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Space Telescope Imaging Spectrograph Instrument Handbook for Cycle 22 > Chapter 13: Spectroscopic Reference Material > First-Order Grating G430L

First-Order Grating G430L
Description
G430L, used with the CCD, is a low resolution grating (R~500) with a relatively high throughput. The grating has only a single setting.
Recommended Uses
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.
Special Considerations
Notice, that by taking two observations, one with G750L and one with G430L, the full spectral region, from the NIR at 10000 through the optical at 3000 can be efficiently observed at an R~500.
 
Figure 13.10: Wavelength Ranges for the G430L Grating Settings
G430L Sensitivities
Table 13.5: G430L Sensitivities & Throughputs for a Point Source
Figure 13.11: G430L Point Source (left axis), and Diffuse Source (right axis) Sensitivities.
Note
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.
G430L Signal-to-Noise
Note:
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/. The curves are labeled with exposure times in seconds
 
Figure 13.12: Diffuse Source Signal-to-Noise as a Function of STMAG for G430L
Figure 13.13: Point Source Signal-to-Noise as a Function of STMAG for G430L

Space Telescope Imaging Spectrograph Instrument Handbook for Cycle 22 > Chapter 13: Spectroscopic Reference Material > First-Order Grating G430L

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