| Abstract |
We have used the Wisconsin Hα Mapper facility to measure the [O I]
λ6300/Hα line intensity ratios for four O star H II
regions: S27 (observation coordinates l=6.3d,b=+23.6d), S252
(l=190.1d,b=+0.6d), S261 (l=194.1d,b=-1.9d), and S264
(l=195.1d,b=-12.0d). We find that the ratios range from 0.0015 to
0.0053. These results are roughly a factor of 10 lower than measured [O
I]/Hα ratios in directions that sample the warm ionized component
of the interstellar medium. This difference implies a significantly
lower hydrogen ionization ratio n(H+)/n(H0) or
higher electron temperature in the diffuse ionized gas compared with
that in the bright discrete O star H II regions. |