Hubble Space Telescope Primer for Cycle 17

4.6 Space Telescope Imaging Spectrograph (STIS)

STIS has been unavailable since August 2004. However, a repair to STIS may be attempted during SM4 to recover the instrument for science operations in Cycle 17. Observers should consult the STIS Instrument Handbook and STIS Web Page for current information on performance and availability.

The Space Telescope Imaging Spectrograph was installed in February 1997, and provides ultraviolet and optical spectroscopy and imaging through three channels. The STIS can be used to obtain spatially resolved, long-slit (or slitless) spectroscopy over the 115 - 1030 nm wavelength range at spectral resolutions of R ~ 500 to 17,500, and echelle spectroscopy over the 115 - 310 nm wavelength range at spectral resolutions of R ~ 30,000 and 114,000, covering broad spectral ranges of ~ 80 nm and 20 nm, respectively. STIS can also be used for optical and solar-blind ultraviolet imaging. Three detectors, each with a 1024 x 1024 pixel format, support spectroscopy and imaging as follows.

The far ultraviolet channel, the STIS/FUV-MAMA, uses a solar-blind, CsI, Multi-Anode Microchannel detector Array (MAMA), with a field-of-view 25" x 25", a plate scale of 0.025 arcsec/pixel, and covers the wavelength region from 115 - 170 nm.

The near ultraviolet channel, the STIS/NUV-MAMA, uses a Cs₂Te MAMA detector with the same FOV and plate scale, and covers the 160 - 310 nm wavelength region.

For the 165 - 1100 nm optical wavelength region, the STIS/CCD detector is a thinned and backside-illuminated SITe CCD with a near-ultraviolet optimized coating. The field-of-view is 52" x 52" and the plate scale is 0.05 arcsec/pixel.

The MAMA detectors can be used in ACCUM or TIME-TAG modes, with the latter supporting time-resolutions down to 125 µsec, and the CCD is able to be cycled in ~ 20 seconds when using small subarrays. The CCD and the MAMAs also provide coronagraphic spectroscopy in the visible and ultraviolet. Coronagraphic CCD imaging is also available (see next section). Each of the STIS detectors can also be used for imaging observations, although only limited filter choices are available.