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A&A Supplement series, Vol. 127, Mars I 1998, 409-416

Received January 24; accepted July 11, 1997

Wavelength calibration at moderately high resolutiongif

J.-P. De Cuyper and H. Hensberge

Send offprint request: J.-P. De Cuyper,
Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussel, Belgium


Th-Ar lamps are commonly used as wavelength calibration units at moderately high spectral resolutions because of the richness of the Th spectrum in the visual. The inclusion of blended lines whose position is assumed to coincide with the laboratory wavelength of the principal component is shown to result in a calibration precision significantly worse than the intrinsic random noise limit. In order to avoid this degradation of the calibration, we present resolution-dependent Th-Ar wavelengths in the region 277 to tex2html_wrap_inline1060 for use at pixel-scales between tex2html_wrap_inline1062 and tex2html_wrap_inline1064.

keywords: methods: data analysis; techniques: spectroscopic

Copyright by the European Southern Observatory (ESO)