J/A+A/661/A76 Spectra interpolation expansion coeff. (Bertran de Lis+, 2022)
Interpolation of spectra from 3D model atmospheres.
Bertran de Lis S., Allende Prieto C., Ludwig H.-G., Koesterke L.
<Astron. Astrophys. 661, A76 (2022)>
=2022A&A...661A..76B 2022A&A...661A..76B (SIMBAD/NED BibCode)
ADC_Keywords: Models ; Spectroscopy
Keywords: radiative transfer - techniques: spectroscopic - catalogs -
stars: atmospheres
Abstract:
The use of 3D hydrodynamical simulations of stellar surface convection
and spectral synthesis calculations as model atmosphere is
computationally expensive. Although these models have been available
for quite some time, its use is limited due to the lack of extensive
grids of simulations and associated spectra.
Our goal is to provide a method to interpolate spectra that can be
applied to both 1D and 3D models, and implement it in a code available
to the community. This tool will enable the routine use of 3D model
atmospheres in the analysis of stellar spectra.
We have developed a code that makes use of Radial Basis Functions to
interpolate the spectra included in the CIFIST grid of 84
three-dimensional model atmospheres. Spectral synthesis on the
hydrodynamical simulations was previously performed with the code
ASSeT.
We make available to the community a tool for the interpolation of 3D
spectra. The code provides interpolated spectra and interpolation
errors for a given wavelength interval, and a combination of effective
temperature, surface gravity, and metallicity. In addition, it
optionally provides graphical representations of the RMS and mean
ratio between 1D and 3D spectra, and maps of the errors in the
interpolated spectra across the parameter space.
Description:
The following text describes the code and data files available from
https://cloud.iac.es/index.php/s/LKYXfYXtbqAKNfx
The line lists used in the model spectra are available from
https://cloud.iac.es/index.php/s/pqJ9cwtJ9GSBraz
The code is written in IDL and works on GDL as well. The main program
is inter.pro. Auxiliary routines are included in the files
rbf_eval.pro and gconv.pro.
The final grid of 3D models comprises 84 simulations with
different combinations of surface gravity, chemical composition, and
entropy flux at the bottom of the atmosphere.
For each 3D model, a 1D hydrostatic model of atmosphere was also
derived by linear interpolation of the ODFNEW model grid by Castelli &
Kurucz (2004, 0405087), which was also based on the solar
abundances of Grevesse & Sauval (1998, Space Sci. Rev., 85, 161).
The data files are w1d.fits, w3d1derr.fits, and w3d1d.fits. They
contain expansion coefficients for interpolation with Radial Basis
Functions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 111 6 List of files
inter.pro 127 348 Main program
gconv.pro 81 144 Auxiliary routine for inter.pro
rbf_eval.pro 72 61 Auxiliary routine for inter.pro
w1d.fits 2880 486824 Expansion coefficients for interpolation of 1D
spectra with Radial Basis Functions
w3d1d.fits 2880 486824 Expansion coefficients for interpolation of
3D/1D ratios with Radial Basis Functions
w3d1derr.fits 2880 486824 Expansion coefficient for interpolation of errors
in the 3D/1D ratios with Radial Basis Functions
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- FileName Name of the file
15-111 A97 --- Title Title of the file
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Acknowledgements:
Carlos Allende Prieto, callende(at)iac.es
(End) Patricia Vannier [CDS] 17-Feb-2022