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J/A+A/531/A165      MILES atmospheric parameters           (Prugniel+, 2011)

Atmospheric parameters and spectral interpolator of the MILES stars. Prugniel P., Vauglin, I., Koleva M. <Astron. Astrophys. 531, A165 (2011)> =2011A&A...531A.165P
ADC_Keywords: Stars, atmospheres ; Atlases ; Effective temperatures ; Abundances, [Fe/H] Keywords: stars: fundamental parameters - galaxies: stellar content - stars: abundances Abstract: Empirical libraries of stellar spectra are used to classify stars and synthetize stellar populations. MILES is a medium spectral-resolution library in the optical domain covering a wide range of temperatures, surface gravities and metallicities. We redetermine the atmospheric parameters of these stars in order to improve the homogeneity and accuracy. We build an interpolating function that returns a spectrum as a function of the three atmospheric parameters, and finally we characterize the precision of the wavelength calibration and stability of the spectral resolution. We used the ULySS program with the ELODIE library as a reference and compared the results with those in the literature. Results. We obtain precisions of 60K, 0.13, and 0.05dex, respectively, for Teff, logg, and [Fe/H] for the FGK stars. For the M stars, the mean errors are 38K, 0.26, and 0.12dex and 3.5%, 0.17, and 0.13dex for the OBA. We construct an interpolator that we test against the MILES stars themselves. We test it also by measuring the atmospheric parameters of the CFLIB stars with MILES as reference and find it to be more reliable than the ELODIE interpolator for the evolved hot stars, like those of the blue horizontal branch in particular. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file param.dat 82 985 Physical parameters adopted by this work (table 1 of the paper) refs.dat 90 57 References ebv_cor.dat 10 55 *Extinction corrections for some stars miles_tgm.fits 2880 417 MILES interpolator FITS file
Note on ebv_cor.dat: As explained in Sect. 3.3.1 of the paper, the original shape of the SED was corrected for 55 stars, assuming that the residuals to the average library was due to an inaccurate correction of the Galactic extinction. The table gives the 'extinction' spectroscopically measured on the original MILES spectra (which were already corrected for a Galactic extinction). Therefore, these value are NOT real extinctions.
See also: III/218 : ELODIE archive (Prugniel+, 2001) J/ApJS/152/251 : Indo-US library of coude feed stellar spectra (Valdes+, 2004) http://www.noao.edu/cflib : Indo-US library of coude feed stellar spectra http://ulyss.univ-lyon1.fr/ : ULySS software package home page http://www.obs.u-bordeaux1.fr/m2a/soubiran/elodie_library.html : ELODIE home page Description of file: miles_tgm.fits -------------------------------------------------------------------------------- MILES spectral interpolator This FITS file contains the coefficients of the interpolator, which allows one to compute an interpolated spectrum, giving an effective temperature, log of surface gravity and metallicity (Teff, logg, and [Fe/H]). The file consists of three extensions containing the three temperature regimes described in the paper. Extension Teff range 0 warm 4000-9000K 1 hot >7000K 2 cool <4550K The three functions are linearly interpolated in the Teff overlapping regions. Each extension contains a 2D image-type array, whose first axis is the wavelength described by a WCS (Air wavelength, starting at 3536Å, step=0.9Å). The second axis contains the coefficients of the polynomial development as described in the paper (there is an undocumented normalization of the variables). This FITS files can be used by the ULySS package (see this package for an illustration of the usage of this file). Byte-by-byte Description of file: param.dat
Bytes Format Units Label Explanations
1- 23 A23 --- Name Designation of the star 26- 28 I3 --- Miles [1/985] Internal number in MILES 30- 34 I5 K Teff Effective temperature 36- 39 I4 K e_Teff ?=9999 Error on Teff 41- 45 F5.2 [cm/s2] logg ?=9.99 Log of the surface gravity 47- 50 F4.2 [cm/s2] e_logg ?=9.99 Error on logg 52- 56 F5.2 [Sun] [Fe/H] ?=9.99 Metallicity 58- 61 F4.2 [Sun] e_[Fe/H] ?=9.99 Error on [Fe/H] 63- 65 I3 km/s cz ?=999 Residual velocity shift (1) 67- 69 I3 km/s sig ?=999 Instrumental+physical broadening (2) 71- 82 A12 --- Refs ?=0 References for the adopted parameters, in refs.dat file (0=this work)
Note (1): cz is the mean residual velocity shift resulting from the fit to the Elodie interpolator. The shift may not be uniform throughout the spectrum, because of uncertainties in the wavelength calibration of MILES Note (2): sig is the Gaussian width of the absolute LSF at 5300Å. It includes the (variable) instrumental broadening and the physical broadening (rotation).
Byte-by-byte Description of file: refs.dat
Bytes Format Units Label Explanations
1- 2 A2 --- Ref Reference code 4- 22 A19 --- BibCode BibCode 24- 47 A24 --- Aut Author's name 51- 90 A40 --- Com Comments
Byte-by-byte Description of file: ebv_cor.dat
Bytes Format Units Label Explanations
1- 3 I3 --- Miles [1/985] Internal number in MILES 6- 10 F5.2 mag ebvCorr Correction applied to the original SED
Acknowledgements: Philippe Prugniel, prugniel(at)obs.univ-lyon1.fr
(End) Patricia Vannier [CDS] 01-Jul-2011
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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