|COS Instrument Handbook for Cycle 25|
The G185M grating samples wavelengths between about 1700 and 2100 Å. The grating has 15 central wavelength settings.G185M spectra consist of three 35 Å stripes separated by two 64 Å gaps. To acquire a complete spectrum requires the use of six central-wavelength settings.
R = λ/Δλ
Figure 13.17: Wavelength Ranges for the G185M GratingTable 13.8: G185M Point-Source Sensitivity for PSA
(counts pixel-1 sec-1 pererg cm-2 sec-1 Å-1)
Figure 13.18: G185M Point-Source Sensitivity for PSA and BOAThe 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.