[Previous] | [Session 15] | [Next]
S. Kern, D. McCarthy, H. Campins, R.H. Brown, M. Rieke (U. Arizona), S. Stolovy (CalTech)
Grism spectra of eleven Centaur and Trans-Neptunian Objects were obtained during the NICMOS/HST focus campaign in June 1998. These spectra span the 1-2.5 micron wavelength range which is especially sensitive to absorption features of likely surface frosts and which covers the telluric absorption at 2.0 microns. The visual magnitudes of these objects range from 16.5 (Chiron) to 22.8 (1997 CQ29). The resulting spectral resolution varies from 10-200 depending on the amount of binning necessary to obtain high signal-to-noise. Chiron exhibits a previously unobserved absorption feature at 2.0 microns, tentatively attributed to water ice. Spectra are also presented for 1997 CU26, Pholus, 1995 GO, 1996 TL66, and 1993 SC. Unexpected problems with intra-pixel sensitivity variations and flat-fielding have complicated the extraction of these calibrated spectra. To overcome these problems, new image processing techniques have been developed to extend the capabilities of the standard "NICMOSlook" reduction software.