J/MNRAS/444/3301 Oxygen abundance in Galactic disc Cepheids (Korotin+, 2014)
Oxygen abundance distribution in the Galactic disc.
Korotin S.A., Andrievsky S.M., Luck R.E., Lepine J.R.D., Maciel W.J.,
Kovtyukh V.V.
<Mon. Not. R. Astron. Soc., 444, 3301-3307 (2014)>
=2014MNRAS.444.3301K 2014MNRAS.444.3301K
ADC_Keywords: Stars, variable ; Abundances ; Milky Way
Keywords: stars: abundances - stars: variables: Cepheids - Galaxy: abundances -
Galaxy: disc - Galaxy: evolution
Abstract:
We performed a non-local thermodynamic equilibrium (NLTE) analysis of
the infrared oxygen triplet for a large number of Cepheid spectra
obtained with the Hobby-Eberly Telescope. These data were combined
with our previous NLTE results for stars observed with the Max Planck
Gesellschaft Telescope with the aim of investigating the oxygen
abundance distribution in the Galactic thin disc. We found the slope
of the radial (O/H) distribution to be equal -0.058dex/kpc. However,
we found some evidence that the distribution might become flatter in
the outer parts of the disc. This is supported by the results of other
authors who have studied open clusters, planetary nebulae and Hii
regions. Some mechanisms of flattening are discussed.
Description:
Our sample consists of two subsamples. One contains the Hobby-Eberly
Telescope (HET) data, described in detail by Luck & Lambert
(2011AJ....142..136L 2011AJ....142..136L, Cat. J/AJ/142/136). The second comprises the Max
Planck Gesellschaft (MPG) Telescope data, which are described in Luck
et al. (2013AJ....146...18L 2013AJ....146...18L). The observational data for both samples
were collected by one of the authors (R.E. Luck).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 48 271 Parameters and abundances for program Cepheids
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See also:
J/AJ/142/136 : Spectroscopy of Cepheids. l=30-250° (Luck+, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Cepheid name
11 A1 --- m_Name [AB] Multiplicity index on Name
13- 17 F5.3 --- Phase [0/1]? Phase
19- 22 I4 K Teff [5000/6666] Effective temperature
24- 27 F4.2 [cm/s2] logg [0.8/3] Surface gravity
29- 32 F4.2 km/s Vt [2.9/8.7] Microturbulent velocity
34- 37 F4.2 [-] (Fe/H) [6.9/8] Iron abundance
39- 42 F4.2 [-] (O/H) [8.2/9.1] Oxygen abundance
44- 48 F5.2 kpc RG [5/17.2] Galactocentric distance
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 29-Apr-2015