The study on variation phenomena of blazars can shed light on the jet activity and structures. We collect nearly ten years γ-ray, X-ray, optical, and radio light curves of the target 3C 279, and use the local cross-correlation function to perform the correlation analysis among them. Based on lags among different wavelengths, we obtain that the optical as well as the X-ray emitting regions are 32.5−0.9+2.9 and 8.4−4.4+7.7 pc away from the jet base, and are upstream of the radio core region. The optical and γ-ray emitting regions are not completely co-spatial. We select several periods to study various variation phenomena at long-term, short-term, and very-short-term timescales. We find a redder when brighter trend of the optical color index at the quiescent state and a bluer when brighter trend at the active state. We also find a softer when brighter trend of the γ-ray at low luminosity and a possible harder when brighter trend at high luminosity. The correlation between the optical polarization and fluxes is complex. We find an anticorrelation for one long-term flare, and positive correlations for two short-term flares. The stack of the multiple optical components can explain the anticorrelation, while the appearance of a dominating component can explain the positive correlations. The disk plus many jet components scenario can explain the complex optical variation behaviors for 3C 279. As a remarkable intermediate synchrotron peaked blazar target, 3C 279 play an important role to understand the classification and transition between the low synchrotron peaked and high synchrotron peaked subclass of blazars, since its variation phenomena shows the indication of connection between these two categories.

中文翻译：

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3C 279 在不同时间尺度的多波长相关性和变化研究


对耀变体变化现象的研究可以揭示喷流的活动和结构。我们收集了3C 279目标近十年的γ射线、X射线、光学和射电光变曲线，并利用局部互相关函数对它们进行了相关分析。根据不同波长之间的滞后，我们得出光学和X射线发射区域距喷气机底座32.5−0.9+2.9和8.4−4.4+7.7 pc，并且位于无线电核心区域的上游。光学和γ射线发射区域并不完全共空间。我们选择几个时期来研究长期、短期和超短期时间尺度上的各种变化现象。我们发现，在静止状态下光学颜色指数呈现出越亮越红的趋势，而在活动状态下则呈现出越亮越蓝的趋势。我们还发现，在低光度下，γ 射线的亮度趋势较软，而在高光度下，γ 射线的亮度趋势可能较硬。光学偏振和通量之间的相关性很复杂。我们发现一次长期耀斑存在反相关性，而两次短期耀斑存在正相关性。多个光学元件的堆叠可以解释反相关性，而主导元件的出现可以解释正相关性。圆盘加上许多射流组件的场景可以解释 3C 279 复杂的光学变化行为。作为一个卓越的中间同步加速器峰值耀变体目标，3C 279 在理解低同步加速器峰值和高同步加速器峰值亚类之间的分类和过渡方面发挥着重要作用。耀变体，因为它的变化现象表明了这两个类别之间的联系。