J/MNRAS/450/2764 Spectroscopic survey of Kepler stars. I. (Niemczura+, 2015)
Spectroscopic survey of Kepler stars.
I. HERMES/Mercator observations of A- and F-type stars.
Niemczura E., Murphy S.J., Smalley B., Uytterhoeven K., Pigulski A.,
Lehmann H., Bowman D.M., Catanzaro G., Van Aarle E., Bloemen S.,
Briquet M., De Cat P., Drobek D., Eyer L., Gameiro J.F.S., Gorlova N.,
Kaminski K., Lampens P., Marcos-Arenal P., Papics P.I., Vandenbussche B.,
Van Winckel H., Steslicki M., Fagas M.
<Mon. Not. R. Astron. Soc., 450, 2764-2783 (2015)>
=2015MNRAS.450.2764N 2015MNRAS.450.2764N (SIMBAD/NED BibCode)
ADC_Keywords: Stars, peculiar ; Abundances
Keywords: stars: abundances - stars: chemically peculiar - stars: general -
stars: rotation
Abstract:
The Kepler space mission provided near-continuous and high-precision
photometry of about 207000 stars, which can be used for
asteroseismology. However, for successful seismic modeling it is
equally important to have accurate stellar physical parameters.
Therefore, supplementary ground-based data are needed. We report the
results of the analysis of high-resolution spectroscopic data of A-
and F-type stars from the Kepler field, which were obtained with the
HERMES spectrograph on the Mercator telescope. We determined spectral
types, atmospheric parameters and chemical abundances for a sample of
117 stars. Hydrogen Balmer, FeI, and FeII lines were used to derive
effective temperatures, surface gravities, and microturbulent
velocities. We determined chemical abundances and projected rotational
velocities using a spectrum synthesis technique. The atmospheric
parameters obtained were compared with those from the Kepler Input
Catalogue (KIC), confirming that the KIC effective temperatures are
underestimated for A stars. Effective temperatures calculated by
spectral energy distribution fitting are in good agreement with those
determined from the spectral line analysis. The analysed sample
comprises stars with approximately solar chemical abundances, as well
as chemically peculiar stars of the Am, Ap, and λ Boo types.
The distribution of the projected rotational velocity, vsini, is
typical for A and F stars and ranges from 8 to about 280km/s, with a
mean of 134km/s.
Description:
In this paper we analyse high-resolution spectra taken with the
cross-dispersed, fibre-fed echelle spectrograph HERMES (High
Efficiency and Resolution Mercator Echelle Spectrograph) attached to
the 1.2-m Mercator Telescope located on La Palma (Canary Islands,
Spain). The spectra have a resolving power R∼85000 and cover
the spectral range from 3770 to 9000Å. The typical signal-to-noise
(S/N) ratio for an individual spectrum at 5500Å is 80-100.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 121 152 Journal of spectroscopic observations and the
derived spectral classes
table3.dat 86 116 *Atmospheric parameters of investigated
Kepler A- and F-type stars
table4.dat 25 4292 Abundances of chemical elements for a sample
of analysed stars
notes.dat 80 128 Notes
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Note on table3.dat: Photometric values (KIC), those obtained from spectral
energy distributions (Na & SED) and from analysis of metal and Balmer lines
are presented.
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC KIC number
9 A1 --- n_KIC [*] * indicates a note in notes.dat file
11- 30 A20 --- Obs.date Date of observation
32- 36 F5.2 mag Vmag ? V magnitude
38- 43 A6 --- SpType1 Spectral type from the literature
45- 46 I2 --- Nsp ? Number of available spectra
48- 78 A31 --- SpType2 Spectral type obtained in this work (1)
80-121 A42 --- Notes Additional information taken from spectra
and Kepler data (2)
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Note (1): Additional notations for luminosity class:
"b" - lower luminosity main-sequence star
"a" or "a+" - higher luminosity main-sequence star
"IV-V" - between IV and V; "IV/V" - either IV or V
"n" - nebulous (i.e. broad-lined)
"s" - sharp lines
"nn" - very rapid rotators
"wk" met - weak metal lines
"met str" - strong metal lines
Note (2): Additional information taken from spectra and Kepler data:
"SB2" means double-lined spectroscopic binary
"rot." - rotational frequency detected
"bin." - orbital frequency detected
"mult." - orbital frequencies of both components detected
"hybrid" - frequencies of γ Dor and δ Sct visible in the spectra
"contamination" - Kepler data contaminated by a nearby star
"?" - our classification of variability type is uncertain.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC KIC Number
10- 13 I4 K Teff ?=- Effective temperature (from KIC)
15- 18 F4.2 [cm/s2] logg ?=- Surface gravity (from KIC)
20- 23 F4.2 mag E(B-V) ?=- Interstellar redenning (from KIC)
25- 28 F4.2 [-] logeps(Fe) ?=- Fe abundance (from KIC)
30- 33 F4.2 mag E(B-V)2 ?=- Interstellar redenning
(from NaD & SED)
35- 39 I5 K Teff2 Effective temperature (from NaD & SED)
41- 43 I3 K e_Teff2 rms uncertainty on Teff2
45- 49 I5 K Teff3 Effective temperature
(from metal and Balmer lines)
51- 53 I3 K e_Teff3 rms uncertainty on Teff3
55- 57 F3.1 [cm/s2] logg3 Surface gravity
(from metal and Balmer lines)
59- 61 F3.1 [cm/s2] e_logg3 rms uncertainty on logg3
63- 65 F3.1 km/s vt3 Microturbulent velocity
(from metal and Balmer lines)
67- 69 F3.1 km/s e_vt3 rms uncertainty on vt
71- 73 I3 km/s vsini3 Rotational velocity
(from metal and Balmer lines)
75- 76 I2 km/s e_vsini3 rms uncertainty on vsini3
78- 81 F4.2 [-] logeps(Fe)3 Fe abundance
(from metal and Balmer lines)
83- 86 F4.2 [-] e_logeps(Fe)3 rms uncertainty on logeps(Fe)3
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC KIC number
10- 11 A2 --- El Element
13- 16 F4.2 --- Abund ? Mean abundance
18- 21 F4.2 --- e_Abund ? Standard deviation of Abund
23- 25 I3 --- N ? Number of analysed parts
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Byte-by-byte Description of file: notes.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC KIC number
10- 80 A71 --- Note Text of the note
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 11-Dec-2015