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Detection of [N II] 5755 Emission from Low Density Ionized Interstellar Gas

R. J. Reynolds·N. C. Sterling·L. M. Haffner·S. L. Tufte
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Abstract

The extremely faint, temperature sensitive ``auroral'' emission line [N II] 5755 has been detected from the low density ionized gas along the sight line toward l = 130.0, b = -7.5 using the Wisconsin H-Alpha Mapper (WHAM). The intensity of this emission line, relative to the red nebular line [N II] 6584, is found to be twice that observed in bright, classical H II regions surrounding O stars. This implies that the electron temperature of the ionized gas along this sight line is about 2000 K higher than the H II regions, and that the enhanced [N II] 6584/H-Alpha and [S II] 6716/H-Alpha intensity ratios in this low density gas are due at least in part to an elevated temperature.

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R. J. Reynolds, N. C. Sterling, L. M. Haffner, S. L. Tufte. 2001-01-26. Detection of [N II] 5755 Emission from Low Density Ionized Interstellar Gas. https://doi.org/10.1086/319119

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