|Space Telescope Science Institute|
|COS Instrument Handbook|
The G130M grating samples wavelengths between about 900 and 1450 Å. (Its use at shorter wavelengths is discussed below.) It offers higher resolution and effective area than the G140L grating, but less spectral coverage.The gap between segments A and B spans 14.3 Å. To fill this gap requires exposures separated by two central-wavelength settings.
R = λ/Δλ
16,000 - 21,0001
Figure 13.2: Wavelength Ranges for the G130M GratingTable 13.3: G130M Point-Source Sensitivity for PSA
(counts pixel-1 sec-1 pererg cm-2 sec-1 Å-1)
Effective Area (cm2) Figure 13.3: G130M Point-Source Sensitivity for PSA and BOAThe throughput of the BOA is poorly characterized below 1200 Å and close to zero below 1150 Å.Figure 13.4: Point-Source Signal-to-Noise as a Function of STMAG for G130M at 1310 ÅThe 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.