Discovery of Kolmogorov-like magnetic energy spectrum in Tycho’s supernova remnant by two-point correlations of synchrotron intensity

The spectral slope of the magnetic energy in supernova remnants (SNRs) can be obtained by analysis of spatial two-point correlation functions of synchrotron intensities. This method has been originally developed for the analysis of magnetic field structure in diffuse interstellar medium and applied when the geometry of the emission region is simple and known. In this paper, applying this correlation analysis to Tycho's SNR, for which the synchrotron emission region is known to be a spherical shell, we find that the magnetic energy spectrum shows the Kolmogorov-like scaling. Our results can be explained by turbulence developed downstream of the shock front via Richtmyer-Meshkov instability or an amplification of upstream magnetic field induced by cosmic rays. They could be discriminated by future observations with a sub arcsecond resolution such as Square Kilometer Array.

超新星遗迹（SNRs）中磁能的谱斜率可通过对同步辐射强度的空间两点相关函数进行分析来获得。这种方法最初是为分析弥漫星际介质中的磁场结构而开发的，并且在发射区域的几何形状简单且已知的情况下应用。在本文中，将这种相关分析应用于第谷超新星遗迹（已知其同步辐射发射区域是一个球壳），我们发现磁能谱呈现出类似柯尔莫哥洛夫标度。我们的结果可以通过激波前沿下游经由 Richtmyer - Meshkov不稳定性产生的湍流，或者宇宙射线引起的上游磁场的放大来解释。它们可以通过诸如平方千米阵等具有亚角秒分辨率的未来观测加以区分。