Space Telescope Science Institute  F25NDQ - NUV-MAMA F25SRF2-NUV-MAMA, Longpass

F25QTZ-NUV-MAMA, Longpass


Description

The F25QTZ filter with the NUV-MAMA provides high-throughput broad-band near-UV imaging with better rejection of geocoronal emission than the F25MAMA or F25SRF2 modes, the same field of view, and the same high spatial resolution.

Recommended Uses

Recommended for broad-band near-UV imaging of faint targets.

Special Considerations

Sky background on the day side of the orbit contains a significant contribution from O II air glow emission at 2470 Å. In high-background conditions, the sky background can dominate the detector background. In average day-side observing conditions about half the background will be from the sky and half from detector dark current. Observers can limit the background (with some cost to the total amount of observing time per orbit) by using the DARKTIME special requirement

.
Pivot (Å)
FWHM (Å)
AB mag zeropoint
Speak
B
R80 (arcsec)
Flux in central pixel
2364.8
995.1
23.781
1.54e+14
1089.1
0.32
8%

Figure 14.35: F25QTZ NUV-MAMA Integrated System Throughput and Redleak

 

Table 14.15: Throughput and Sensitivity for F25QTZ NUV-MAMA
l
Sensitivity
Throughput %
1500.
2.01E13
0.59
1600.
2.63E13
0.72
1700.
3.08E13
0.79
1800.
3.91E13
0.95
1900.
5.48E13
1.27
2000.
8.10E13
1.78
2100.
1.08E14
2.26
2200.
1.29E14
2.57
2300.
1.42E14
2.71
2400.
1.51E14
2.76
2500.
1.53E14
2.69
2600.
1.52E14
2.56
2700.
1.48E14
2.40
2800.
1.41E14
2.21
2900.
1.17E14
1.77
3000.
8.85E13
1.30
Figure 14.36: Point Source S/N vs. V+AB for the F25QTZ NUV-MAMA mode. Top curves are for DARKTIME. Bottom curves are for average sky.

 
Figure 14.37: Extended Source S/N vs. V+AB for the F25QTZ NUV-MAMA mode. Top curves are for an area of 0.2 arcsec2; bottom curves are for 1 arcsec2. Average sky assumed.

 

Table 14.16: Radial Profile for F25QTZ
Radius

Fraction of Energy Encircled
Pixel
Arcsec
Intensity
1
0.024
6.046e-02
0.210
2
0.037
4.292e-02
0.328
2
0.049
2.825e-02
0.440
3
0.073
1.036e-02
0.591
4
0.098
4.085e-03
0.667
5
0.122
1.839e-03
0.718
10
0.245
2.099e-04
0.820
15
0.367
9.929e-05
0.874
20
0.490
4.775e-05
0.911
25
0.613
2.706e-05
0.934
30
0.735
1.876e-05
0.953
40
0.980
8.441e-06
0.983
Figure 14.38: Point Source PSF for F25QTZNUV-MAMA, 7."5 square (at pixel 606,649, log scaled). Note PSF ghost ~45 pixels left of peak pixel and a few 10-3 of the peak
.

 
Figure 14.39: Point Source Encircled Energy for F25QTZ NUV-MAMA

 
Figure 14.40: Point Source Intensity vs. Radius for F25QTZ NUV-MAMA

 

F25NDQ - NUV-MAMA F25SRF2-NUV-MAMA, Longpass
Space Telescope Science Institute
http://www.stsci.edu
Voice: (410) 338-1082
help@stsci.edu