This WEB interface allows to inspect and download synthetic spectra for Wolf-Rayet and OB stars. The spectra are calculated from PoWR model atmospheres which account for Non-LTE, spherical expansion and metal line blanketing.
The models are arranged in different Model Grids. Each model grid is characterized by a set of common parameters, such as stellar luminosity, terminal wind velocity, clumping contrast, and chemical composition. For Wolf-Rayet stars of the nitrogen subclass (WN) there are grids of hydrogen-free models (WNE) and of models with a specified mass fraction of hydrogen (WNL). The iron-group and total CNO mass fractions correspond to the metallicity of the Galaxy, the Large Magellanic Cloud (LMC), or the Small Magellanic Cloud (SMC), respectively.
| log L | vfinal | Dmax | XH | XHe | XC | XN | XO | XNe | XFe | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| [Lsun] | [km/s] | mass fractions | ||||||||||
| Galactic Metallicity | ||||||||||||
| MW WNE | Details | 5.3 | 1600 | 4 | - | 0.98 | 1.0E-4 | 0.015 | - | - | 1.4E-3 | |
| MW WNL-H20 | Details | 5.3 | 1000 | 4 | 0.2 | 0.78 | 1.0E-4 | 0.015 | - | - | 1.4E-3 | |
| MW WNL-H50 | Details | 5.3 | 1000 | 4 | 0.5 | 0.48 | 1.0E-4 | 0.015 | - | - | 1.4E-3 | |
| MW WC | Details | 5.3 | 2000 | 10 | - | 0.55 | 0.4 | - | 0.05 | - | 1.6E-3 | |
| LMC Metallicity | ||||||||||||
| LMC WNE | Details | 5.3 | 1600 | 10 | - | 0.995 | 7.0E-5 | 4.0E-3 | - | - | 7.0E-4 | |
| LMC WNL-H20 | Details | 5.3 | 1000 | 10 | 0.2 | 0.795 | 7.0E-5 | 4.0E-3 | - | - | 7.0E-4 | |
| LMC WNL-H40 | Details | 5.3 | 1000 | 10 | 0.4 | 0.595 | 7.0E-5 | 4.0E-3 | - | - | 7.0E-4 | |
| LMC WC | Details | 5.3 | 2000 | 10 | - | 0.55 | 0.4 | - | 0.05 | 1.0E-3 | 7.0E-4 | |
| SMC Metallicity | ||||||||||||
| SMC WNE | Details | 5.3 | 1600‡ | 4 | - | 0.998 | 2.5E-5 | 1.5E-3 | - | - | 3.0E-4 | |
| SMC WNL-H20 | Details | 5.3 | 1600‡ | 4 | 0.2 | 0.798 | 2.5E-5 | 1.5E-3 | - | - | 3.0E-4 | |
| SMC WNL-H40 | Details | 5.3 | 1600‡ | 4 | 0.4 | 0.598 | 2.5E-5 | 1.5E-3 | - | - | 3.0E-4 | |
| SMC WNL-H60 | Details | 5.3 | 1600‡ | 4 | 0.6 | 0.398 | 2.5E-5 | 1.5E-3 | - | - | 3.0E-4 | |
| SMC WC | Details | 5.3 | 2000 | 10 | - | 0.547 | 0.4 | - | 0.05 | 2.4E-3 | 3.0E-4 | |
| sub-SMC Metallicity (0.07 solar) | ||||||||||||
| Z0.07 WNE | Details | 5.3 | 1600 | 10 | - | 0.999 | 1.0E-5 | 6.1E-4 | 1.0E-5 | - | 9.2E-5 | |
| Z0.07 WNL-H20 | Details | 5.3 | 1600 | 10 | 0.2 | 0.799 | 1.0E-5 | 6.1E-4 | 1.0E-5 | - | 9.2E-5 | |
| Z0.07 WNL-H40 | Details | 5.3 | 1600 | 10 | 0.4 | 0.599 | 1.0E-5 | 6.1E-4 | 1.0E-5 | - | 9.2E-5 | |
| Z0.07 WNL-H60 | Details | 5.3 | 1600 | 10 | 0.6 | 0.399 | 1.0E-5 | 6.1E-4 | 1.0E-5 | - | 9.2E-5 | |
| Z0.07 WC | Details | 5.3 | 2000 | 10 | - | 0.549 | 0.4 | - | 0.05 | 8.3E-4 | 9.2E-5 | |
‡ "Double beta-law", see WR model parameter details dropdown below
Each grid has a two-dimensional parameter space, namely the stellar temperature T and the "transformed radius" Rt. The latter is a function of the mass-loss rate and the stellar radius. Thanks to an approximate scaling invariance of WR atmospheres, the same model spectrum can be applied to stars with different luminosities, but same T and Rt. When doing so, the absolute fluxes must be scaled proportional to L, the radius R proportional to L1/2, and the mass-loss rate proportional to L3/4.
