Spectral Resolution

Spectral resolution is crudely characterized by the FWHM (in pixels) of an unresolved spectral line.

Spectral Resolution (FWHM) Tables

Detector	Gratings
MAMA	G140L, G230L, G140M, G230M
MAMA	E140M, E230M
MAMA	E140H, E230H
CCD	G430L, G750L, G430M, G750M

For point sources, FWHM is relatively insensitive to aperture width, but spectral purity degrades with increasing aperture width.

Line Spread Functions (LSF) or instrumental profiles give the detailed distribution of light along the primary dispersion axis.

Turning off the FUV-MAMA repeller reduces LSF wings, but use of this available mode requires a strong scientific justification.