MSG Grid Files
Multidimensional Spectral Grids (MSG) is a software package for interpolating spectra and colors in pre-computed grids. Due to their large size and gradually evolving content (as improvements are made), grid data files files are not shipped as part of the MSG git repository; rather, they are hosted separately on this page.
OSTAR2002 Grids
The OSTAR2002 grids are based on the line-blanketed O-star model atmospheres published in Lanz & Hubeny (2003). Spectra are calculated from these atmospheres using SYNSPEC, and their angle dependence parameterized with the CLARET limb-darkening law.
File | Current Version | Old Versions | Resolution | λ Range | Photospheric Parameters |
---|---|---|---|---|---|
sg-OSTAR2002-low.h5 (50MB) | v1 | — | R=1000 | [880Å, 5μm] | Teff, log(g), Z/Zo |
sg-OSTAR2002-medium.h5 (447MB) | v1 | — | R=10000 | [880Å, 5μm] | Teff, log(g), Z/Zo |
sg-OSTAR2002-high.h5 (4.2GB) | v1 | — | R=100000 | [880Å, 5μm] | Teff, log(g), Z/Zo |
The definitions and ranges of the photospheric parameters are as follows:
- effective temperature Teff = Teff/K ∈ [27500, 55000]
- surface gravity log(g) = log10(g/cm s-2) ∈ [3.0, 4.75]
- metallicity Z/Zo = Z/Z☉ ∈ [0.02, 2]
BSTAR2006 Grids
The BSTAR2006 grids are based on the line-blanketed B-star model atmospheres published in Lanz & Hubeny (2007). Spectra are calculated from these atmospheres using SYNSPEC, and their angle dependence parameterized with the CLARET limb-darkening law.
File | Current Version | Old Versions | Resolution | λ Range | Photospheric Parameters |
---|---|---|---|---|---|
sg-BSTAR2006-low.h5 (77MB) | v1 | — | R=1000 | [880Å, 5μm] | Teff, log(g), Z/Zo |
sg-BSTAR2006-medium.h5 (693MB) | v1 | — | R=10000 | [880Å, 5μm] | Teff, log(g), Z/Zo |
sg-BSTAR2006-high.h5 (6.5GB) | v1 | — | R=100000 | [880Å, 5μm] | Teff, log(g), Z/Zo |
The definitions and ranges of the photospheric parameters are as follows:
- effective temperature Teff = Teff/K ∈ [15000, 30000]
- surface gravity log(g) = log10(g/cm s-2) ∈ [1.75, 4.75]
- metallicity Z/Zo = Z/Z☉ ∈ [0, 2]
C3K Grids
The C3K grids are based on the data described in section 5.4 of Choi et a. (2016), kindly shared by the MIST team. The angle dependence of spectra is parameterized with the CONST limb-darkening law.
Note: currently there are some voids in the C3K grids that can cause interpolation to fail. We are looking into ways to repair these holes, and will release a new set of grids if successful.
File | Current Version | Old Versions | Resolution | λ Range | Photospheric Parameters |
---|---|---|---|---|---|
sg-C3K-coarse.h5 (1.5GB) | v1 | — | Variable; R=3000 in optical |
[100Å, 9000Å] | Teff, log(g), [Fe/H], [alpha/Fe] |
The definitions and ranges of the photospheric parameters are as follows:
- effective temperature Teff = Teff/K ∈ [2500, 46000]
- surface gravity log(g) = log10(g/cm s-2) ∈ [-1.0, 5.5]
- metallicity [Fe/H] = log10[(Fe/H)/(Fe/H)☉] ∈ [-2.5, 0.5]
- alpha enhancement [alpha/Fe] = log10[(α/Fe)/(α/Fe)☉] ∈ [-0.2, 0.6]
CAP18 Grids
The CAP18 grids are based on the data published in Allende Prieto et al. (2018) (the letters ‘CAP’ are the initials of the first author). The angle dependence of spectra is parameterized with the CONST limb-darkening law.
File | Current Version | Old Versions | Resolution | λ Range | Photospheric Parameters |
---|---|---|---|---|---|
sg-CAP18-large.h5 (73GB) | v2 | v1 | R=10000 | [1300Å, 6.5μm] | Teff, log(g), [Fe/H], [alpha/Fe], log(xi) |
sg-CAP18-coarse.h5 (339MB) | v2 | v1 | R=10000 | [1300Å, 6.5μm] | Teff, log(g), [Fe/H] |
sg-CAP18-high.h5 (2.9GB) | v2 | v1 | R=100000 | [1300Å, 6.5μm] | Teff, log(g), [Fe/H] |
sg-CAP18-ultra.h5 (5.2GB) | v2 | v1 | R=300000 | [1300Å, 6.5μm] | Teff, log(g), [Fe/H] |
The definitions and ranges of the photospheric parameters are as follows:
- effective temperature Teff = Teff/K ∈ [3500, 30000]
- surface gravity log(g) = log10(g/cm s-2) ∈ [0.0, 5.0]
- metallicity [Fe/H] = log10[(Fe/H)/(Fe/H)☉] ∈ [-5.0, 0.5]
- alpha enhancement [alpha/Fe] = log10[(α/Fe)/(α/Fe)☉] ∈ [-1.0, 1.0]
- microturbulent velocity log(xi) = log10(ξ/cm s-1) ∈ [-0.301, 0.903]
Coelho14 Grids
The Coelho14 grids are based on the data described in Coelho (2014) and available for download from specmodels.iag.usp.br/. The angle dependence of spectra is parameterized with the CONST limb-darkening law.
