An X-ray survey of the 2 Jy sample - II. X-ray emission from extended structures
An X-ray survey of the 2 Jy sample - II. X-ray emission from extended structures
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DOI：
10.1093/mnras/stx1307
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发表时间：
2017-05
影响因子：
4.8
通讯作者：
B. Mingo;M. Hardcastle;J. Ineson;V. Mahatma;J. Croston;D. Dicken;D. Evans;R. Morganti;C. Tadhunter
中科院分区：
文献类型：
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作者：
B. Mingo;M. Hardcastle;J. Ineson;V. Mahatma;J. Croston;D. Dicken;D. Evans;R. Morganti;C. Tadhunter
2 Jy 样本是对 2.7 GHz 下通量密度高于 2 Jy 的射电星系的调查。作为我们正在进行的 2 Jy 源南部子集工作的一部分，在本系列的论文 I 中，我们分析了红移 0.05 < z < 0.7 的完整 2 Jy 样本的 X 射线核心。在这项工作中，我们重点关注与钱德拉观测到的 2 Jy 源（0.05 < z < 0.2）的完整子集的扩展结构（射流、波瓣和环境）相关的 X 射线发射。我们发现热点和黑流结在 Fanaroff-Riley II 类 (FRII) 源中普遍存在，其所处的环境也比我们样本中的 Fanaroff-Riley I 类 (FRI) 源系统更恶劣。具有良好 X 射线统计数据的热点的光谱拟合总是显示出与同步加速器发射一致的特性，并且我们表明逆康普顿机制将我们观察到的 X 射线发射低估了 1-2 个数量级。我们的样本中的许多波瓣都检测到了逆康普顿发射，我们发现 FRII 源的波瓣显示的磁场比均分外推法预期的低一个数量级。这与之前的结果一致，之前的结果表明大多数 FRII 源的电子能量密度高于最低能量需求。
The 2 Jy sample is a survey of radio galaxies with flux densities above 2 Jy at 2.7 GHz. As part of our ongoing work on the southern subset of 2 Jy sources, in paper I of this series we analysed the X-ray cores of the complete 2 Jy sample with redshifts 0.05 < z < 0.7. For this work we focus on the X-ray emission associated with the extended structures (jets, lobes, and environments) of the complete subset of 2 Jy sources with 0.05 < z < 0.2 that we have observed with Chandra. We find that hotspots and jet knots are ubiquitous in Fanaroff- Riley class II (FRII) sources, which also inhabit systematically poorer environments than the Fanaroff-Riley class I (FRI) sources in our sample. Spectral fits of the hotspots with good X-ray statistics invariably show properties consistent with synchrotron emission, and we show that inverse-Compton mechanisms underpredict the X-ray emission we observe by 1-2 orders of magnitude. Inverse-Compton emission is detected from many of the lobes in our sample, and we find that the lobes of the FRII sources show magnetic fields lower by up to an order of magnitude than expected from equipartition extrapolations. This is consistent with previous results, which show that most FRII sources have electron energy densities higher than minimum energy requirements.