52X2 Aperture

Description

This slit is supported for all first-order gratings and is available-but-unsupported for the echelle gratings. It is a good slit for spectrophotometric observations of point sources. The small dip in throughput seen at 2000 Å is likely due to uncertainties in the numerical calculation, and will not affect the absolute flux calibration.

Special Considerations

Observations using this slit do not need to be preceded by a PEAKUP. Be aware of effects of OTA scatter on the line profiles when observing point sources in wide slits (see Section 13.7). Targets not centered on the slit along the spatial direction can experience significant shifts in wavelength. Use of this long slit with an echelle grating will cause order overlap problems (particularly for the most closely spaced orders; see Section 12.2), but for point sources the order separation may be adequate for many science programs.


Table 13.22: 52X2 Throughputs.

λ

% Throughput

1200

96.6

1800

98.1

2400

98.5

3000

98.7

3600

98.7

4200

98.8

4800

98.8

5400

98.8

6000

98.8

6600

98.8

7200

98.8

7800

98.8

8400

98.9


Projected Length (arcsec)


 

Aperture

CCD

MAMA (M-modes)

MAMA (L-modes)

Width (arcsec)

52X2

52.0

28.0

25.0

2.0

Figure 13.69: 52X2 Aperture Throughput as a Function of Wavelength.