Space Telescope Imaging Spectrograph Instrument Handbook for Cycle 17

F25CN270-NUV-MAMA

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Description

The F25CN270 filter with the NUV-MAMA provides medium bandwidth imaging near the 2798 Å MgII feature.

Recommended Uses

Continuum filter for MgII imaging.

Special Considerations

There is a substantial redleak in this filter. Sources with a red underlying continuum may be difficult to observe. Users should be careful to take into account the underlying continuum in estimating whether the observation will fall within the bright object protection limits.

Pivot (Å)	FWHM (Å)	AB mag zero point	Speak	B	R80 (arcsec)	Flux in central pixel
2710.9	161.8	21.360	1.17e+14	202.3	0.17	14%

Figure 14.50: F25CN270 NUV-MAMA Integrated System Throughput and Redleak


 

Table 14.20: F25CN270 NUV-MAMA Sensitivity & Throughput

	Sensitivity	% Throughput
2575.	6.70E12	0.11
2600.	6.37E13	1.08
2625.	8.19E13	1.37
2650.	1.01E14	1.67
2675.	1.13E14	1.86
2700.	1.12E14	1.82
2725.	1.10E14	1.77
2750.	8.70E13	1.39
2775.	9.22E13	1.46
2800.	9.81E13	1.54
2825.	6.27E13	0.97
2850.	1.40E13	0.21

Figure 14.51: Point Source S/N vs. V+AB for the F25CN270 NUV-MAMA mode. Curves are labeled by required exposure time (sec).


 
Figure 14.52: Extended Source S/N vs. V+AB for the F25CN270 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 (sec).


 

Table 14.21: Radial Profile for F25CN270*

Radius			Fraction of Energy Encircled
Pixels	Arcsec	intensity
1	0.024	5.158e-02	0.240
1.5	0.037	2.953e-02	0.378
2	0.049	1.608e-02	0.504
3	0.073	5.260e-03	0.643
4	0.098	2.022e-03	0.708
5	0.122	1.215e-03	0.750
10	0.245	2.048e-04	0.854
15	0.367	9.848e-05	0.908
20	0.490	4.138e-05	0.942
25	0.613	1.817e-05	0.960
30	0.735	1.440e-05	0.974
40	0.980	4.656e-06	0.994

* See STIS ISR 2003-01.

Figure 14.53: Point Source Encircled Energy for F25CN270 NUV-MAMA


 
Figure 14.54: Point Source Intensity vs. Radius for F25CN270 NUV-MAMA