Nonthermal emission from relativistic electrons in clusters of galaxies: A merger shock acceleration model

被引:50
作者
Takizawa, M [1 ]
Naito, T
机构
[1] Kyoto Univ, Fac Sci, Dept Astron, Sakyo Ku, Kyoto 6068502, Japan
[2] Univ Tokyo, Grad Sch Sci, Res Ctr Early Universe, Bunkyo Ku, Tokyo 1130033, Japan
[3] Yamagata Univ, Dept Phys, Yamagata 9908560, Japan
[4] Yamanashi Gakuin Univ, Dept Management Informat, Koufu Si, Yamanashi 4008575, Japan
关键词
acceleration of particles; galaxies : clusters : general; hydrodynamics; intergalactic medium; radiation mechanisms : nonthermal;
D O I
10.1086/308894
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We have investigated evolution of nonthermal emission from relativistic electrons accelerated around the shock fronts during mergers of clusters of galaxies. We estimate synchrotron radio emission and inverse Compton scattering of cosmic microwave background photons from extreme ultraviolet (EUV) to hard X-ray range. The hard X-ray emission is most luminous in the later stage of a merger. Both hard X-ray and radio emissions are luminous only while signatures of merging events are clearly seen in the thermal intracluster medium (ICM). On the other hand, EW radiation is still luminous after the system has relaxed. Propagation of shock waves and bulk-flow motion of ICM play crucial roles in extending radio halos. In the contracting phase, radio halos are located at the hot region of ICM or between two substructures. In the expanding phase, on the other hand, radio halos are located between two ICM hot regions and show rather diffuse distribution.
引用
收藏
页码:586 / 592
页数:7
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