The distribution of redshifts in new samples of quasi-stellar objects

Two new samples of QSOs have been constructed from recent surveys to test the hypothesis that the redshift distribution of bright QSOs is periodic in log (1 + z). The first of these comprises 57 different redshifts among all known close pairs or multiple QSOs with image separations less than or equal to 10 ", and the second consists of 39 QSOs selected through their X-ray emission and their proximity to bright, comparatively nearby active galaxies. The redshift distributions of the samples are found to exhibit distinct peaks with a periodic separation of similar to0.089 in log (1 + z) identical to that claimed in earlier samples, but now extended out to higher redshift peaks z = 2.63, 3.45, and 4.47, predicted by the formula but never seen before. The periodicity is also seen in a third sample, the 78 QSOs of the 3C and 3CR catalogs. It is present in these three data sets at a high overall significance level (similar to 10(-5)) and appears not to be explicable by spectroscopic or similar selection effects. Possible interpretations are briefly discussed.