Turbulent Model of Crab Nebula Radiation
Turbulent Model of Crab Nebula Radiation
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DOI：
10.3847/1538-4357/ab93c0
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发表时间：
2020-05
期刊：
影响因子：
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通讯作者：
Yonggang Luo;M. Lyutikov;T. Temim;L. Comisso
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文献类型：
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作者：
Yonggang Luo;M. Lyutikov;T. Temim;L. Comisso
我们构建了蟹状星云非热发射的湍流模型。本模型解决了 Kennel-Coroniti 模型的许多长期存在的问题：(i) 西格玛问题，(ii) 射电电子的硬谱，(iii) 伽马射线耀斑的高峰值能量，(iv) 和红外 (IR) 发射的空间演化。星云包含两种注入粒子：成分-I，通过费米-I 机制在风终止激波处加速；成分-I，通过费米-I 机制在风终止激波处加速；组分-II，在蟹状星云中心部分的高磁化（σ≫1）等离子体中加速重新连接湍流。第二部分中的重联湍流从射电延伸到伽马射线：它以硬谱加速射电电子，破坏大尺度磁通量（从而解决西格玛问题），并偶尔产生伽马射线耀斑（来自最大规模的重联事件）。该模型再现了蟹状星云的宽带光谱，从无线电中的低频同步加速器发射到 TeV 能量的逆康普顿发射，以及红外和光学波段光谱指数的空间分辨演化。
We construct a turbulent model of the Crab Nebula’s nonthermal emission. The present model resolves a number of long-standing problems of the Kennel–Coroniti model: (i) the sigma problem, (ii) the hard spectrum of radio electrons, (iii) the high peak energy of gamma-ray flares, (iv) and the spatial evolution of the infrared (IR) emission. The Nebula contains two populations of injected particles: Component-I, accelerated at the wind termination shock via the Fermi-I mechanism; and Component-II, accelerated in reconnecting turbulence in highly magnetized (σ ≫ 1) plasma in the central part of the Crab Nebula. The reconnecting turbulence in Component-II extends from radio to gamma-rays: it accelerates radio electrons with a hard spectrum, destroys the large-scale magnetic flux (and thus resolves the sigma problem), and occasionally produces gamma-ray flares (from the largest-scale reconnection events). The model reproduces the broadband spectrum of the Crab Nebula, from low-frequency synchrotron emission in radio to inverse-Compton emission at TeV energies, as well as the spatially resolved evolution of the spectral indices in the IR and optical bands.