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Hubble Space Telescope
GHRS Instrument Science Report 063

GHRS Instrument Science Report 063

"Line Spread Functions and Resolution for GHRS-LSA Spectra with COSTAR"

Ronald L. Gilliland

Abstract excerpted from the report:

Deployment of the COSTAR mirrors for GHRS has successfully cancelled the
deleterious effects resulting from spherical aberration of the HST
primary mirror. Prior to COSTAR, the Large Science Aperture (LSA) line
spread function (LSF) was characterized by a Gaussian core nearly twice
as broad as that provided by the instrumental resolution limit with
extended non-Gaussian wings. After COSTAR the LSF for the LSA is only
20-30% broader in a Gaussian core than spectra from the SSA and the 
extended wings are absent.