类星体3C273的多波段光变周期分析

Analysis of Multi-Wavelength Variation Periods of the Quasar 3C273

从文献中收集了类星体3C273射电、毫米、红外、光学、紫外和高能波段1963年至2006年的观测数据,获得各波段的长期光变曲线。用Jurkevich方法和离散相关函数(Discrete Correlation Function,DCF)方法分别研究了多波段的光变周期。研究结果表明:(1)3C273在所研究波段内的辐射流量都表现出周期性变化的特征;(2)用Jurkevich方法和离散相关函数方法分析得到的多波段变化周期的结果非常一致;(3)3C273在射电和毫米波段可能存在8.0年左右的固有周期成分,在红外、光学和紫外波段可能存在2.0年和11.0年左右的固有周期成分,在高能波段可能存在1.0年左右的固有周期成分。简要探讨了引起3C273各波段周期光变的可能原因,研究结果表明用激波加速模型(shock-in-jet)能较好地解释引起3C273多波段光变的原因。

In this paper we compile some photometric data of quasar 3C273 in radio, millimeter, infrared, optical, ultraviolet, and high-energy bands from 1963 to 2006 taken from literature. We obtain longterm light curves of these data. Using Jurkevich＇s method and the Discrete Correlation Function （DCF） method, we analyze the multi-wavelength variation periods of 3C273. Our results indicate that （1） there is evidence for certain quasi-periodic activities in all studied wavelengths of 3 C273, （2） the results of periods from Jurkevich＇ s method are almost as same as those from the DCF method, and （3） there are possible four intrinsic periodic components for 3C273 in all the wavelengths. There is an 8.0 year period for the radio and millimeter bands; for the infrared, optical, and ultraviolet bands, there are a 2.0 year and an 11.0 year periods ; and a 1.0 year period exists for the high-energy band. We briefly discuss possible mechanisms of the periodic variabilities of 3C273. Though many models have been proposed to explain periodic variations of quasars, including the binary black-hole model, slim-disk model, and change of accretion rate, our study indicates that the shock-in-jet model may be the best explanation for the periodic variabilities in 3C273.