File | Current Version | Old Versions | Resolution | λ Range | Photospheric Parameters |
---|---|---|---|---|---|
sg-Coelho14-HighRes.h5 (2.1GB) | v1 | — | Δλ=0.02Å | [2500Å, 9000Å] | Teff, log(g), [Fe/H], [alpha/Fe] |
sg-Coelho14-SED.h5 (32MB) | v1 | — | R=518 | [1300Å, 100μm] | Teff, log(g), [Fe/H], [alpha/Fe] |
The definitions and ranges of the photospheric parameters are as follows:
- effective temperature Teff = Teff/K ∈ [3000, 22000]
- surface gravity log(g) = log10(g/cm s-2) ∈ [-0.5, 5.5]
- metallicity [Fe/H] = log10[(Fe/H)/(Fe/H)☉] ∈ [-1.0, 0.2]
- alpha enhancement [alpha/Fe] = log10[(α/Fe)/(α/Fe)☉] ∈ [0, 0.4]
Göttingen Grids
The Göttingen grids are based on the data described in Husser et al. (2013) and available for download from phoenix.astro.physik.uni-goettingen.de. The angle dependence of spectra is parameterized with the CONST limb-darkening law.
Alpha-dependent Grids
File | Current Version | Old Versions | Resolution | λ Range | Photospheric Parameters |
---|---|---|---|---|---|
sg-Goettingen-HiRes-alpha.h5 (96GB) | v3 | — | variable | [500Å, 5.5μm] | Teff, log(g), [Fe/H], [alpha/Fe] |
sg-Goettingen-MedRes-A-alpha.h5 (4.9GB) | v3 | — | Δλ=1Å (×10 oversampled) |
[3000Å, 1μm] | Teff, log(g), [Fe/H], [alpha/Fe] |
sg-Goettingen-MedRes-R-alpha.h5 (15GB) | v3 | — | R=10000 (×10 oversampled) |
[3000Å, 2.5μm] | Teff, log(g), [Fe/H], [alpha/Fe] |
The definitions and ranges of the photospheric parameters are as follows:
- effective temperature Teff = Teff/K ∈ [3500, 8000]
- surface gravity log(g) = log10(g/cm s-2) ∈ [0.0, 6.0]
- metallicity [Fe/H] = log10[(Fe/H)/(Fe/H)☉] ∈ [-3.0, 0.0]
- alpha enhancement [alpha/Fe] = log10[(α/Fe)/(α/Fe)☉] ∈ [-0.2, 1.2]
Solar-alpha Grids
File | Current Version | Old Versions | Resolution | λ Range | Photospheric Parameters |
---|---|---|---|---|---|
sg-Goettingen-HiRes.h5 (32GB) | v3 | v2 | variable | [500Å, 5.5μm] | Teff, log(g), [Fe/H] |
sg-Goettingen-MedRes-A.h5 (1.7GB) | v3 | v2 | Δλ=1Å (×10 oversampled) |
[3000Å, 1μm] | Teff, log(g), [Fe/H] |
sg-Goettingen-MedRes-R.h5 (4.8GB) | v3 | v2 | R=10000 (×10 oversampled) |
[3000Å, 2.5μm] | Teff, log(g), [Fe/H] |
The definitions and ranges of the photospheric parameters are as follows:
- effective temperature Teff = Teff/K ∈ [2300, 12000]
- surface gravity log(g) = log10(g/cm s-2) ∈ [0.0, 6.0]
- metallicity [Fe/H] = log10[(Fe/H)/(Fe/H)☉] ∈ [-4.0, 1.0]
SPHINX Grids
The SPHINX grids are based on the data described in Iyer et al. (2023) and available for download from zenodo.org/record/7416042. The angle dependence of spectra is parameterized with the CONST limb-darkening law.
File | Current Version | Resolution | λ Range | Photospheric Parameters |
---|---|---|---|---|
sg-SPHINX.h5 (113MB) | v1 | R=250 | [1000Å, 19.9μm] | Teff, log(g), [F/H], C/O |
The definitions and ranges of the photospheric parameters are as follows:
- effective temperature Teff = Teff/K ∈ [2000, 4000]
- surface gravity log(g) = log10(g/cm s-2) ∈ [4.0, 5.5]
- metallicity [Fe/H] = log10[(Fe/H)/(Fe/H)☉] ∈ [-1.0, 1.0]
- carbon-to-oxygen C/O = NC/NO ∈ [0.3, 0.9]