FUV Grating G160M

Description

The G160M grating samples wavelengths between about 1405 and 1775 Å. It offers higher resolution and effective area than the G140L grating, but less spectral coverage.

Special Considerations

The gap between segments A and B spans 18.1 Å. To fill this gap requires exposures separated by two central-wavelength settings.

Grating	Resolving Power R = λ/Δλ	Dispersion (mÅ pixel–1)	Plate Scale (milliarcsec pixel-1)		FP-POS Step (Å step-1)
			Disp. Axis	Cross-Disp. Axis
G160M	16,000 - 21,000	12.23	24.3	90	3.2

Figure 13.10: Wavelength Ranges for the G160M Grating

G160M Point-Source Sensitivity

Table 13.6: G160M Point-Source Sensitivity for PSA

Wavelength (Å)	Throughput	Sensitivity (counts pixel-1 sec-1 per erg cm-2 sec-1 Å-1)	Effective Area (cm2)
1400	4.024E-02	1.6E+12	1.82E+03
1450	3.488E-02	1.4E+12	1.58E+03
1500	2.616E-02	1.1E+12	1.18E+03
1550	2.078E-02	9.0E+11	9.40E+02
1600	1.588E-02	7.1E+11	7.18E+02
1650	1.216E-02	5.6E+11	5.50E+02
1700	9.991E-03	4.7E+11	4.52E+02
1750	8.343E-03	4.1E+11	3.77E+02

Figure 13.11: G160M Point-Source Sensitivity for PSA and BOA

G160M Signal-to-Noise Ratio

Figure 13.12: Point-Source Signal-to-Noise as a Function of STMAG for G160M at 1610 Å

The top axis displays constant Fλ values corresponding to the STMAG units (V+STMAGλ) on the bottom axis. Recall that STMAG = 0 is equivalent to Fλ = 3.63E-9 erg cm-2 s-1 Å-1. Colors refer to exposure times in seconds. The edge of the shaded area corresponds to the bright-object screening limit. Use of the PSA is assumed.