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arXiv 1609.07530astro-ph.HE
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用XMM-牛顿和NuSTAR在非常低的光度下观测到的GRS 1739-278

GRS 1739-278 observed at very low luminosity with XMM-Newton and NuSTAR

F. Fuerst, J. A. Tomsick, K. Yamaoka, T. Dauser, J. M. Miller, M. Clavel, S. Corbel, A. C. Fabian, J. Garcia, F. A. Harrison, A. Loh, P. Kaaret, E. Kalemci, S. … 展开作者

F. Fuerst, J. A. Tomsick, K. Yamaoka, T. Dauser, J. M. Miller, M. Clavel, S. Corbel, A. C. Fabian, J. Garcia, F. A. Harrison, A. Loh, P. Kaaret, E. Kalemci, S. Migliari, J. C. A. Miller-Jones, K. Pottschmidt, F. Rahoui, J. Rodriguez, D. Stern, M. Stuhlinger, D. J. Walton, J. Wilms

摘要:

本文详细地分析了XMM-牛顿和NuSTAR观测到的GRS 1739-278吸积瞬态黑洞在爱丁顿光度的0.02%(距离为8.5 kpc,质量为10 M_sun)的非常微弱的低硬态的光谱。在0.5-60 keV之间的宽波段X射线谱可以很好地用具有指数截止的幂律连续谱来描述。对于如此低的光度,连续谱异常困难,光子指数为Gamma = 1.39 +/- 0.04。我们发现一个额外的反射组件从光学厚吸积盘在98%的可能性水平的证据。反射率较低,R_refl = 0.043(+0.033,-0.023)。结合米勒及其同事在较亮的硬态期间用NuSTAR测量的自旋和倾斜参数,我们试图限制吸积盘的几何形状。根据假设的吸积盘的发射率分布,我们发现在90%的置信限下,截断半径为15-35 Rg(5-12 R_ISCO)。这些值强烈依赖于假设,我们讨论了可能的系统不确定性。

英文摘要:

We present a detailed spectral analysis of XMM-Newton and NuSTAR observations of the accreting transient black hole GRS 1739-278 during a very faint low hard state at ~0.02% of the Eddington luminosity (for a distance of 8.5 kpc and a mass of 10 M_sun ). The broad-band X-ray spectrum between 0.5-60 keV can be well-described by a power law continuum with an exponential cutoff. The continuum is unusually hard for such a low luminosity, with a photon index of Gamma = 1.39 +/- 0.04. We find evidence for an additional reflection component from an optically thick accretion disk at the 98% likelihood level. The reflection fraction is low with R_refl = 0.043(+0.033,-0.023). In combination with measurements of the spin and inclination parameters made with NuSTAR during a brighter hard state by Miller and co-workers, we seek to constrain the accretion disk geometry. Depending on the assumed emissivity profile of the accretion disk, we find a truncation radius of 15-35 Rg (5-12 R_ISCO ) at the 90% confidence limit. These values depend strongly on the assumptions and we discuss possible systematic uncertainties.

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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