Periodicity versus selection effects in the redshift distribution of QSOs

Abstract

Periodicities and selection effects in the redshift (z) distribution of QSOs have been debated for a long time in the literature. Here we show that peaks and troughs in the redshift distribution of three new samples, claimed to demonstrate the existence of a periodicity, can be interpreted in terms of known selection effects. This analysis confirms earlier findings that the presence of such selection effects seriously weakens any suggestion for periodicity of the form Δl n (1 + z) = constant.

Astrophysics in 2002

“…A similar sort of cell size continues to turn up in much less restrictive sorts of surveys (Tago et al 2002;Einasto et al 2002), and we suppose there must be something in it (besides voids inside the cell wells). It is much harder to develop enthusiasm for redshifts quantized in intervals of ln (1 ϩ z) p (Ryabinkov et al 2001;Roberts 2002), and we are in-0.089 clined to wish that Basu (2001) had chosen to publish in some more widely read journal. He concludes that the "0.089" effect in three recent samples arises from the numbers and strengths of the emission lines available for measurement and how they move through the V and B color bands, changing BϪV as they go.…”