F25ND5 - FUV-MAMA

Description

The F25ND5 mode with the FUV-MAMA detector provides broad band imaging with an attenuation of 7 × 10-7. The R80 and central pixel flux are unmeasured but assumed to be approximately the same as produced by the F25QTZ filter.

Recommended Uses

Recommended for broad-band imaging of objects too bright by about a factor of 106 to meet FUV-MAMA BOP limits.

Special Considerations

At FUV wavelengths the attenuation is closer to a factor of 106 rather than the nominal 105, but the attenuation factor decreases at longer wavelengths, 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 (Å)

FWHM (Å)

AB mag zero point

Speak

Bλ

R80 (arcsec)

Flux in central pixel

1385.1

333.6

8.188

8.81e7

377.2

0.28

10%

Figure 14.74: F25ND5 FUV-MAMA Integrated System Throughput and Redleak



Table 14.29: Throughput and Sensitivity for F25ND5 FUV-MAMA

λ

Sensitivity

% Throughput

1150.

6.52E6

2.5E-7

1200.

5.34E7

2.0E-6

1250.

8.05E7

2.8E-6

1300.

7.87E7

2.7E-6

1350.

7.11E7

2.3E-6

1400.

6.22E7

2.0E-6

1450.

5.23E7

1.6E-6

1500.

4.36E7

1.3E-6

1550.

3.67E7

1.0E-6

1600.

2.95E7

8.1E-7

1650.

2.37E7

6.3E-7

1700.

1.66E7

4.3E-7

1750.

1.09E7

2.7E-7

1800.

6.65E6

1.6E-7

1850.

2.38E6

5.6E-8

Figure 14.75: Point Source S/N vs. V+ABν for the F25ND5 FUV-MAMA mode. Curves are labeled by required exposure time (seconds).


Figure 14.76: Extended Source S/N vs. V+ABν for the F25ND5 FUV-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).