Sunyaev-Zel'dovich effect and morphology of galaxy clusters

摘要

We investigate the influence of the finite extension and the aspherical geometry of a galaxy cluster on the estimate of the Hubble constant through the Sunyaev-Zel'dovich (SZ) effect. An analysis of a recent Chandra image of the galaxy cluster RBS797 indicates a strong ellipticity and thus a pronounced aspherical geometry. We estimate the total mass of RBS797 assuming spherical or ellipsoidal geometry and show that in the latter case the mass is about 10-17% less than the one inferred for a spherical shape.