Fiberoptically Multiplexed Medium Resolution Spectroscopy from the WIYN Telescope, Singlet D Neutral Oxygen, NH2, and H2O+

Abstract

The WIYN 3.5-meter telescope and its Multi-Object Spectrograph (MOS) have been used to obtain simultaneous spectra at many points in the coma of Comet Hale-Bopp. Between 1996 October and 1997 April in excess of 7500 individual spectra were obtained, typically 96 at a time. On six nights the “Hydra” fiber positioner was used to sample a ring pattern of points about the nucleus with a minimum spacing of 40 arc seconds and a maximum radius of 22.5 arc minutes. On four nights a new “Densepak” fiber cable was used. In this configuration a 7 × 13 rectangular pattern of 91, 3 arc second fibers on 4 arc second centers was used. In most cases the bench spectrograph was used in the echelle mode with an interference filter to isolate a single order. The wavelength range from 6100 A to 6400 A was recorded with resolution of approximately 15,000. This spectral region contains the emission features of [OI], C2, NH2and H2O+. From this mass of data we are beginning to extract the radial, azimuthal and temporal variations of many different spectral features. The radial profiles of [O I] λ6300 A and NH2 are reasonably well representable by the Haser model formalism, that of H2O+ is not.