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Cosmic Origins SpectrographInstrument Handbookfor Cycle 22 > Chapter 13: Spectroscopic Reference Material > FUV Grating G130M with CENWAVE=1222

FUV Grating G130M with CENWAVE=1222
Description
When used with a central wavelength of 1222 , grating G130M samples wavelengths between about 1065 and 1365 with a resolving power R > 10,000. Its sensitivity is comparable to that of other G130M modes and considerably higher than G140L. Preliminary measurements indicate that the resolving power of this mode is R > 13,000 at 1135 and R > 10,000 at 1340 ..
Special Considerations
A key advantage of this observing mode is that it places the Lyman-α airglow line in the gap between detector segments A and B, eliminating this source of damaging high-intensity flux.
Resolving
Power
R = λ/Δλ
Dispersion
(m pixel–1)
FP-POS
Step
( step-1)
Figure 13.5: Wavelength Ranges for the G130M/1222 Mode
G130M/1222 Point-Source Sensitivity
Table 13.4: G130M/1222 Point-Source Sensitivity for PSA
Sensitivity
(counts pixel-1 sec-1 per
erg cm-2 sec-1 -1)
Figure 13.6: G130M/1222 Point-Source Sensitivity for PSA
The sensitivity through the BOA is not shown, as its MgF2 filter is opaque at wavelengths λ < 1150 .
G130M/1222 Signal-to-Noise Ratio
Figure 13.7: Point-Source Signal-to-Noise as a Function of STMAG for G130M at 1135
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 with CENWAVE=1222

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