Long-term multi-wavelength variations of Fermi blazar 3C 279  

作　　者：Bing-Kai Zhang Min Jin Xiao-Yun Zhao Li Zhang Ben-Zhong Dai 

机构地区：[1]Department of Physics,Fuyang Normal University,Fuyang 236037,China [2]Key Laboratory of Functional Materials and Devices for Informatics of Anhui Higher Education Institutes,Fuyang Normal University,Fuyang 236037,China [3]Department of Astronomy,Yunnan University,Kunming 650091,China

出　　处：《Research in Astronomy and Astrophysics》2021年第8期5-15,共11页天文和天体物理学研究（英文版）

基　　金：the support from National Natural Science Foundation of China (NSFC,Nos.U1831124 and 11273008);the Natural Science Foundation of Anhui Province of China (Grant No.1908085MA28)。

摘　　要：Long-term optical,X-ray and γ-ray data of blazar 3 C 279 have been compiled from Swift-XRT,RXTE-PCA,Fermi-LAT,SMARTS and literature.The source exhibits strong variability on long timescales.From the 1980 s until now,the optical R band light curve spans more than 32 yr,and a possible 5.6-yr-long quasi-periodic variation component has been found in it.The optical spectral behavior has been investigated.In the optical band,the mean spectral index is –1.71.The source exhibits an obvious special spectral behavior.In the low state,the source manifests a clear bluer-when-brighter behavior in the sense that the optical spectrum turns harder(flatter) when the brightness increases.While in the high state,the optical spectrum is stable,which means the source spectral index does not vary with brightness.The correlation analysis has been performed among optical,X-ray and γ-ray energy bands.The result indicates that the variations of γ-ray and X-ray bands are well correlated without time delay on the timescale of days,and their variations exhibit weak correlations with those of the optical band.The variations,especially outbursts,are simultaneous,but the magnitude of variations is disproportionate.The detailed analysis reveals that the main outbursts exhibit strong correlations in different γ-ray,X-ray and optical bands.

关 键 词：galaxies:active BL Lacertae objects:general quasars:general quasars:individual(3C 279) 

分 类 号：P158[天文地球—天文学]