J/A+A/512/A13 EW-Teff calibration for solar-type stars (Sousa+, 2010)
An effective temperature calibration for solar type stars using equivalent width
ratios. A fast and easy spectroscopic temperature estimation.
Sousa S.G., Alapini, A., Israelian G., Santos N.C.
<Astron. Astrophys. 512, A13 (2010)>
=2010A&A...512A..13S 2010A&A...512A..13S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, fundamental ; Spectroscopy ; Effective temperatures ;
Equivalent widths
Keywords: methods: data analysis - techniques: spectroscopy -
stars: fundamental parameters - planets and satellites: formation -
solar neighborhood
Abstract:
The precise determination of the stellar effective temperature of
solar type stars is of extreme importance for Astrophysics. We present
an effective temperature calibration for FGK dwarf stars using line
equivalent width ratios of spectral absorption lines.
The ratios of spectral line equivalent width can be very sensitive to
effective temperature variations for a well chosen combination of
lines. We use the automatic code ARES to measure the equivalent width
of several spectral lines, and use these to calibrate with the precise
effective temperature derived from spectroscopy presented in a
previous work.
Description:
Table 2 contains the information for the EW line-ratio calibrations.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 24 498 Line list
table2.dat 89 433 EW line-ratio calibration coefficients
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See also:
J/A+A/458/873 : Stellar parameters of metal-rich solar-type stars (Sousa+ 2007)
J/A+A/469/783 : Code for automatic determination of EW (ARES) (Sousa+, 2007)
J/A+A/487/373 : Spectroscopic parameters of 451 HARPS-GTO stars (Sousa+, 2008)
J/A+A/497/563 : Chemical abundances of 451 stars (Neves+, 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 F7.2 0.1nm lambda Central wavelength
9- 12 F4.2 eV EP Excitation potential
14- 19 F6.3 [-] loggf Oscilator strength
21- 24 A4 --- El Element
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- nf ID number of final line ratios
5- 7 I3 --- ni ID number of the initial list of line ratios
9- 11 I3 --- stddev standard deviation in each calibration
13- 15 I3 --- Nstars Number of stars used in each ratio calibration
17- 23 F7.2 0.1nm lambda1 Wavelength of first line
25- 31 F7.2 0.1nm lambda2 Wavelength of second line
33- 36 A4 --- El1 Element of first line
38- 41 A4 --- El2 Element of second line
43- 50 F8.2 --- c0 1st coefficient of the fit c0+c1x+c2x2+c3x3
52- 59 F8.2 --- c1 2nd coefficient of the fit c0+c1x+c2x2+c3x3
61- 68 F8.2 --- c2 3rd coefficient of the fit c0+c1x+c2x2+c3x3
70- 77 F8.2 --- c3 4th coefficient of the fit c0+c1x+c2x2+c3x3
79- 82 I4 K Teff0 Lower limit in Teff for each calibration
84- 87 I4 K Teff1 Upper limit in Teff for each calibration
89 I1 --- T [1/6] Type of fit used (1)
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Note (1): Fit type code as follows:
1 = relation "Teff versus r", straight line function
2 = relation "Teff versus r", 3rd order polynomial functions
3 = relation "Teff versus 1/r", but the spectral lines are inverted
in this table for ease of use, straight line function
4 = relation "Teff versus 1/r", but the spectral lines are inverted
in this table for ease of use, 3rd order polynomial functions
5 = relation "Teff versus log(r)" , straight line function
6 = relation "Teff versus log(r)" , 3rd order polynomial functions
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Acknowledgements:
Sergio G. Sousa, sousasag(at)astro.up.pt
(End) Sergio Sousa [CAUP-Porto, Portugal], Patricia Vannier [CDS] 19-Jan-2010