SIMBAD references

We have used the Wisconsin Hα Mapper (WHAM) facility to measure the interstellar Hα emission toward the high Galactic latitude O star HD 93521 (l=183°.1, b=+62°.2). Three emission components were detected along this line of sight. These components have radial velocities of -10, -51, and -90 km.s^–1 with respect to the local standard of rest (LSR) and have Hα intensities of 0.20, 0.15, and 0.023 R, respectively, corresponding to emission measures of 0.55, 0.42, and 0.06 cm^–6 pc. We have also measured the Hα emission toward the direction l=148°.5, b=+53°.0, which lies in the region of exceptionally low H I column density known as the Lockman Window. An emission component is detected in this direction at -1 km.s^–1 (LSR), with an intensity of 0.20 R (0.55 cm^–6 pc). In addition, we studied the direction l=163°.5, b=+53°.5. No Galactic emission was detected along this line of sight, and upper limits on the possible intensity of Galactic emission toward this direction are 0.11 R at the LSR and 0.06 R at -50 km.s^–1. As part of the process of separating the interstellar from the terrestrial emission, we also detected and characterized 12 faint (∼0.03-0.15 R), unidentified atmospheric lines present in WHAM Hα spectra. Finally, we have used WHAM to obtain [O I] λ6300 spectra along the line of sight toward HD 93521. We do not conclusively detect interstellar [O I] emission toward the star, but place an upper limit of 0.060 R on the [O I] intensity of the intermediate-velocity (-51 km.s^–1) component. If the temperature of the gas is 10,000 K, this limit implies that, within the Hα-emitting region, the hydrogen ionization fraction n(H⁺)/n(H_ total_)>0.6.