Space Telescope Science Institute
STIS Instrument Handbook
help@stsci.edu
Table of Contents Previous Next Index Print


Space Telescope Imaging Spectrograph Instrument Handbook for Cycle 22 > Chapter 14: ImagingReference Material > F25ND5—NUV-MAMA

F25ND5—NUV-MAMA
Description
The F25ND5 mode with the NUV-MAMA provides broad band imaging with an attenuation of 5 10-6. The field of view is 25 25 arcsec. The value of R80 and the central pixel flux are unmeasured but assumed to be approximately the same as produced by the F25QTZ filter.
Recommended Uses
Recommended for broad-band NUV imaging of objects too bright by 2 105 for clear mode.
Special Considerations
The throughput of the ND5 filter and NUV-MAMA combination relative to the unfiltered NUV-MAMA varies strongly as a function of wavelength. At wavelengths between 3000 and 5000 the attenuation factor is close to 5 106. At shorter wavelengths the relative throughput can be a factor of ten or more smaller, while at longer wavelengths it is considerably larger, so special care should be taken for red sources. To make an accurate prediction of the expected count rate, observers should use a good approximation of the source spectrum as input for the STIS ETC.
Pivot λ ()
Speak
Bλ
R80 (arcsec)
Figure 14.31: F25ND5 NUV-MAMA Integrated System Throughput and Redleak
Table 14.13: Throughput and Sensitivity for F25ND5 NUV-MAMA
Figure 14.32: Point Source S/N vs. V+ABν for the F25ND5 NUV-MAMA mode. Top curves are for DARKTIME. Bottom curves are for average sky. Top curves are for DARKTIME. Bottom curves are for average sky. Curves are labeled by required exposure time (seconds).
Figure 14.33: Extended Source S/N vs. V+ABν for the F25ND5 NUV-MAMA mode. Top curves are for an area of 0.2 arcsec2; bottom curves are for 1 arcsec2. Average sky assumed. Curves are labeled by required exposure time (seconds).

Space Telescope Imaging Spectrograph Instrument Handbook for Cycle 22 > Chapter 14: ImagingReference Material > F25ND5—NUV-MAMA

Table of Contents Previous Next Index Print