Radio Variability Properties of a Sample of 168 Radio Sources: Periodicity Analysis

In this work, using the data base at the University of Michigan Radio Astronomy Observatory (UMRAO) at 8 GHz, we investigated the possible periodicity in the radio light curves using Jurkevich analysis method. The results show that the radio sources display a possibly physically significant periodicity in a range of 0.08 to 14.5 years. Besides, the radio spectral indexes are also calculated, the results show that the averaged radio spectral index is α4.814.5 = −0.15 (fν∝να) for flat spectrum radio quasars (FSRQs) and α4.814.5=0.01 for BL Lacertae objects. Some discussions are included.