BLIND SOURCE SEPARATION OF ASTRONOMICAL IMAGES

Danielle Nuzillard, Albert Bijaoui
Danielle.Nuzillard@univ­reims.fr, Bijaoui@obs­nice.fr

Celestial sources are studied by means of multispec­ tral analysis, for which a pixel value can be consid­ ered as a mixture of different sources. We show that the application of blind source separation (BSS) meth­ ods can display interesting features, which could help the astronomers to improve their description of celes­ tial sources. Experiments were done on Hubble Space Telescope (HST) images of the galaxy 3C120. Different ways were applied for the separation: tools based on the correlation between the shifted sources, and tools based on non­Gaussian probability density functions (PDF). Each obtained source set was quantified by the mutual information between the sources. Different algorithms give quite similar decompositions which mainly corre­ spond to real phenomena.