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Cosmic Origins SpectrographInstrument Handbookfor Cycle 22 > Chapter 13: Spectroscopic Reference Material > FUV Grating G130M

FUV Grating G130M
Description
The G130M grating samples wavelengths between about 900 and 1450 . (Its use at shorter wavelengths is discussed below.) 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 14.3 . To fill this gap requires exposures separated by two central-wavelength settings.
Resolving
Power
R = λ/Δλ
Dispersion
(m pixel–1)
FP-POS
Step
( step-1)
16,000 - 21,0001
1
See below for the 1055, 1096, and 1222 settings, which have R < 13,000.

Figure 13.2: Wavelength Ranges for the G130M Grating
G130M Point-Source Sensitivity
Table 13.3: G130M Point-Source Sensitivity for PSA
Sensitivity
(counts pixel-1 sec-1 per
erg cm-2 sec-1 -1)
Figure 13.3: G130M Point-Source Sensitivity for PSA and BOA
The throughput of the BOA is poorly characterized below 1200 and close to zero below 1150 .
G130M Signal-to-Noise Ratio
Figure 13.4: Point-Source Signal-to-Noise as a Function of STMAG for G130M at 1310
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 -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.

Cosmic Origins SpectrographInstrument Handbookfor Cycle 22 > Chapter 13: Spectroscopic Reference Material > FUV Grating G130M

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