The IUE blaze function in the MG II region.

Abstract

To obtain reliable emission profiles of Mg II resonance lines from the IUE data it is absolutely necessary to perform a good ripple correction of the IUE net spectrum. An experimental blaze function (valid for the IUE orders from 88 to 79) has been derived as the ratio between the IUE data and those of the Copernicus satellite: in fact, the latter are not affected by any 'blaze efficiency' problem. The obtained blaze function was used to correct 39 IUE spectra of stars of different spectral types with very good results: the order edges now overlap very well in all the processed images. An attempt to find any possible trend of the derived blaze function with time or with signal level was fruitless.