论文标题
磁场和相对论电子填充整个星系群
Magnetic fields and relativistic electrons fill entire galaxy cluster
论文作者
论文摘要
预计合并星系簇中的热等离子体充满了冲击和湍流，可能会将其动能的一部分转换为相对论电子和产生同步辐射的磁场。分析星系群集Abell 2255的低频阵列（Lofar）观察结果，我们显示了无线电同步发射的证据，分布在至少5兆帕的非常大的尺度上。普遍的无线电发射见证了震动和湍流有效地将动能传递到相对论颗粒和磁场的区域中的区域，该区域延伸到群集郊区。发射的强度需要比原始场的简单压缩的预期高100倍的磁场能密度，这大概意味着Dynamo在群集外围也有效地运行。这也表明，非热成分可能对群集外围的簇内培养基的压力产生重大贡献。
The hot plasma within merging galaxy clusters is predicted to be filled with shocks and turbulence that may convert part of their kinetic energy into relativistic electrons and magnetic fields generating synchrotron radiation. Analyzing Low Frequency Array (LOFAR) observations of the galaxy cluster Abell 2255, we show evidence of radio synchrotron emission distributed over very large scales of at least 5 megaparsec. The pervasive radio emission witnesses that shocks and turbulence efficiently transfer kinetic energy into relativistic particles and magnetic fields in a region that extends up to the cluster outskirts. The strength of the emission requires a magnetic field energy density at least 100 times higher than expected from a simple compression of primordial fields, presumably implying that dynamo operates efficiently also in the cluster periphery. It also suggests that nonthermal components may contribute substantially to the pressure of the intracluster medium in the cluster periphery.
