Radio haloes in Sunyaev–Zel'dovich-selected clusters of galaxies: the making of a halo?
Radio haloes in Sunyaev–Zel'dovich-selected clusters of galaxies: the making of a halo?
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DOI：
10.1093/mnras/stv2065
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发表时间：
2015-09
影响因子：
4.8
通讯作者：
A. Bonafede;H. Intema;M. Brüggen;F. Vazza;K. Basu;M. Sommer;H. Ebeling;F. Gasperin;H. Röttgering;R. Weeren;R. Cassano
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文献类型：
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作者：
A. Bonafede;H. Intema;M. Brüggen;F. Vazza;K. Basu;M. Sommer;H. Ebeling;F. Gasperin;H. Röttgering;R. Weeren;R. Cassano
射电晕是在一些大质量星系团中探测到的同步加速器射电源。它们的MPC大小表明(重新)加速过程正在主机群集中进行。星系团的X射线星表过去被用来搜索射电晕，并了解它们与星系团合并和星系团内介质的热成分之间的联系。最近，Sunyaev-Zel‘dovich效应已被证明是在更大的红移范围内寻找大质量星系团的更好途径。为了发现新的射电晕并了解它们与星系团合并的联系，我们从普朗克早期源目录中选择了最大质量的星系团，并用323 MHz的巨型米波射电望远镜观测到了那些无法进行深入观测的天体。我们在其中三个观测星系团中发现了新的特殊射电辐射，发现：(I)星系团RXCJ0949.8+1708中有射电晕；(Ii)Abell 1443星系团的扩展发射，我们将其归类为射电晕加射电遗迹，在射电晕中嵌入了一根明亮的灯丝；(Iii)在CIZA J1938.3+5409中发现了比射电-X射线关联低10倍的低功率射电发射，这是首次在射电-X射线图的“上限”区域直接探测到射电辐射。我们在射电辐射理论模型的框架内讨论了这些新射电晕的性质。
Radio halos are synchrotron radio sources detected in some massive galaxy clusters. Their Mpc-size indicates that (re)acceleration processes are taking place in the host cluster. X-ray catalogues of galaxy clusters have been used in the past to search for radio halos and to understand their connection with cluster-cluster mergers and with the thermal component of the intra-cluster medium. More recently, the Sunyaev-Zel'dovich effect has been proven to be a better route to search for massive clusters in a wider redshift range. With the aim of discovering new radio halos and understanding their connection with cluster-cluster mergers, we have selected from the Planck Early source catalog the most massive clusters, and we have observed with the Giant Metrewave Radio Telescope at 323 MHz those objects for which deep observations were not available. We have discovered new peculiar radio emission in three of the observed clusters finding: (i) a radio halo in the cluster RXCJ0949.8+1708; (ii) extended emission in Abell 1443 that we classify as a radio halo plus a radio relic, with a bright filament embedded in the radio halo; (iii) low-power radio emission is found in CIZA J1938.3+5409 which is ten times below the radio - X-ray correlation, and represents the first direct detection of the radio emission in the "upper-limit" region of the radio - X-ray diagram. We discuss the properties of these new radio halos in the framework of theoretical models for the radio emission.