J/A+A/367/86 Chemical abundances of 5 Galactic disk B stars (Smartt+, 2001)
Chemical abundances in the inner 5 kpc of the Galactic disk
Smartt S.J., Venn K.A., Dufton P.L., Lennon D.J., Rolleston W.R.J.,
Keenan F.P.
<Astron. Astrophys. 367, 86 (2001)>
=2001A&A...367...86S 2001A&A...367...86S
ADC_Keywords: Stars, early-type ; Equivalent widths
Keywords: stars: early-type - stars: atmospheres - stars: abundances -
Galaxy: evolution - Galaxy: center - Galaxy: abundances
Abstract:
High-resolution, high signal-to-noise spectral data are presented for
four young B-type stars lying towards the Galactic Centre.
Determination of their atmospheric parameters from their absorption
line profiles, and uvby photometric measurement of the continua
indicate that they are massive objects lying slightly out of the
plane, and were probably born in the disk between 2.5-5kpc from the
Centre. We have carried out a detailed absolute and differential
line-by-line abundance analyses of the four stars compared to two
stars with very similar atmospheric parameters in the solar
neighbourhood. The stars appear to be rich in all the well sampled
chemical elements (C, N, Si, Mg, S, Al), except for oxygen. Oxygen
abundances derived in the atmospheres of these four stars are very
similar to that in the solar neighbourhood. If the photospheric
composition of these young stars is reflective of the gaseous ISM in
the inner Galaxy, then the values derived for the enhanced metals are
in excellent agreement with the extrapolation of the Galactic
abundance gradients previously derived by Rolleston et al.
(2000A&A...363..537R 2000A&A...363..537R) and others. However, the data for oxygen
suggests that the inner Galaxy may not be richer than normal in this
element, and the physical reasons for such a scenario are unclear.
Objects:
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RA (2000) DE Designation(s)
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18 50 07.0 -13 03 26 LS 5130
17 49 34.9 -38 59 45 LS 4419
18 13 58.6 -30 29 30 LS 4784
00 13 14.2 +15 11 01 gamma Peg
18 47 20.3 -18 15 42 LS 5127
17 39 27.9 +46 00 23 iota Her
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table9.dat 41 168 Equivalent widths of the non-diffuse helium lines
and the metal lines in the stars LS5130, LS4419,
LS4784 and the spectroscopic standard γ Peg
table10.dat 24 104 Equivalent widths of the non-diffuse helium lines
and the metal lines in the stars LS5127 and the
spectroscopic standard iota-Her
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See also:
J/A+A/275/101 : Chemical evolution of the galactic disk I. (Edvardsson+ 1993)
J/A+AS/102/603 : Chemical evolution of the galactic disk II. (Edvardsson+ 1993)
Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Ion Atomic specie
7- 13 F7.2 0.1nm line Laboratory wavelength of the transition
15- 17 I3 0.1pm EWLS5130 ? LS5130 equivalent width
18 A1 --- u_EWLS5130 [a-c] Flag for error on EWLS5130 (1)
20- 22 I3 0.1pm EWLS4419 ? LS4419 equivalent width
23 A1 --- u_EWLS4419 [a-c] Flag for error on EWLS4419 (1)
25- 26 I2 --- n_EWLS4419 ? Note on EWLS4419 (2)
29- 31 I3 0.1pm EWLS4784 ? LS4784 equivalent width
32 A1 --- u_EWLS4784 [a-c] Flag for error on EWLS4784 (1)
34- 35 I2 --- n_EWLS4784 ? Note on EWLS4784 (2)
38- 40 I3 0.1pm EWgamPeg ? gamma-Peg equivalent width
41 A1 --- u_EWgamPeg [a-c] Flag for error on EWgamPeg (1)
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Note (1): Error flag:
a: error less than 10%
b: error less than 20%
c: error greater than 20%.
Note (2): There are notes appended to some features:
1: Blend of OII 3982.72 and SIII 3983.77
2: Includes the OII, NII and CII lines at 4075-4076Å
3: Blended with ArII 4131.71
4: Blended with NII 4643.09
5: Blended with OII 4649.14/4650.84
6: Blended with OII 4705.35
7: Also includes CII 3920.69
8: Blended with OII 4277.40
9: Blended with CII 4374.27
10: Blended with NII 4530.40
11: Blended with NII 4621.29
12: Blended with SII 4815.52
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Byte-by-byte Description of file: table10.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Ion Atomic specie
7- 13 F7.2 0.1nm line Laboratory wavelength of the transition
15- 17 I3 0.1pm EWLS5127 ? LS5127 equivalent width
18 A1 --- u_EWLS5127 [a-c] Flag for error on EWLS5127 (1)
20- 22 I3 0.1pm EWiotaHer ? ι Her equivalent width
23 A1 --- u_EWiotaHer [a-c] Flag for error on EWiotaHer (1)
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Note (1): Error flag:
a: error less than 10%
b: error less than 20%
c: error greater than 20%.
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Acknowledgements: Stephen Smartt
(End) Patricia Bauer [CDS] 08-Feb-2001