Supported Long Slits for First Order Gratings
Detectors record 25, 28, or 52 arcsec of spatial information. Various slit widths trade spectral purity against photometric throughput.
|52X0.05||yes||21-51%||2 pixel spectral resolution when used with a MAMA detector|
|52X0.1||yes||33-75%||2 pixel spectral resolution when used with the CCD|
|52X0.2||no||40-87%||Good compromise between photometric throughput and spectral purity|
|52X0.5||no||49-93%||Good spectrophotometry for point sources, but spectral purity is degraded significantly|
|52X2||no||57-99%||Best spectrophotometry for point sources, but wings of PSF compromise spectral purity|
|52X0.2F1||no||42-87%||Nomenclature used to request placement of source behind a 0.5x0.2 arcsec occulting bar|
To mitigate CTI degradation effects, pseudo-apertures have been defined with "E1" suffixes.
Supported Apertures for Echelle Gratings
Generally short enough to prevent order overlap. Various aperture widths trade resolution against photometric throughput.
|0.2X0.06||yes||23-59%||2 pixel spectral resolution for E140M and E230M gratings|
|0.2X0.09||yes||27-69%||2 pixel spectral resolution for E140H and E230H gratings|
|0.2X0.2||no||34-83%||Good compromise between photometric throughput and spectral purity. Photometric reference aperture.|
|6X0.2||no||50-85%||Use to map extended sources with isolated emission lines. Severe order overlap.|
|0.1X0.03||2 stage||13-36%||Smallest STIS aperture. Best spectral resolution.|
|0.2X0.06FP||yes||25-64%||Can reduce the impact of fixed pattern noise|
|0.2X0.2FP||no||34-83%||Can reduce the impact of fixed pattern noise|
|0.2X0.05ND||yes||0.13-0.63%||Use to observe sources too bright for standard apertures|
|0.3X0.05ND||yes||0.02-0.07%||Use to observe sources too bright for standard apertures|
All supported combinations of aperture, optical element, and observing mode appear in Table 10.4 of the Phase 2 Proposal Instructions.
Only data obtained with supported apertures will be fully calibrated in the archive. Use of other available apertures must be justified.