J/A+A/404/689 Metallicities of Slowly Pulsating B stars (Niemczura+, 2003)
Metallicities of the SPB stars from the IUE ultraviolet spectra.
Niemczura E.
<Astron. Astrophys. 404, 689 (2003)>
=2003A&A...404..689N 2003A&A...404..689N
ADC_Keywords: Stars, early-type ; Stars, B-type ; Abundances ;
Spectra, ultraviolet
Keywords: stars: early-type - stars: abundances - stars: variables: general
Abstract:
We derived the stellar parameters (angular diameters, effective
temperatures, metallicities) and interstellar reddenings for
20 Slowly Pulsating B (SPB) and 34 reference stars observed during the
IUE satellite mission. The parameters were derived by means of an
algorithmic procedure of fitting theoretical flux distributions to the
low-resolution IUE spectra and optical spectrophotometric
observations. Since the metallicity [m/H] has a special importance for
pulsating B type stars, we focused our attention on that parameter. We
found that the mean value of the metallicity of the considered SPB and
reference stars amounts to [m/H]~-0.20. The results only slightly
depend on the reduction procedure used for the IUE images (NEWSIPS and
INES). The metal abundances obtained in this paper are in accordance
with the average value of -0.2dex for stars in the solar neighborhood
recently reported by other investigators.
Description:
The observational material consists of the IUE observations obtained
with the large and small apertures from both the long-wavelength (LWP
and LWR, 1950-3200Å) and the short-wavelength (SWP, 1100-1950Å)
cameras with high (0.1-0.3Å) and low (6-7Å) spectral
resolutions. We used observations processed by two reduction packages:
the IUE/NEWSIPS (New Spectral Image Processing System,) and IUE/INES
(IUE Newly Extracted Spectra)
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 53 54 Star positions and magnitudes (from Simbad)
table3.dat 99 40 The best-fit parameters for the SPB stars
obtained from IUE/NEWSIPS low resolution data
table4.dat 99 40 The best-fit parameters for the SPB stars
obtained from IUE/INES low resolution data
table5.dat 99 68 The best-fit parameters for the reference stars
table6.dat 72 28 The parameters specifying the shape of the UV
extinction curves of SPB and reference stars
table7.dat 46 55 Mean correlation coefficients. All results were
obtained from the IUE/NEWSIPS spectra
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See also:
VI/99 : Merged Log of IUE Observations (NASA-ESA, 1999)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- --- [HD]
4- 9 I6 --- HD HD number
13- 14 I2 h RAh Right ascension (J2000.0)
16- 17 I2 min RAm Right ascension (J2000.0)
19- 22 F4.1 s RAs Right ascension (J2000.0)
24 A1 --- DE- Declination sign (J2000.0)
25- 26 I2 deg DEd Declination (J2000.0)
28- 29 I2 arcmin DEm Declination (J2000.0)
31- 32 I2 arcsec DEs Declination (J2000.0)
36- 40 F5.2 mag Bmag ? B magnitude
42- 46 F5.2 mag Vmag ? V magnitude
48- 68 A21 --- SpType Spectral type
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Byte-by-byte Description of file: table3.dat table4.dat table5.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD HD number of the star
8 A1 --- Data [bmni] Type of data (1)
10- 14 F5.3 K logTeff Effective temperature
17- 21 F5.3 K e_logTeff The Error of the effective temperature
24- 27 F4.2 --- logg Gravity
30- 34 F5.2 Sun [m/H] The Metallicity
37- 40 F4.2 --- e_[m/H] The Error of the metallicity
43- 47 F5.3 mas theta Stellar diameter
50- 54 F5.3 mas e_theta The error of the stellar diameter
57- 61 F5.3 mag E(B-V) Interstellar extinction
64- 68 F5.3 mag e_E(B-V) The error of the interstellar extinction
71- 76 F6.3 --- S1 The S1 parameter (2)
79- 83 F5.3 --- e_S1 The error of the S1 parameter
86- 91 F6.3 --- S2 The S2 parameter (2)
94- 98 F5.3 --- e_S2 The error of the S2 parameter
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Note (1): Type of data:
b: best-fit parameters together with the formal errors
m: median values from the bootstrap resampling of each parameter
together with 1σ uncertainties
n: parameters obtained from IUE/NEWSIPS low resolution data
i: parameters obtained from IUE/INES low resolution data
Note (2): The parameters S1 and S2 adjust the short- and long-wavelength parts
of IUE spectra to the visual flux level (F*S1*S2). Outside the IUE/SWP
region we put S1=1, whereas S2=1 is set outside the wavelength region
covered by the long-wavelength IUE observations.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- HD HD number of the star
8- 9 A2 --- Data [brn iue] Type of data (1)
11- 14 F4.2 --- gamma Width, gamma (mean = 0.99) (2)
17- 20 F4.2 --- e_gamma The error of gamma
23- 27 F5.3 --- x0 Position, x0 (mean = 4.596) (2)
30- 34 F5.3 --- e_x0 The error of x0
37- 41 F5.3 --- c2 Linear term, c2 (mean = 0.698) (2)
44- 48 F5.3 --- e_c2 The error of c2
51- 54 F4.2 --- c3 Strenth, c3 (mean = 3.23) (2)
57- 60 F4.2 --- e_c3 The error of c3
63- 66 F4.2 --- c4 Far-UV curvature term, c4 (mean = 0.41) (2)
69- 72 F4.2 --- e_c4 The error of c4
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Note (1): Type of data:
bn: best-fit resampling results for IUE/NEWSIPS spectra
rn: bootstrap resampling results for IUE/NEWSIPS spectra
iu: results for IUE observations
in: results for INES observations
n: best-fit solutions for IUE/NEWSIPS data for reference stars
i: best-fit solutions for IUE/INES data for reference stars
Note (2): The parameters of the mean extinction curve (Fitzpatrick,
1999PASP..111...63F 1999PASP..111...63F) are given for comparison.
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- P1 The first parameter designation (1)
8- 15 A8 --- P2 The second parameter designation (1)
17- 20 F4.2 --- rhoMean Mean correlation coefficients
23- 26 F4.2 --- sigmarho Standard deviations
29- 32 F4.2 --- rhoMedian Median values of correlations
35- 38 F4.2 --- rhoMedianMax The largest values of rhoMedian
41- 44 F4.2 --- rhoMedianMin The lowest values of rhoMedian
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Note (1): Correlations between the
E(B-V), S1, Teff, [m/H], c2, c3, c4, gamma, theta and x0 parameters
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Acknowledgements: Ewa Niemczura
(End) Patricia Bauer [CDS] 06-Jun-2003