用随机过程方法研究耀变体4C 01.02的射电和γ射线光变特征时标  

Studying Radio and γ-ray Variability Characteristic Timescales of the Blazar 4C 01.02 with Stochastic Process Method

作　　者：张偲恒 闫大海 曾雨航 王建成[1] ZHANG Si-heng;YAN Da-hai;ZENG Yu-hang;WANG Jian-cheng(Key Laboratory for the Structure and Evolution of Celestial Objects,Yunnan Observatories,Chinese Academy of Sciences,Kunming 650011,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院云南天文台天体结构与演化重点实验室,昆明650011 [2]中国科学院大学,北京100049

出　　处：《天文学进展》2022年第4期590-597,共8页Progress In Astronomy

基　　金：国家自然科学基金(11803081)。

摘　　要：使用不同于传统的类傅里叶方法的celerite方法分析耀变体4C 01.02的γ射线和射电波段的长期光变特征。结果表明celerite中最简单的阻尼随机游走模型(damped random walk,DRW)可以成功地拟合射电和γ射线的长期光变曲线,而较为复杂的二阶随机过程(stochastically-driven,damped harmonic oscillator,SHO)并没有显著提升拟合优度。得到的内禀的γ射线光变特征时标约为3 a,如此长的时标不能在轻子辐射模型中产生,但是在强子模型中是可能存在的,由此推测4C 01.02长期的γ射线辐射可能起源于强子过程。射电光变的内禀特征时标约为10 a,它可能对应于射电辐射区的逃逸时标,这表明射电辐射产生于大尺度喷流。Here,we use the celerite method,which is different from the traditional Fourierlike methods,to analyze the γ-ray and radio long-term variabilities of 4C 01.02.The results show that the simplest kernel in celerite,damped random walk(DRW),can successfully fit both radio and γ-ray long-term light curves,and the more complex second-order stochastic process(stochastically-driven damped harmonic oscillator,SHO) does not significantly improve the goodness of fit.The intrinsic characteristic timescale of γ-ray variability is about 3 a,and such a long timescale cannot be generated in the leptonic emission model,but it is allowed in the hadronic model.We therefore speculate that the long-term γ-ray emission of 4C 01.02 may originate from hadronic process.The intrinsic characteristic timescale of radio variability is about 10 a.It may correspond to the escape timescale of the radio emission region,indicating that radio emission is produced in the large-scale jet.

关 键 词：活动星系核 耀变体 射电光变 γ射线光变 celerite方法 

分 类 号：P157.7[天文地球—天文学]