Planck early results. XV. Spectral energy distributions and radio continuum spectra of northern extragalactic radio sources
Planck early results. XV. Spectral energy distributions and radio continuum spectra of northern extragalactic radio sources
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DOI：
10.1051/0004-6361/201116466
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发表时间：
2011-12-01
影响因子：
6.5
通讯作者：
Zonca, A.
中科院分区：
文献类型：
--
作者：
Aatrokoski, J.;Ade, P. A. R.;Zonca, A.
根据普朗克早期发布的紧凑源目录（ERCSC）和同步多频数据，给出了北方104个河外射电源样本的谱能量分布（SED）和射电连续谱。从30到857 GHz的9个普朗克频率由一组从无线电到伽马射线的同步观测补充。这是第一次广泛的频率覆盖在无线电和毫米域的一个基本上完整的样本河外射电源，它显示了如何个别冲击，每个在自己的发展阶段，形状的无线电频谱，因为他们在相对论喷流。采用二次多项式和三次多项式拟合SED，计算了同步辐射峰和逆康普顿峰的频率，并计算了包括Planck ERCSC数据在内的低频和高频射电数据的谱指数。SED建模方法进行了讨论，重点是正确的，物理建模的同步加速器凸块使用多个组件。普朗克ERCSC数据还表明，最初的加速电子能谱可能比通常认为的要硬得多，幂律指数约为1.5，而不是典型的2.5。这一点的影响进行了讨论，有效的耀变体冲击的加速机制。此外，在许多情况下，普朗克数据表明，伽马射线发射必须起源于产生射电发射的同一个冲击。
Spectral energy distributions (SEDs) and radio continuum spectra are presented for a northern sample of 104 extragalactic radio sources, based on the Planck Early Release Compact Source Catalogue (ERCSC) and simultaneous multifrequency data. The nine Planck frequencies, from 30 to 857 GHz, are complemented by a set of simultaneous observations ranging from radio to gamma-rays. This is the first extensive frequency coverage in the radio and millimetre domains for an essentially complete sample of extragalactic radio sources, and it shows how the individual shocks, each in their own phase of development, shape the radio spectra as they move in the relativistic jet. The SEDs presented in this paper were fitted with second and third degree polynomials to estimate the frequencies of the synchrotron and inverse Compton (IC) peaks, and the spectral indices of low and high frequency radio data, including the Planck ERCSC data, were calculated. SED modelling methods are discussed, with an emphasis on proper, physical modelling of the synchrotron bump using multiple components. Planck ERCSC data also suggest that the original accelerated electron energy spectrum could be much harder than commonly thought, with power-law index around 1.5 instead of the canonical 2.5. The implications of this are discussed for the acceleration mechanisms effective in blazar shocks. Furthermore in many cases the Planck data indicate that gamma-ray emission must originate in the same shocks that produce the radio emission.