J/MNRAS/370/2091 Abundances of HD 134439/40 and HD 211998 (Chen+, 2006)
The puzzling abundance pattern of HD 134439 and HD 134440.
Chen Y.Q., Zhao G.
<Mon. Not. R. Astron. Soc., 370, 2091-2096 (2006)>
=2006MNRAS.370.2091C 2006MNRAS.370.2091C
ADC_Keywords: Stars, late-type ; Abundances, peculiar
Keywords: stars: abundances _ stars: individual: HD 134439 -
stars: individual: HD 134440 - stars: late-type -
stars: Population II - Galaxy: evolution
Abstract:
Abundances of 18 elements are determined for the common proper-motion
pair, HD 134439 and HD 134440, which shows high [Mn/Fe] and low
[alpha/Fe] ratios as compared to normal halo stars. Moreover, puzzling
abundances are indicated from elements whose origins are normally
considered to be from the same nucleosynthesis history. Particularly,
we have found that [Mg/Fe] and [Si/Fe] are lower than [Ca/Fe] and
[Ti/Fe] by 0.1-0.3dex. When elemental abundances are interpreted in
term of their condensation temperatures (TC), obvious trends of
[X/Fe] versus TC for alpha elements and probably iron-peak elements as
well are shown. The hypothesis that these stars have formed from a
dusty environment in dwarf spheroidal (dSph) galaxy provides a
solution to the puzzling abundance pattern.
Description:
High-resolution UVES spectra were retrieved from the ESO archive
(http://www.eso.org) with the resolving power of 40000 and the
signal-to-noise ratio of 200 for HD 134439/40 and R∼60000 and
signal-to-noise ratio ∼400 for HD 211998. Subaru archive data
(http://smoka.nao.ac.jp) supplied additional HDS spectra for HD 134439
with R∼90000 and signal-to-noise ratio ∼300.
Objects:
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RA (2000) DE Designation(s) (Column)
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15 10 13.1 -16 22 46 HD 134439 = HIP 74235 (EW1)
15 10 13.0 -16 27 47 HD 134440 = HIP 74234 (EW2)
22 24 36.9 -72 15 19 HD 211998 = HIP 110618 (EW3)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 49 330 The atomic data and equivalent widths for
HD 134439 (1), HD 134440 (2) and HD 211998 (3)
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Ion Element and ionization level
6- 13 F8.3 0.1nm Lambda Wavelength
17- 20 F4.2 eV EP Excitation potential
24- 28 F5.2 --- loggf ?=- Oscillator strength
31- 35 F5.1 0.1pm EW1 ?=- Equivalent widths for HD134439
38- 42 F5.1 0.1pm EW2 ?=- Equivalent widths for HD134440
45- 49 F5.1 0.1pm EW3 ?=- Equivalent widths for HD211998
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 14-Nov-2006