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arXiv 0910.3947astro-ph.HEastro-ph.CO
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活动星系核中相对论性铁谱线的分布和宇宙密度

The Distribution and Cosmic Density of Relativistic Iron Lines in Active Galactic Nuclei

D. R. Ballantyne

摘要:

几个活动星系核的X射线观测显示,由于特殊和广义相对论效应,铁K壳层荧光线被雕刻出来。这些观测很重要,因为它们探测了遥远的黑洞附近的时空几何。然而,Fe线强度在宇宙中的内在分布从未被确定。这种不确定性导致了围绕发射特征的相对论解释的争议。现在,通过利用最新的多波长数据,我们给出了相对论Fe线的宇宙密度作为其等效宽度和线通量的函数的理论预测。我们能够明确地表明,宇宙中最常见的相对论性铁谱线将由塞弗特星系中的中性铁荧光产生,并且具有小于100 eV的等效宽度。因此,已经发现的极少数非常强的谱线只是谱线强度分布的亮点。除了验证目前的观测结果,预测的分布可以用于规划未来的调查相对论Fe线。最后,预测的天空密度的等效宽度表明,在活动星系核的X射线源不能,平均而言,位于轴上的黑洞。

英文摘要:

X-ray observations of several active galactic nuclei show prominent iron K-shell fluorescence lines that are sculpted due to special and general relativistic effects. These observations are important because they probe the space-time geometry close to distant black holes. However, the intrinsic distribution of Fe line strengths in the cosmos has never been determined. This uncertainty has contributed to the controversy surrounding the relativistic interpretation of the emission feature. Now, by making use of the latest multi-wavelength data, we show theoretical predictions of the cosmic density of relativistic Fe lines as a function of their equivalent width and line flux. We are able to show unequivocally that the most common relativistic iron lines in the universe will be produced by neutral iron fluorescence in Seyfert galaxies and have equivalent widths < 100 eV. Thus, the handful of very intense lines that have been discovered are just the bright end of a distribution of line strengths. In addition to validating the current observations, the predicted distributions can be used for planning future surveys of relativistic Fe lines. Finally, the predicted sky density of equivalent widths indicate that the X-ray source in AGNs can not, on average, lie on the axis of the black hole.

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。

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