<title>Faint object spectrograph early performance</title>

Abstract

The Faint Object Spectrograph (FOS) instrument aboard the Hubble Space Telescope (HST) provides astronomers a moderate spectral resolution, low light level, analytical instrument sensitive throughout the wavelength region from below 120 nm to beyond 800 nm. The on-orbit performance of the HST + FOS instrument is described and illustrated with examples of initial scientific results.The severe spherical aberration resulting from the misfiguring of the HST primary mirror strongly impacts the combined HST + FOS performance. The effects of the spherical aberration upon isolated point sources and in complex fields such as the nuclei of galaxies are analyzed. Substantial effort has gone into studying possible means for eliminating the effects of spherical aberration. Concepts include using image enhancement software to extract maximum spatial and spectral information from the existing data as well as several options to repair or compensate the HST's optical performance. In particular, it may be possible to install corrective optics into the HST which will eliminate the spherical aberration for the FOS (and some of the other instruments). A brief description of the more promising ideas and calculations of the expected improvements in performance are provided.

Photometric and Spectroscopic Studies of the Intermediate -Polar Cataclysmic System DQ Her

“…Due to lack of IUE spectra for DQ Her, Hubble Space Telescope (HST-FOS) observations of DQ Her have been collected from the Hubble Space Telescope center (MAST) at site a . For an explanation of the FOS spectrographs see Kimble et al (1998); Woodgate et al [36]; Harms and Fitch [9]. The Hubbel Space Telescope data were analyzed using the standard IRAF software package for the reduction and analysis of spectrum.…”

Spectral characterization of HST calibration lamps: new Pt/Cr-Ne line catalogues and aging test

“…1 and Fastie & Mount 2 for details on these lamps. Since the lamp worked successfully throughout the entire 18 years lifetime (1978 -1996) of the IUE, similar devices were chosen for spectrographs onboard the Hubble Space Telescope (HST) -the Goddard High Resolution Spectrograph (GHRS), 3,4 the Faint Object Spectrograph (FOS), 5,6 the Space Telescope Imaging Spectrograph (STIS) 7,8 and the Cosmic Origins Spectrograph (COS). 9 See Macchetto's review 10 for a brief overview of HST's major scientific achievements.…”