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 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.
Description:
A further article, Sharma et al. (2016A&A...585A..64S 2016A&A...585A..64S, Cat.
J/A+A/585/A64) has improved the interpolator and the parameter
estimations for the stars cooler than 4800K. We recommend to use those
new parameters for the cool stars rather than those of the present
paper, and if necessary to connect the two datasets by interpolating
the parameters in the range 4500<Teff<4800.
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
J/A+A/585/A64 : New atmospheric parameters of MILES cool stars (Sharma+, 2016)
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