Figure 1: Left: observed EW (in Å) from Mathys (1988, 1989), Conti & Alschuler (1971), Conti & Frost (1977), Bisiacchi et al. (1982) are plotted with crosses for dwarfs, circles for giants and squares for supergiants. Typical errors in the observations are 5 to 10%. The solid lines show the maximum and minimum values predicted in our models. Right: equivalent width predictions for He I are plotted for dwarfs (crosses), giants (circles), supergiants (squares) and lower surface gravity supergiants (triangles). Small symbols are for a turbulent velocity of 10 km s^{-1}, large symbols for turbulent velocity of 20 km s^{-1}. | |
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Figure 2: Equivalent width predictions (in Å) for hydrogen lines are plotted for dwarfs (crosses), giants (circles), supergiants (squares) and lower surface gravity supergiants (triangles). Small symbols are for a turbulent velocity of 10 km s^{-1}, large symbols for a turbulent velocity of 20 km s^{-1}. | |
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Figure 3: Equivalent width predictions (in Å) for He II lines are plotted for dwarfs (crosses), giants (circles), supergiants (squares) and lower surface gravity supergiants (triangles). Small symbols are for a turbulent velocity of 10 km s^{-1}, large symbols for turbulent velocity of 20 km s^{-1}. | |
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Figure 4: Equivalent width predictions (in Å) for He I are plotted for dwarfs (crosses), giants (circles), supergiants (squares) and lower surface gravity supergiants (triangles). Small symbols are for a turbulent velocity of 10 km s^{-1}, large symbols for turbulent velocity of 20 km s^{-1}. | |
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Figure 5: The maximum and minimum EW predictions (in Å) are plotted for dwarf (solid lines), and supergiant (dotted lines) models. Models beyond the bi-stability jump are denoted by plusses. Observations from Hanson et al. (1996); Blum et al. (1997); Hanson et al. (1998); Zaal et al. (2001) and Lenorzer et al. (2002a) are plotted with crosses for dwarfs, circles for giants and squares for supergiants. Typical error on the observations is 0.5 Å. | |
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Figure 6: The correlation between optical and near-infrared He I/He II equivalent width ratios which may be used to calibrate spectral types. Circles denote EW predictions for a relatively high spectral resolution ( ); triangles give predictions for medium resolution ( ). The plus symbols give observed ratios. | |
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Figure 7: The predicted equivalent widths for dwarfs (denoted by crosses), giants (circles) and supergiants (squares) and lower surface gravity supergiants (triangles) are overplotted with observations from Lenorzer et al. (2002a), for which Q was derived from Lamers et al. (1999), Puls et al. (1996), and Kudritzki et al. (1999). Q is given in units of 10^{-20} yr^{-1} per per K^{2} per km s^{-1}. | |
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