J/A+A/543/A160 Normalized spectra of 82 Kepler red giants (Thygesen+, 2012)
Atmospheric parameters of 82 red giants in the Kepler field.
Thygesen A.O., Frandsen, S., Bruntt H., Kallinger T., Andersen M.F.,
Elsworth Y.E., Hekker S., Karoff C., Stello D., Brogaard K., Burke C.,
Caldwell D.A., Christiansen J.L.
<Astron. Astrophys. 543, A160 (2012)>
=2012A&A...543A.160T 2012A&A...543A.160T
ADC_Keywords: Stars, giant ; Spectroscopy
Keywords: stars: abundances - stars: fundamental parameters -
methods: observational - techniques: spectroscopic
Abstract:
Accurate fundamental parameters of stars are essential for the
asteroseismic analysis of data from the NASA Kepler mission.
We aim at determining accurate atmospheric parameters and the
abundance pattern for a sample of 82 red giants that are targets for
the Kepler mission.
We have used high-resolution, high signal-to-noise spectra from three
different spectrographs. We used the iterative spectral synthesis
method VWA to derive the fundamental parameters from carefully
selected high-quality iron lines. After determination of the
fundamental parameters, abundances of 13 elements were measured using
equivalent widths of the spectral lines. Results: We identify
discrepancies in logg and [Fe/H], compared to the parameters based on
photometric indices in the Kepler Input Catalogue, Cat. V/133 (larger
than 2.0dex for logg and [Fe/H] for individual stars). The Teff found
from spectroscopy and photometry shows good agreement within the
uncertainties. We find good agreement between the spectroscopic logg
and the logg derived from asteroseismology. Also, we see indications
of a potential metallicity effect on the stellar oscillations.
We have determined the fundamental parameters and element abundances
of 82 red giants. The large discrepancies between the spectroscopic
logg and [Fe/H] and values in the Kepler Input Catalogue emphasize
the need for further detailed spectroscopic follow-up of the Kepler
targets in order to produce reliable results from the asteroseismic
analysis.
Description:
Normalized spectra of 82 red giants in the Kepler Field. Target names
are as found in the Kepler Input Catalogue (Kepler Mission Team 2009)
Also included spectra of 10 well-studied bright giants observed for
reference. 9 of the reference giants were chosen from the PASTEL
catalogue (Soubiran et al., 2010, Cat. B/pastel) and one, HD205512,
from the work of Luck & Heiter (2007AJ....133.2464L 2007AJ....133.2464L). All targets have
been shifted to laboratory wavelength using the radial velocities
quoted in the paper. Two columns are associated with each target file,
containing wavelength and flux.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 51 92 List of studied giants
sp/* . 92 Individual spectra
tablea1.dat 94 82 Fundamental atmospheric parameters for all red
giants in our sample
tablea2.dat 109 82 Elemental abundances for all targets where an
asteroseismic logg could be determined
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
B/pastel : The PASTEL catalogue (Soubiran+, 2010-)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Star name
14- 15 I2 h RAh Right ascension (J2000)
17- 18 I2 min RAm Right ascension (J2000)
20- 24 F5.2 s RAs Right ascension (J2000)
26 A1 --- DE- Declination sign (J2000)
27- 28 I2 deg DEd Declination (J2000)
30- 31 I2 arcmin DEm Declination (J2000)
33- 37 F5.2 arcsec DEs Declination (J2000)
