The frequency 10 Hz in the distribution of radiopulsar periods.

A special statistical procedure, based on computation of the so-called "commensurability spectrum", being applied to the distribution of periods of 330 pulsars revealed the dominant frequency ν₀ = 10.05±0.07 Hz (period 0.0995±0.0007 s) of a quasiperiodic modulation of the distribution. This modulation means the presence of a statistically significant, at about 3.3 to 4.1-sigma confidence level, deficit of a number of PSR with frequencies ν ≈ ν₀/n, where n is integer. The effect appears to be strongly pronounced for PSR with periods from 0.4 to about 1.6 s and can not be ascribed to some unknown observational selection effect.