Calibrated line spectra improved (March 2025): For more recent models, the calibrated line spectra which are provided for preview or download became more accurate. For older models, the absolute fluxes are computed from the normalized spectra scaled with the model continuum (SED). This might cause a slight inconsistency of the flux level in the percent range. If still calculated the old way, a corresponding note is displayed in the box where the wavelength band is selected.
Bug warning (Feb. 2021): The H I Paschen line at about 8502 Angstroem (transition 3 - 16) appears shifted redwards by 2.4 Angstroem in all model spectra due to a mistake in the atomic data.
New (Oct. 2016): The WNL-H50 grid has been re-calculated in 2016; this latest version is shown by default. The previous version of the WNL-H50 grid can still be accessed by choosing "WNL-H50-2013" in the drop-down menu below.
New (Oct. 2016): The WNL grid has been re-calculated in 2016; this latest version is shown by default. The previous version of the WNL grid can still be accessed by choosing "WNL-2012" in the drop-down menu below.
New (Sept. 2016): The WNE grid has been re-calculated in 2016; this latest version is shown by default. The previous version of the WNE grid can still be accessed by choosing "WNE-2013" in the drop-down menu below.
Grids of models for O- and B-type stars are provided for solar metallicity, for a metallicity of 1/2 solar as appropriate for the Large Magellanic Cloud (LMC), and for a metallicity of 1/7 solar as appropriate for the Small Magellanic Cloud (SMC), respectively.
Each grid has a two-dimensional parameter space, namely the stellar temperature T and the surface gravity ggrav. The grid resolution is 1 kK for the stellar temperature and 0.2dex for the surface gravity, log g. Regarding the stellar wind, the different grids of OB-type stars which are provided have either a fixed mass-loss rate, a fixed log Q value (see "OB model parameter details" below for the definition of Q), or each model has a specific mass-loss rate as predicted from theoretical mass-loss recipes (see Table below). For more information about the individual grids click on "Details".
| T | log g | log M | log Q | Dmax | vturb | XH | XHe | XC | XN | XO | XNe | XMg | XAl | XSi | XP | XS | XFe | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| [kK] | [cgs] | [Msun/yr] | km/s | mass fractions | ||||||||||||||||
| Galactic Metallicity | ||||||||||||||||||||
| GAL-OB-Vd3 | Details | 15…56 | 2.0…4.2 | Vink et al. (2001) / 3 | 10 | 7 | 0.738 | 0.251 | 2.4E-3 | 6.9E-4 | 5.7E-3 | 1.3E-3 | 6.9E-4 | 5.3E-5 | 6.7E-4 | 5.8E-6 | 3.1E-4 | 1.2E-3 | ||
| OB-I | Details | 15…56 | 2.0…4.4 | -7 | 10 | 7 | 0.738 | 0.251 | 2.4E-3 | 6.9E-4 | 5.7E-3 | - | 6.9E-4 | - | 6.7E-4 | 5.8E-6 | 3.1E-4 | 1.2E-3 | ||
| LMC Metallicity | ||||||||||||||||||||
| LMC-OB-Vd3 | Details | 15…56 | 2.0…4.4 | Vink et al. (2001) / 3 | 10 | 7 | 0.738 | 0.258 | 4.7E-4 | 7.8E-5 | 2.6E-3 | 6.3E-4 | 2.1E-4 | 2.7E-5 | 3.2E-4 | 2.9E-6 | 1.5E-4 | 7.0E-4 | ||
| LMC-OB-I | Details | 15…50 | 2.0…4.4 | -7 | 10 | 7 | 0.738 | 0.258 | 4.7E-4 | 7.8E-5 | 2.6E-3 | - | 2.1E-4 | - | 3.2E-4 | 2.9E-6 | 1.5E-4 | 7.0E-4 | ||
