Correlated Multi-Wave Band Variability in the Blazar 3C 279 from 1996 to 2007
Correlated Multi-Wave Band Variability in the Blazar 3C 279 from 1996 to 2007
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DOI：
10.1086/592598
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发表时间：
2008-08
期刊：
影响因子：
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通讯作者：
R. Chatterjee;S. Jorstad;S. Jorstad;A. Marscher;Haruki Oh;Haruki Oh;I. McHardy;M. Aller;H. Aller
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文献类型：
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作者：
R. Chatterjee;S. Jorstad;S. Jorstad;A. Marscher;Haruki Oh;Haruki Oh;I. McHardy;M. Aller;H. Aller
我们给出了1996至2007年间在X射线能量(2-10keV)、光学R波段和14.5 GHz下对Blaazar 3C279进行的广泛的多波段监测结果，以及43 GHz甚长基线阵列(VLBA)的成像结果。在所有频段中，功率谱密度对应于“红色噪声”，它可以在采样时间尺度上以单一的幂定律来拟合。这三个波段的通量变化是显著相关的。高频和低频频段之间的时间延迟在几年的时间尺度上有很大的变化。2001年的一次主要的多频耀斑恰逢喷流向更南边的方向摆动，总体上，X射线通量受喷流在核心附近位置角的变化所调制。中心43 GHz处的通量密度--增加表明出现了新的超光速结--与X射线通量显著相关。我们将X射线和光学光曲线分解成单独的耀斑，发现在六个耀斑中X射线导致光学变化(XO)，在三个耀斑中出现反转(OX)，在四个耀斑中基本上没有滞后。通过比较理论预期和数据，我们得出结论：(1)XO耀斑可以由辐射电子逐渐加速到最高能量来解释，(2)OX耀斑可以由种子光子的光传播延迟(同步加速器自康普顿散射)或激波锋面后最大电子能量的梯度引起，(3)具有相似X射线和光辐射输出的事件发生在43 GHz核的上游，而以光辐射输出为主的事件发生在核的下游或附近。
We present the results of extensive multi-wave band monitoring of the blazar 3C 279 between 1996 and 2007 at X-ray energies (2-10 keV), optical R band, and 14.5 GHz, as well as imaging with the Very Long Baseline Array (VLBA) at 43 GHz. In all bands the power spectral density corresponds to “red noise” that can be fit by a single power law over the sampled timescales. Variations in flux at all three wave bands are significantly correlated. The time delay between high- and low-frequency bands changes substantially on timescales of years. A major multifrequency flare in 2001 coincided with a swing of the jet toward a more southerly direction, and in general the X-ray flux is modulated by changes in the position angle of the jet near the core. The flux density in the core at 43 GHz—increases in which indicate the appearance of new superluminal knots—are significantly correlated with the X-ray flux. We decompose the X-ray and optical light curves into individual flares, finding that X-ray leads optical variations (XO) in six flares, the reverse (OX) occurs in three flares, and there is essentially zero lag in four flares. Upon comparing theoretical expectations with the data, we conclude that (1) XO flares can be explained by gradual acceleration of radiating electrons to the highest energies, (2) OX flares can result from either light-travel delays of the seed photons (synchrotron self-Compton scattering) or gradients in maximum electron energy behind shock fronts, and (3) events with similar X-ray and optical radiative energy output originate well upstream of the 43 GHz core, while those in which the optical radiative output dominates occur at or downstream of the core.