Blazar天体3C 66A光学波段准周期光变分析

研究了Blazar天体3C 66A光学波段的准周期光变行为.收集了3C 66A光学V波段将近18 yr (2003—2021年)的测光数据,观测数据主要来源是:上海天文台(ShAO)、 AAVSO (The American Association of Variable Star Observers)数据库、Steward天文台.使用了Jurkevich和Lomb-Scargle两种方法分析了光变数据.Jurkevich方法得到了(850±90) d (～2.3 yr)和(1150±140) d (～3.2 yr)的光变周期,而Lomb-Scargle方法在充分考虑了“红噪声”效应之后同样得到了(869±70) d和(1111±90) d的光变周期,它们的置信水平分别为>99%和> 95%.通过与之前的研究结果比较,发现～2.3 yr的光变周期在3C 66A的历史光变数据中是一个稳定的周期,而～3.2 yr的周期则是不稳定的.

Analysis of Quasi-periodic Variability in the Optical Light Curve of Blazar 3C 66A

We searched the quasi-periodic variability in the light curve of blazar 3C 66A in the optical V band. The data used in this paper are from Shanghai Astronomical Observatory (ShAO), AAVSO (The American Association of Variable Star Observers) and Steward Observatory respectively, with a total coverage of sim18 years (from 2003 to 2021). Two methods were employed to search for the possible quasi-periodic variability in the resulting optical light curve of the source. The Jurkevich method yielded two possible periods of (850 pm 90)d (~2.3yr) and (1150±140)d (~3.2yr). While the Lomb-Scargle Periodogram, with the red noise considered, yielded two possible periods of (869±70)d and (1111±90)d, which are consistent with the results of the Jurkevich method. The significance level of the two periods calculated using the PSRESP (power spectra response) method are >99% and >95% for the two possible periods, respectively. We compared our results with previous researches and found that the period around 2.3 yr is stable in the historical light curve of 3C 66A, while the later one is more likely a transient phenomenon which is only present in the high state of the source.