VI/134 Grids of ATLAS9 Model Atmospheres and MOOG spectra (Kirby, 2011)
Grids of ATLAS9 Model Atmospheres and MOOG Synthetic Spectra
Kirby E.N.
<Publ. Astron. Soc. Pacific (2011)>
=2011yCat.6134....0K 2011yCat.6134....0K
ADC_Keywords: Models, atmosphere; Spectroscopy
Keywords: stars: atmospheres
Abstract:
A grid of ATLAS9 model atmospheres has been computed, spanning Teff
in 3500--8000K, log.g in 0.0--5.0, [Fe/H] in -4.0--0.0, [α/Fe]
in -0.08--1.2. These parameters are appropriate for stars in the red
giant branch, subgiants, and the lower main sequence. The main
difference from a previous, similar grid (Castelli & Kurucz 2003,
"Modelling of Stellar Atmospheres", 210, 0405087) is the
range of [α/Fe] values. A grid of synthetic spectra, calculated
from the model atmospheres, is also presented. The fluxes are computed
every 0.02Å from 630nm to 910nm. The microturbulent velocity
is given by a relation to the surface gravity. This relation is
appropriate for giants, but not for subgiants or dwarfs. Therefore,
caution is urged for the synthetic spectra with log.g>3.5.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
params.dat 96 316848 Summary of parameters used for synthetic spectra
atlas9/* . 316848 Synthetic spectra as FITS files (see Note (1))
sp/* . 139104 Atmosphere models in ATLAS9 format (see Note(2))
--------------------------------------------------------------------------------
See also:
VI/77 : Theoretical Stellar Fluxes (Kurucz+Buser, 1994)
VI/78 : Theoretical Stellar Flux Spectra for F- to K-type Stars (Buser+ 1992)
VI/120 : High-resolution synthetic stellar library (Coelho+, 2005)
Byte-by-byte Description of file: params.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 6 I5 K Teff [3500,8000] Effective temperature
8- 11 F4.1 [cm/s2] log.g [0,5] Surface gravity
13- 16 F4.1 [Sun] [Fe/H] [-4,0] Metallicity [Fe/H]
18- 21 F4.1 [Sun] [a/Fe] [-0.8,1.2] α-elements enhancement
23- 39 A17 --- SpFile Name of FITS file with 630-910nm spectrum,
in a subdirectory of "sp" (1)
44 I1 km/s xi1 ? Microturbulence velocity used in model1 (3)
45 A1 --- --- [=]
46- 69 A24 --- AtFile1 File in ATLAS9 format corresponding to model1,
in a subdirectory of "atlas9" (2)
71 I1 km/s xi2 ? Microturbulence velocity used in model2 (3)
72 A1 --- --- [=]
73- 96 A24 --- AtFile2 File in ATLAS9 format corresponding to model2,
in a subdirectory of "atlas9" (2)
--------------------------------------------------------------------------------
Note (1): the "sp" subdirectory is a tree where the first level is the
temperature and the second level the gravity; for instance the value
of "SpFile" corresponding to Teff=3500, log.g=0, [Fe/H]=0, [alpha]=0
is "t3500g00f00a_00", and the corresponding file can be found as
sp/t3500/g00/t3500g00f00a00.fits.bz2 (bzip2 compression; the
suffix ".fits.bz2" being omitted in SpFile)
Note (2): the "atlas9" is a tree organized by metallicities and
α-element enhancement. For instance, the value of "AtFile1"
corresponding to Teff=3500, log.g=0, [Fe/H]=0, [alpha]=0, and ξ=2
is "ap00t3500g00k2odfnew" and the corresponding file can be found as
atlas9/p00/ap00t3500g00k2odfnew.dat (the suffix ".dat" is omitted).
A description of the ATLAS9 format can be found at
http://www1.appstate.edu/dept/physics/spectrum/doc/node12.html
Note (3): These microturbulent values are used for the model atmospheres
only. The microturbulent velocities of the spectra are fixed to the
surface gravity: ξ = 2.13 - 0.23*log.g
--------------------------------------------------------------------------------
History:
27-Jan-2011: from Evan Kirby, Caltech Institute
(End) Francois Ochsenbein [CDS] 22-Jan-2011