arXiv 0802.42972008-02-28astro-ph

对低功率射电星系的环境、粒子含量和影响的XMM-牛顿研究

An XMM-Newton study of the environments, particle content and impact of low-power radio galaxies

J. H. Croston, M. J. Hardcastle, M. Birkinshaw, D. M. Worrall, R. A. Laing

备注：: 21 pages, 13 figures. Accepted for publication in MNRAS. Version with higher resolution figures available from http://hercules.herts.ac.uk/~jcroston/xmmfris.pdf
DOI：: 10.1111/j.1365-2966.2008.13162.x

摘要：

我们提出了一个详细的研究环境的一个样本的9个低功率射电星系，新的和档案XMM牛顿观测的基础上。我们报告了三个射电星系，3C 296，NGC 1044和3C 76.1周围的群尺度环境的新探测。与以前的研究一样，我们发现FR-I射电星系居住在辐射热X射线光度近两个数量级的群体环境中，但没有发现大尺度X射线环境与射电源属性（如大小，射电光度和轴比）之间存在紧密关系的证据。我们证实了早期的工作表明，均分内部压力通常低于外部压力作用于无线电波瓣，因此，额外的非辐射粒子必须存在或必须磁瓣占主导地位。我们提出了第一个直接的观测证据，夹带可能会提供这种失踪的压力，在放射源结构和明显的压力不平衡之间的关系的形式。最后，我们的研究提供了进一步的支持存在一个明显的温度过高的无线电大声组相比，作为一个整体的群体人口。在八个温度过剩的情况中，有五个情况下，使射电波瓣膨胀所需的能量与加热群气体产生这种过剩所需的能量相当;然而，在三个情况下，电流射电源似乎太弱，无法产生温度过剩。目前尚不清楚温度过高是否与活动星系核活动的当前阶段直接相关，或者它是否是以前活动星系核活动的标志，或者仅仅是最有利于FR-I射电星系生长的特定群体属性的指示器。

英文摘要：

We present a detailed study of the environments of a sample of nine low-power radio galaxies, based on new and archival XMM-Newton observations. We report new detections of group-scale environments around three radio galaxies, 3C 296, NGC 1044 and 3C 76.1. As with previous studies, we find that FR-I radio galaxies inhabit group environments ranging over nearly two orders of magnitude in bolometric X-ray luminosity, but find no evidence for a tight relationship between large-scale X-ray environment and radio-source properties such as size, radio luminosity, and axial ratio. We confirm earlier work showing that equipartition internal pressures are typically lower than the external pressures acting on the radio lobes, so that additional non-radiating particles must be present or the lobes must be magnetically dominated. We present the first direct observational evidence that entrainment may provide this missing pressure, in the form of a relationship between radio-source structure and apparent pressure imbalance. Finally, our study provides further support for the presence of an apparent temperature excess in radio-loud groups compared to the group population as a whole. For five of eight temperature excesses, the energy required to inflate the radio lobes is comparable to the energy required to produce this excess by heating of the group gas; however, in three cases the current radio source appears too weak to produce the temperature excess. It remains unclear whether the temperature excess can be directly associated with the current phase of AGN activity, or whether it is instead either a signature of previous AGN activity or simply an indicator of the particular set of group properties most conducive to the growth of an FR-I radio galaxy.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

摘要：

英文摘要：

相关论文