|Space Telescope Science Institute|
|Handbooks HTML Update Nov 2014|
G430L, used with the CCD, is a low resolution grating (R~500) with a relatively high throughput. The grating has only a single setting.This grating is designed for observations where high spectral resolution is not required, but efficient spectral coverage in the blue portion of the optical is desired.Notice, that by taking two observations, one with G750L and one with G430L, the full spectral region, from the NIR at 10000 Å through the optical at 3000 Å can be efficiently observed at an R~500.
Figure 13.10: Wavelength Ranges for the G430L Grating Settings
Point source sensitivity assumes full transmission (zero slit losses). Diffuse source sensitivity assumes a 0.1arcsecond wide slit. To convert point source sensitivities to diffuse source sensitivities multiply the point source values by the grating spatial (cross dispersion) plate scale in units of arcseconds per pixel and by the width of the desired slit in units of arcseconds.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/cm2/s/Å. The curves are labeled with exposure times in seconds