F25SRF2 - NUV-MAMA, Longpass

Description

The F25SRF2 filter with the NUV-MAMA provides high-throughput broad-band NUV imaging with better rejection of geocoronal emission than the F25MAMA but worse than the F25QTZ mode. It provides the same field of view and high spatial resolution.

Recommended Uses

This filter has slightly higher throughput than F25QTZ, but lets in geocoronal O I 1302 Å triplet. In most cases the sky background will still be lower than the detector background.

Special Considerations

Sky background on the day side of the orbit contains a significant contributions from [OII] air glow emission at 2471 Å and O I 1302 Å triplet air glow. In high-background conditions, the sky background can dominate the detector background. In average day-side observing conditions the background from the sky is approximately half of the background coming from the detector dark current. Also, the background through F25SRF2 will be about 10% higher than through F25QTZ. Observers can limit the background by using the DARKTIME special requirement.

Pivot λ (Å)

FWHM (Å)

AB mag zero point

Speak

Bλ

R80 (arcsec)

Flux in central pixel

2302.7

1138.4

23.834

1.47e+14

1129.8

0.32

8%



Figure 14.41: F25SRF2 NUV-MAMA Integrated System Throughput and Redleak




Table 14.17: F25SRF2 NUV-MAMA Sensitivity & Throughput

λ

Sensitivity

% Throughput

1300.

8.93E12

0.30

1400.

2.27E13

0.71

1500.

2.96E13

0.87

1600.

3.16E13

0.87

1700.

3.37E13

0.87

1800.

4.23E13

1.03

1900.

5.73E13

1.32

2000.

7.90E13

1.73

2100.

1.02E14

2.12

2200.

1.21E14

2.42

2300.

1.340E14

2.56

2400.

1.40E14

2.56

2500.

1.44E14

2.53

2600.

1.47E14

2.48

2700.

1.44E14

2.34

2800.

1.38E14

2.16

2900.

1.13E14

1.72

3000.

8.74E13

1.28

3100.

4.33E13

0.61

3200.

1.93E13

0.27



Figure 14.42: Point Source S/N vs. AB magnitude in the V-band for the F25SRF2 NUV-MAMA mode. Top curves are for DARKTIME. Bottom curves are for average sky. Curves are labeled by required exposure time (sec.).




Figure 14.43: Extended Source S/N vs. AB magnitude in the V-band for the F25SRF2 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).