Available formats: HTML | PDF | (gzipped) PostScript
Determining the reality of X-ray filaments
Received 29 December 1999 / Accepted 11 April 2000
A number of authors have reported filaments connecting bright structures in high-resolution X-ray images, and in some cases these have been taken as evidence for a physical connection between the structures, which might be thought to provide support for a model with non-cosmological redshifts. In this Paper I point out two problems which are inherent in the interpretation of smoothed photon-limited data of this kind, and develop some simple techniques for the assessment of the reality of X-ray filaments, which can be applied to either simply smoothed or adaptively smoothed data. To illustrate the usefulness of these techniques, I apply them to archival ROSAT observations of galaxies and quasars previously analysed by others. I show that several reported filamentary structures connecting X-ray sources are not in fact significantly detected.
Key words: methods: statistical X-rays: galaxies galaxies: Seyfert galaxies: quasars: general galaxies: starburst
© European Southern Observatory (ESO) 2000
Online publication: June 5, 2000