arXiv 1708.044272017-08astro-ph.HE

X射线双星光谱中的高能幂律尾与源自盘的锥形外流引起的体Comptonization

High energy power-law tail in X-ray binaries spectrum and bulk Comptonization due to a conical outflow from a disk

Nagendra Kumar

备注：: 5 figures, accepted for publication in JHEAP
DOI：: 10.1016/j.jheap.2025.100503

阅读 PDF

arXiv 页面 ↗HTML 原文 ↗

AI总结：

研究X射线双星高能幂律尾的体Comptonization过程，提出锥形外流几何模型，通过Monte Carlo模拟发现仅当开角大于30度时能产生幂律尾，并成功解释了GRS 1915+105光谱。

摘要：

X射线双星（XRBs）通常表现出高能幂律尾（HEP-tail），这些尾部可以通过具有向致密天体自由下落体区域的体Comptonization（BMC）过程产生。在XRBs的所有光谱态中都观测到了射电辐射（由同步辐射的外流电子产生）。有趣的是，不同光谱态之间HEP-tail通量的变化与射电通量的变化相似。我们旨在研究具有外流介质的BMC过程中的HEP-tail。为此，我们考虑了一种准直且锥形（开角为$θ_b$，轴垂直于吸积盘）的外流几何结构。我们使用Monte Carlo方案模拟了BMC光谱。我们发现，仅当锥形外流中$θ_b$大于约30度时，出射光谱才具有幂律尾（光子指数$Γ$ $>$ 2且高能截断$E_{c}$ $>$ 200 keV），而对于准直或锥形外流（$θ_b$ $<$ 30度），这些HEP-tail只能在热Comptonization光谱中也出现时（即在足够高的Comptonization介质温度下）才能产生。这些结果与解析推导的表达式大致一致。我们描述了锥形外流中观测到的GRS 1915+105光谱的两类（$χ$和$γ$），为此外流速度是高度相对论性的，且风的动能功率表明HEP-tail可以在吸积盘内部区域产生，如同内盘射电辐射一样。

英文摘要：

X-ray binaries (XRBs) often exhibit a high energy power-law tail (HEP-tail) and these tails can be generated by the bulk Comptonization (BMC) process with a free-fall bulk region onto the compact object. The radio emission (which is generated by a synchrotron-emitting outflowing electrons) is observed in all spectral state of XRBs. Interestingly, the variations of HEP-tail flux among different spectral states is similar to the variation of radio flux. We motivate to study the HEP-tail in BMC process with an outflowing medium. For this we consider a collimated and conical (of opening angle $θ_b$ with axis perpendicular to the accretion disk) outflow geometry. We simulate the BMC spectrum by using a Monte Carlo scheme. We find that the emergent spectrum has power-law tail (of photon index $Γ$ $>$ 2 and with high energy cut-off $E_{c}$ $>$ 200 keV) only for $θ_b$ greater than $\sim$30 degrees in conical outflow, while for a collimated or a conical outflow ($θ_b$ $<$ 30 degrees) these HEP-tail can be only generated when it is also found in thermal Comptonized spectra (i.e., at sufficiently high Comptonizing medium temperature). These results are approximately consistent with analytically derived expressions. We describe the observed GRS 1915+105 spectrum for two classes $χ$ and $γ$ in conical outflow, for this the outflow speed is highly relativistic and the kinetic power of wind suggest that the HEP-tail can be generated at inner region of the accretion disk, like inner disk radio emission.

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。

AI总结：

摘要：

英文摘要：

相关论文