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Session 3 - Source Surveys, Galaxy Surveys, Distance Scale I.
Display session, Wednesday, January 07
Exhibit Hall,

[3.10] Galaxy redshift from NICMOS Grism Parallel Images

E. M. Malumuth (Hughes STX/GSFC), H. Teplitz, J. P. Gardner (NOAO/GSFC), S. R. Heap (NASA/GSFC)

The Space Telescope Science Institute (STScI) began a program in June of 1997 of obtaining data with STIS and NICMOS in parallel with other HST observations. To date, the NICMOS program has been weighted toward J, H, and K band images with the NIC 2 camera in focus. However, for a short period the NIC 3 camera was in its best focus and ``in focus'' G141 grism spectral images were obtained. While a more crafted program remains for the future, the data obtained thus far are impressive.

We examine the NICMOS G141 grism spectra obtained (using the NIC 3 camera) between July 21 and Aug 4, 1997. During which the NICMOS internal focus was set as close to the optimal NIC 3 focus as it could be. At this focus, stars in F160W images have a FWHM \sim1.2 pixels (0\farcs24). These data range in exposure time from 2,048 sec to 14,336 sec for the grism images and 512 sec to 4,608 sec for the corresponding F160W images of the field. These images show a number of stars and galaxies. We show spectral images, the corresponding F160W images, and extracted spectra (with R \sim180) for galaxies covering a range of brightness and evaluate how well redshifts for faint (and presumably distant) galaxies can be determine from these data.

Program listing for Wednesday