In this paper,the time series analysis method CLEANest is employed to search for characteristic periodicities in the radio light curves of the blazar NRAO 530 at 4.8,8.0 and 14.5 GHz over a time baseline of three deca...In this paper,the time series analysis method CLEANest is employed to search for characteristic periodicities in the radio light curves of the blazar NRAO 530 at 4.8,8.0 and 14.5 GHz over a time baseline of three decades.Two prominent periodicities on time scales of ~6.3 and ~9.5 a are identified at all three frequencies,in agreement with previous results derived from different numerical techniques,confirming the multiplicity of the periodicities in NRAO 530.In addition to these two significant periods,there is also evidence of shorter-timescale periodicities of ~5.0,~4.2,~3.4 and ~2.8 a showing lower amplitude in the periodograms.The physical mechanisms responsible for the radio quasi-periodic oscillations and the multiplicity of the periods are discussed.展开更多
基金supported by the National Basic Research Program of China (Grant Nos.2009CB24900 and 2012CB821800)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDA04060700)+1 种基金the National Natural Science Foundation of China (Grant No.61261017)The University of Michigan Radio Astronomy Observatory is supported by the funds from NSF,NASA,and the University of Michigan
文摘In this paper,the time series analysis method CLEANest is employed to search for characteristic periodicities in the radio light curves of the blazar NRAO 530 at 4.8,8.0 and 14.5 GHz over a time baseline of three decades.Two prominent periodicities on time scales of ~6.3 and ~9.5 a are identified at all three frequencies,in agreement with previous results derived from different numerical techniques,confirming the multiplicity of the periodicities in NRAO 530.In addition to these two significant periods,there is also evidence of shorter-timescale periodicities of ~5.0,~4.2,~3.4 and ~2.8 a showing lower amplitude in the periodograms.The physical mechanisms responsible for the radio quasi-periodic oscillations and the multiplicity of the periods are discussed.