...2003a,b)[*]
This grid is available at http://tlusty.gsfc.nasa.gov
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... web[*]
http://www.usm.uni-muenchen.de/people/adi/Models/
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... shell[*]
For Uderived at the Strömgren radius without empty cavity one has $U \propto
(Q N_{\rm e} \epsilon^2)^{1/3}$, with the filling factor $\epsilon$.
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...)[*]
For their grids the ionization parameter U defined at the Strömgren radius vary actually by $\sim$0.1 (supergiant grid) and 0.3 dex (dwarfs).
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... III/II])[*]
The WM-Basic model at 35 kK shown here is an exception to this trend, however.
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... respectively[*]
However, note that e.g. any $\eta $ involving [Ar III/II] will likely depend on $\bar{U}$, as [Ar III/II] itself depends already little on $\bar{U}$.
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... models[*]
Note that the metallicity dependence predicted by the WM-Basic models is probably overestimated as already discussed earlier (Sect. 5.5).
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...$\eta_{\rm O-S}$[*]
Defined by Vilchez & Pagel (1988) as: ([O II] 3726,27 Å/ [O III] 4959,5007 Å) / ([S II] 6717,31 Å/[S III] 9069,9532 Å). 
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...$_\odot$[*]
Ne abundances were obtained using reddening and $T_{\rm elec}$ corrected abundances from Giveon et al. (2002a). Ne is preferred to Ar or S because Ar abundance is not reliable for high  ${T}_{{\rm eff}}$, Ar3+ being present but unobserved, the same applying at low ${T}_{{\rm eff}}$ for S+. The solar abundance for Ne is determined using the abundance gradient obtained by Giveon et al. (2002a) at 8.5 kpc.
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... spectra[*]
Presumably these differences are due to the use of different methods to treat line blanketing (opacity sampling method versus super-level approach in the comoving frame) and different atomic data.
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Copyright ESO 2004