Photometry

 Recent studies (e.g., [Veilleux et al. 1994]) have shown that Fabry-Perot data can be flux calibrated to an accuracy equal to that of CCD imagery and longslit spectroscopy. Rather than scaling to an externally calibrated data set, we have applied a primary calibration, employing standard star observations directly. Since this Fabry-Perot flux calibration procedure is described in more detail elsewhere (e.g., [Bland-Hawthorn et al. 1997]), we outline only the salient points below.

The star $\varepsilon$ Orionis was used to calibrate the H$\alpha$+[NII] observations; $\alpha$ Lyrae and $\eta$ Hydrae were used for the [OIII] observations. After cosmetic cleaning and applying the whitelight correction described above, the counts in each stellar image were summed, and then scaled by the telescope aperture size and exposure time. To obtain pixel values in units of counts cm^-2 sec^-1 Å^-1 we must then divide by the effective spectral bandpass of the etalon at each pixel. We emphasize that this value is not necessarily the same as either the spectral sampling of the cube or the etalon resolution. Rather, it is a measure of the amount of flux transmitted at a given wavelength for a sequence of etalon spacings; it depends primarily on the finesse (N_R) of the etalon. This ``effective bandpass'' was calculated by summing the flux under a synthetic monochromatic spectrum spanning an entire order of the appropriate theoretical Airy function and dividing by the peak value of the Airy function. We derived an effective bandpass of 3.0Å for our data sets. The scaled values of observed stellar counts were then compared with published flux values ([Hayes 1970]; [Hayes & Latham 1975]), corrected for atmospheric extinction. Each pixel in the final spectra has units of ergs cm^-2 sec^-1 pixel^-1 frame^-1, yielding total fluxes from the line fits in units of ergs cm^-2 sec^-1 pixel^-1. The final estimated systematic error in the flux calibration was $\sim$7.5%.