39- 51 A13 --- FileName Name of the spectrum file in subdirectory sp
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Byte-by-byte Description of file: sp/*
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Bytes Format Units Label Explanations
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2- 11 F10.5 0.1nm lambda [3999/8850] Wavelength vector
14- 23 F10.8 --- nFlux Normalized flux
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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- 3 A3 --- --- [KIC]
5- 12 I8 --- KIC KIC (Cat. V/133) identification
14- 17 I4 K Teff1 Effective temperature with VWA (±80K) (1)
19- 22 F4.2 [cm/s2] logg1 Surface gravity with VWA (±0.2dex) (1)
24- 27 F4.2 km/s xi1 Microturbulent velocity with VWA (±0.15km/s) (1)
29- 33 F5.2 [Sun] [Fe/H]1 Metallicity from FeI and FeII (±0.15dex) (1)
35- 38 I4 K Teff2 ?=- Effective temperature with Kepler
asteroseismic analysis (±100K)
40- 43 F4.2 [cm/s2] logg2 ?=- Surface gravity with Kepler
asteroseismic analysis (±0.1dex)
45- 48 I4 K Teff3 ?=- Effective temperature with KIC (V/133)
50- 53 F4.2 [cm/s2] logg3 ?=- Surface gravity with KIC (V/133)
55- 59 F5.2 [Sun] [Fe/H]3 ?=- Metallicity with KIC (V/133)
61- 64 I4 K Teff ?=- VWA + Kepler effective temperature (2)
66- 70 F5.2 [Sun] [Fe/H] ?=- VWA + Kepler metallicity, FeII is used
as the measure of [Fe/H] (2)
72- 75 F4.2 km/s xi ?=- VWA + Kepler microturbulent velocity ξ (2)
77- 79 F3.1 km/s vsini Projected rotational velocity (±1.0km/s)
81- 83 F3.1 km/s vmacro Macroturbulent velocity (±1.0km/s)
85- 90 F6.1 km/s RV Radial velocity (±0.15km/s)
92- 94 A3 --- Type Giant type: RGB = red giant branch,
RC = red clump, SC = secondary clump
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Note (1): VWA software poackage (see Bruntt et al. 2004A&A...425..683B 2004A&A...425..683B,
2008A&A...478..487B 2008A&A...478..487B, 2010A&A...519A..51B 2010A&A...519A..51B), from spectroscopy.
Note (2): values are determined with VWA by fixing the gravity from the
asteroseismic Kepler value.
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [KIC]
5- 12 I8 --- KIC KIC (Cat. V/133) identification
13 A1 --- R [*] (KIC 9574235): abundances based on
the spectroscopic (VWA) logg
15- 19 F5.2 [Sun] [C/H] ?=- [C/H] abundance (±0.5dex)
21- 25 F5.2 [Sun] [O/H] ?=- [O/H] abundance (±0.5dex)
27- 31 F5.2 [Sun] [Si/H] ?=- [Si/H] abundance (±0.2dex)
33- 37 F5.2 [Sun] [Ca/H] ?=- [Ca/H] abundance (±0.2dex)
39- 43 F5.2 [Sun] [Sc/H] ?=- [Sc/H] abundance (±0.2dex)
45- 49 F5.2 [Sun] [TiI/H] ?=- [TiI/H] abundance (±0.2dex)
51- 55 F5.2 [Sun] [TiII/H] ?=- [TiII/H] abundance (±0.2dex)
57- 61 F5.2 [Sun] [V/H] ?=- [V/H] abundance (±0.2dex)
63- 67 F5.2 [Sun] [CrI/H] ?=- [CrI/H] abundance (±0.2dex)
69- 73 F5.2 [Sun] [CrII/H] ?=- [CrII/H] abundance (±0.2dex)
75- 79 F5.2 [Sun] [Mn/H] ?=- [Mn/H] abundance (±0.2dex)
81- 85 F5.2 [Sun] [FeI/H] ?=- [FeI/H] abundance (±0.15dex)
87- 91 F5.2 [Sun] [FeII/H] ?=- [FeII/H] abundance (±0.15dex)
93- 97 F5.2 [Sun] [Co/H] ?=- [Co/H] abundance (±0.2dex)
99-103 F5.2 [Sun] [Ni/H] ?=- [Ni/H] abundance (±0.2dex)
105-109 F5.2 [Sun] [Y/H] ?=- [Y/H] abundance (±0.2dex)
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History:
* 16-Jul-2012: on-line spectra
* 24-May-2013: tables A1 and A2 added
Acknowledgements:
Anders Thygesen, aot06(at)phys.au.dk
(End) A.O. Thygesen [ZAH, Heidelberg], Patricia Vannier [CDS] 25-May-2012