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arXiv 1208.4564astro-ph.HEastro-ph.CO
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3C454.3在2010年11月至2011年1月爆发期间的多波长变化

Multiwavelength Variations of 3C 454.3 during the November 2010 to January 2011 Outburst

Ann E. Wehrle, Alan P. Marscher, Svetlana G. Jorstad, Mark A. Gurwell, Manasvita Joshi, Nicholas R. MacDonald, Karen E. Williamson, Ivan Agudo, Dirk Grupe

摘要:

我们目前的多波长数据的耀变体3C 454.3在一个非常明亮的爆发从2010年11月到2011年1月。这些包括赫歇尔空间天文台在五个亚毫米波和远红外波段的通量密度测量,费米大面积望远镜在伽马射线能量,斯威夫特在X射线,紫外线(UV)和光学频率,以及亚毫米阵列在1.3毫米。我们形成了一系列52个频谱能量分布(SED),跨越近两个月,在时间覆盖和频率宽度上是前所未有的。毫米波、远红外和伽马射线光变曲线的离散相关分析表明,在这些波段,这些变化基本上是同时的,表明了发射的共空间性。相反,在不同波长的短期波动的差异意味着存在的inhomogeneities在整个源的物理条件。我们将爆发的地点定位在秒差距尺度的核心,在爆发的前五周内,7毫米甚长基线阵列图像测量的通量密度增加了70%。基于这些考虑和引导的SED,我们提出了一个模型,在该模型中,湍流等离子体穿过一个圆锥形的驻激波在秒差距尺度区域的射流。在这里,模型中的高能辐射是由种子光子的逆康普顿散射产生的,种子光子由马赫盘的非热辐射、热尘埃的热辐射或(对于X射线)穿过驻波激波的等离子体的同步辐射提供。对于两个日期,我们拟合模型SED的数据,该模型对应于非常好的观察,在所有波段,除了在X射线能量,其中的光谱比观察到的平坦。

英文摘要:

We present multiwavelength data of the blazar 3C 454.3 obtained during an extremely bright outburst from November 2010 through January 2011. These include flux density measurements with the Herschel Space Observatory at five submillimeter-wave and far-infrared bands, the Fermi Large Area Telescope at gamma-ray energies, Swift at X-ray, ultraviolet (UV), and optical frequencies, and the Submillimeter Array at 1.3 mm. From this dataset, we form a series of 52 spectral energy distributions (SEDs) spanning nearly two months that are unprecedented in time coverage and breadth of frequency. Discrete correlation anlaysis of the millimeter, far-infrared, and gamma-ray light curves show that the variations were essentially simultaneous, indicative of co-spatiality of the emission, at these wavebands. In contrast, differences in short-term fluctuations at various wavelengths imply the presence of inhomegeneities in physical conditions across the source. We locate the site of the outburst in the parsec-scale core, whose flux density as measured on 7 mm Very Long Baseline Array images increased by 70 percent during the first five weeks of the outburst. Based on these considerations and guided by the SEDs, we propose a model in which turbulent plasma crosses a conical standing shock in the parsec-scale region of the jet. Here, the high-energy emission in the model is produced by inverse Compton scattering of seed photons supplied by either nonthermal radiation from a Mach disk, thermal emission from hot dust, or (for X-rays) synchrotron radiation from plasma that crosses the standing shock. For the two dates on which we fitted the model SED to the data, the model corresponds very well to the observations at all bands except at X-ray energies, where the spectrum is flatter than observed.

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