Periodic radio variability in NRAO 530:phase dispersion minimization analysis

摘要

A periodicity analysis of the radio light curves of the blazar NRAO 530 at 14.5,8.0,and 4.8 GHz is presented employing an improved phase dispersion minimization technique.The result,which shows two persistent periodic components of ～ 6 and ～ 10 yr at all three frequencies,is consistent with the results obtained with the Lomb-Scargle periodogram and weighted wavelet Z-transform algorithms.The reliability of the derived periodicities is confirmed by the Monte Carlo numerical simulations which show a high statistical confidence.(Quasi-)Periodic fluctuations of the radio luminosity of NRAO 530 might be associated with the oscillations of the accretion disk triggered by hydrodynamic instabilities of the accreted flow.