanic Clouds; Stars, supergiant; Spectroscopy; Abundances
Keywords: stars: abundances - stars: supergiants - Magellanic Clouds -
galaxies: abundances
Abstract:
In an effort to increase the available information on the chemical content
of the Magellanic Clouds, we investigated nine F supergiants from the field
of the LMC by high-resolution spectroscopy, in order to obtain the elemental
abundance ratios for C, O, {alpha}-elements, Fe peak and heavy elements.
The stars are widely distributed over the LMC. An LTE analysis has given
the following results: 1. All investigated stars are metal deficient
([Fe/H] value covers the interval from -0.34dex to -0.14dex; mean value:
-0.27dex). 2. The iron abundance appears to be surprisingly uniform,
although the stars were chosen in different regions of the LMC. The star-to
star scatter is within the observation uncertainty. 3. For all
stars[C/Fe]<~0 but still exceeds the value observed in LMC HII regions by
+0.2dex. 4. The [O/Fe] ratio is very similar to the one found for the
Galactic supergiant Canopus, and the star-to-star scatter is small
({sigma}=0.1dex) 5. Sodium does not seem to be enhanced (in average) in
the LMC supergiants. 6. Among {alpha}-elements Si, S, Ca and Ti are
enhanced in LMC supergiants, but Mg is slightly underabundant (with respect
to Fe) when compared with solar value. 7. Heavy s- and r- process elements
are overabundant by +0.3dex in average. This overabundance could be
somewhat smaller for Eu, a pure r- process element.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
appendix 186 260 Lines used in the analysis, with their
equivalent width and individual abundance for
each of the nine investigated LMC supergiants
and for Canopus.
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Byte-by-byte Description of file: appendix
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Bytes Format Units Label Explanations
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2- 8 F7.2 0.1nm Lambda Central wavelength of the line
11- 12 A2 --- El. Name of the element
13 I1 --- El.Ion. Degree of ionization of the element
(1 for neutral and 2 for ionized species)
15- 19 F5.2 eV Xi(ex) Excitation potential of the line
22- 26 F5.2 --- log(gf) Line transition probability in log scale
30- 34 F5.1 0.1nm WG244 []? Equivalent width of the line for star G244
35 A1 --- n_AG244 [* ] Note on the abundance determination (1)
38- 42 F5.2 Sun AG244 []? Abundance normalised to the Sun for G244
46- 50 F5.1 0.1nm WG258 []? Equivalent Width of the line for star G258
51 A1 --- n_AG258 [* ] Note on the abundance determination (1)
54- 58 F5.2 Sun AG258 []? Abundance normalised to the Sun for G258
62- 66 F5.1 0.1nm WG274 []? Equivalent Width of the line for star G274
67 A1 --- n_AG274 [* ] Note on the abundance determination (1)
70- 74 F5.2 Sun AG274 []? Abundance normalised to the Sun for G274
78- 82 F5.1 0.1nm WG319 []? Equivalent Width of the line for star G319
83 A1 --- n_AG319 [* ] Note on the abundance determination (1)
86- 90 F5.2 Sun AG319 []? Abundance normalised to the Sun for G319
94- 98 F5.1 0.1nm WG396 []? Equivalent Width of the line for star G396
99 A1 --- n_AG396 [* ] Note on the abundance determination (1)
102-106 F5.2 Sun AG396 []? Abundance normalised to the Sun for G396
110-114 F5.1 0.1nm WG406 []? Equivalent Width of the line for star G406
115 A1 --- n_AG406 [* ] Note on the abundance determination (1)
118-122 F5.2 Sun AG406 []? Abundance normalised to the Sun for G406
126-130 F5.1 0.1nm WG439 []? Equivalent Width of the line for star G439
131 A1 --- n_AG439 [* ] Note on the abundance determination (1)
134-138 F5.2 Sun AG439 []? Abundance normalised to the Sun for G439
142-146 F5.1 0.1nm WG501 []? Equivalent Width of the line for star G501
147 A1 --- n_AG501 [* ] Note on the abundance determination (1)
150-154 F5.2 Sun AG501 []? Abundance normalised to the Sun for G501
158-162 F5.1 0.1nm WG538 []? Equivalent Width of the line for star G538
163 A1 --- n_AG538 [* ] Note on the abundance determination (1)
166-170 F5.2 Sun AG538 []? Abundance normalised to the Sun for G538
174-178 F5.1 0.1nm WCan []? Equivalent Width of the line for Canopus
(taken from Luck & Lambert, 1985 and
Desikachary & Hearnshaw, 1982)
179 A1 --- n_ACan [*# ] Note on the abundance determination (1)
182-186 F5.2 Sun ACan []? Abundance normalised to the Sun for Canopus
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Note (1): An asterisk following the equivalent width means that the
corresponding abundance was determined by fitting the the
line profile rather than using this equivalent width, due
to a severe blend or to the hyperfine structure of the line.
"#" means that the sulfur abundance for Canopus was taken from
Spite et al. (1989c)
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Positions of the stars (Fehrenbach & Duflot, 1970, 1973)
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Star CPD HD/HDE RA DE
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G244 67 405 269187 05 14.08 -67 19.2
G258 269355 05 19.05 -69 48.8
G274 05 22.32 -66 57.6
G319 05 28.84 -66 03.8
G396 05 35.53 -66 47.2
G406 269868 05 36.69 -67 42.3
G439 270025 05 42.40 -68 28.8
G501 04 56.85 -67 09.7
G538 271018 05 07.11 -66 21.9
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References:
Desikachary K. & Hearnshaw J.B., 1982, MNRAS 201, 707
Fehrenbach C. & Duflot M., 1970 Astron. Astrophys. Special Suppl. 1.
Fehrenbach C. & Duflot M., 1973 Astron. Astrophys. Suppl. 10, 231
Luck R.E. & Lambert D.L., 1985, ApJ 298, 782
Spite M. & Spite F., 1989, A&A 234, 67
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(End) Patricia Bauer [CDS] 26-Jul-1994