BL Lac天体Mkn 421射电流量变化周期特性

利用芬兰Metshovi射电望远镜22和37 GHz的观测数据,得到了Mkn 421从1986年1月到2005年1月的历史光变曲线.使用DCF方法进行周期分析,结果表明:(1)Mkn 421在射电22 GHz波段具有约(3.85±0.10)yr的周期,在射电37 GHz波段具有约(4.05±0.10)yr的周期.这两个周期值的平均值为3.95 yr,是Mkn 421的最小周期,Liu等人在光学波段发现的(23.1±1.1)yr的周期可能是这个周期叠加的结果;(2)用Mkn 421在射电22和37 GHz波段的准同时数据得到射电22~37 GHz波段的谱指数,谱指数和射电流量密度之间有较强的相关.

The characteristic periodicity analysis of the radio flux variability of BL Lac object Mkn 421

We have presented the radio light curve for BL Lac object Mkn 421 on the radio 22 and 37 GHz band by the Metshovi radio observatory＇s data from January 1986 to January 2005.The DCF method has been used to study the characteristic periodicity of Mkn 421,and the results shows that the light curve variability period value of Mkn 421 is（3.85±0.10） yr on 22GHz band,（4.05±0.10） yr on the 37 GHz band.This two variability period value’s mean value is 3.95 yr which is the smallest period value of Mkn 421 at present.The period value（23.1±1.1） yr got by Liu on the optical band should be overlied by this nearly four-year period value.Studied the quasi-periodic data of the radio 22GHz and 37 GHz band,the spectral index of the two band have been got,and the results shows that there is strong correlation between the spectral index and the radio flux density.