| SMC Metallicity | ||||||||||||||||||||
| SMC-OB-Vd3 | Details | 15…57 | 2.0…4.4 | Vink et al. (2001) / 3 | 10 | 7 | 0.738 | 0.261 | 2.1E-4 | 3.3E-5 | 1.1E-3 | 3.2E-4 | 9.9E-5 | 1.3E-5 | 1.3E-4 | 8.3E-7 | 4.4E-5 | 3.5E-4 | ||
| SMC-OB-I | Details | 15…50 | 2.0…4.4 | moderate | -13.0 | 10 | 10 | 0.738 | 0.261 | 2.1E-4 | 3.3E-5 | 1.1E-3 | - | 9.9E-5 | - | 1.3E-4 | 8.3E-7 | 4.4E-5 | 3.5E-4 | |
| SMC-OB-II | Details | 15…50 | 2.0…4.4 | high | -12.0 | 10 | 10 | 0.738 | 0.261 | 2.1E-4 | 3.3E-5 | 1.1E-3 | - | 9.9E-5 | - | 1.3E-4 | 8.3E-7 | 4.4E-5 | 3.5E-4 | |
| SMC-OB-III | Details | 15…50 | 2.0…4.4 | low | -14.0 | 10 | 10 | 0.738 | 0.261 | 2.1E-4 | 3.3E-5 | 1.1E-3 | - | 9.9E-5 | - | 1.3E-4 | 8.3E-7 | 4.4E-5 | 3.5E-4 | |
| sub-SMC Metallicity (1/31 solar) | ||||||||||||||||||||
| subSMC-OB-Vd3 | Details | 15…62 | 2.0…4.4 | Vink et al. (2001) / 3 | 10 | 7 | 0.738 | 0.261 | 7.5E-5 | 2.2E-5 | 1.8E-4 | 4.1E-5 | 2.2E-5 | 1.7E-6 | 2.1E-5 | 1.8E-7 | 9.8E-6 | 3.8E-5 | ||
Calibrated line spectra improved (March 2025): For more recent models, the calibrated line spectra which are provided for preview or download became more accurate. For older models, the absolute fluxes are computed from the normalized spectra scaled with the model continuum (SED). This might cause a slight inconsistency of the flux level in the percent range. If still calculated the old way, a corresponding note is displayed in the box where the wavelength band is selected.
New (Jan. 2025): Two more grids of OB-star models have been added, for Galactic (named "Gal-OB-Vd3") and LMC (named "LMC-OB-Vd3") metallicity. Stellar masses and luminosities are based on underlying evolutionary tracks, and the mass-loss rates of the individual stars are adopted according to a theoretical recipe. For more information, see the respective Details page Gal-OB-Vd3 and LMC-OB-Vd3. Note that grids of models with individually (predicted) mass-loss rates are in particular apt for population synthesis, while the grids with different (fixed) mass-loss rates are needed to fit a specific observation in case the predicted mass-loss rate does not match.
New (Dec. 2024): A grid of OB-star models with sub-SMC metallicity has been added, named "subSMC-OB-Vd3". Stellar masses and luminosities are based on underlying evolutionary tracks, and the mass-loss rates of the individual stars are adopted according to a theoretical recipe. Find here more Details.
New (Feb. 2023): A new grid named SMC-OB-Vd3 has been added. Individual mass loss rates are adopted for each of the grid models (see more Details). Hence, this grid is most appropriate for population synthesis at SMC metallicity.
Bug warning (Feb. 2021): The H I Paschen line at about 8502 Angstroem (transition 3 - 16) appears shifted redwards by 2.4 Angstroem in all model spectra with fixed log M or log Q due to a mistake in the atomic data.
Bug warning (Feb. 2021): The S IV resonance line in the UV at 1062 - 1073 Angstroem is missing in all OB-type model spectra with fixed log M or log Q due to a mistake in the atomic data.
New (Aug. 2019): The grid SMC-OB-III (low mass-loss rates) has been added.