Extended X-ray emission from non-thermal sources in the COSMOS field: a detailed study of a large radio galaxy at z= 1.168
Extended X-ray emission from non-thermal sources in the COSMOS field: a detailed study of a large radio galaxy at z= 1.168
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DOI：
10.1111/j.1365-2966.2012.21085.x
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发表时间：
2012-04
影响因子：
4.8
通讯作者：
V. Jelić;V. Smolčić;A. Finoguenov;Masayuki Tanaka;F. Civano;E. Schinnerer;N. Cappelluti;A. Koekemoer-A.-Ko
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文献类型：
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作者：
V. Jelić;V. Smolčić;A. Finoguenov;Masayuki Tanaka;F. Civano;E. Schinnerer;N. Cappelluti;A. Koekemoer-A.-Ko
X射线选择星系群样本通常是通过寻找扩展的X射线源，反映了热辐射的星系群内的介质。另一方面，有规律地占据星系群的大射电星系也会在X射线窗口中发射，它们对X射线选择群样本的贡献仍然没有得到很好的理解。为了研究它们的相对重要性，我们在宇宙演化巡天（COSMOS）领域中对非热扩展X射线源进行了系统的搜索。基于X射线和射电扩展的形态学重合，在60个射电星系中，和10000个扩展X射线源，我们发现只有一个候选者，所观察到的扩展X射线发射来自与射电星系相关的非热过程。我们对这个来源及其环境进行了详细的分析。我们的研究结果得出，外部逆康普顿发射的叶是占主导地位的过程，产生我们的扩展X射线候选人观察到的X射线发射，与微小的贡献，从气体的星系群托管的射电星系。最后，我们证明了在COSMOS场中只找到一个潜在的候选者（在红移范围0 - 1的星系团计数在明亮的一端（SX > 7 × 10 - 15 erg s-1 cm 2）。
X-ray selected galaxy group samples are usually generated by searching for extended X-ray sources that reflect the thermal radiation of the intragroup medium. On the other hand, large radio galaxies that regularly occupy galaxy groups also emit in the X-ray window, and their contribution to X-ray selected group samples is still not well understood. In order to investigate their relative importance, we have carried out a systematic search for non-thermal extended X-ray sources in the Cosmic Evolution Survey (COSMOS) field. Based on the morphological coincidence of X-ray and radio extensions, out of 60 radio galaxies, and ∼300 extended X-ray sources, we find only one candidate where the observed extended X-ray emission arises from non-thermal processes related to radio galaxies. We present a detailed analysis of this source, and its environment. Our results yield that external inverse Compton emission of the lobes is the dominant process that generates the observed X-ray emission of our extended X-ray candidate, with a minor contribution from the gas of the galaxy group hosting the radio galaxy. Finally, we show that finding only one potential candidate in the COSMOS field (in a redshift range 0 1 cluster counts at the bright end (SX > 7 × 10−15 erg s−1 cm2).