Blind source separation and analysis of multispectral astronomical images

¹ Laboratoire d'Automatique et de Microélectronique, Université de Reims Champagne-Ardenne, Moulin de la Housse, BP. 1039, F-51687 Reims Cedex 2, France e-mail: Danielle.Nuzillard@univ-reims.fr
² Dpt. CERGA, UMR CNRS 6527, Observatoire de la Côte d'Azur, BP. 4229, F-06304 Nice Cedex 4, France e-mail: Bijaoui@obs-nice.fr

Send offprint request to: D. Nuzillard

Received: 26 May 2000
Accepted: 31 August 2000

Abstract

Celestial sources are studied by means of multispectral analysis, for which a pixel value can be considered as a mixture of different sources. We show that the application of blind source separation methods can display interesting features, which can help astronomers to improve their description of celestial sources. Experiments were carried out on Hubble Space Telescope images of the galaxy 3C 120. Different separation methods were applied, either based on the source correlation, or on non-Gaussian probability density functions. Each obtained source set was quantified by the mutual information between the sources. Different algorithms give quite similar decompositions which mainly correspond to real phenomena.