Cosmic-abundance absorption dips in X1755-33.

Abstract

Results of spectral analysis for the source X1755-33 using the 1984 EXOSAT/ME data are presented, with spectral fitting made to the complete 18-h observation by dividing it into 314 consecutive 400-s timebins. It is found that spectral changes take place on time scales of this order and that analysis of longer sections of data can lead to errors. Good fits are obtained with a two-component model, indicating that the dips can be explained by energy-dependent absorption in material of cosmic abundance.