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arXiv 0911.2240astro-ph.HE
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低光度下黑洞周围内吸积盘的截断

Truncation of the Inner Accretion Disk around a Black Hole at Low Luminosity

John A. Tomsick, Kazutaka Yamaoka, Stephane Corbel, Philip Kaaret, Emrah Kalemci, Simone Migliari

摘要:

大多数黑洞双星的X射线光度变化很大,主要是由质量吸积率的变化引起的。理解黑洞吸积和喷流产生的一个重要问题是吸积盘的内边缘是否以低吸积速率后退。内边缘(Rin)的位置可以用铁的发射线来测量,这些发射线是由于圆盘中铁的荧光而产生的,这些发射线表明Rin在高和中等亮度(接近爱丁顿光度的1%,Ledd)时非常接近黑洞。在这里,我们报告了朱雀和罗西X射线计时探测器(RXTE)对黑洞GX 339-4在硬态下的X射线观测,将铁线研究扩展到0.14% Ledd,并表明Rin比GX 339-4明亮时的值增加了27倍。Rin的精确值取决于内盘的倾角(i),我们推导出在i = 0度时Rin > 35 Rg和在i = 30度时Rin > 175 Rg的90%置信限。这提供了直接的证据,表明盘的内部部分并不存在于低光度,允许内部盘被平流或磁主导的吸积流所取代的可能性。

英文摘要:

Most black hole binaries show large changes in X-ray luminosity caused primarily by variations in mass accretion rate. An important question for understanding black hole accretion and jet production is whether the inner edge of the accretion disk recedes at low accretion rate. Measurements of the location of the inner edge (Rin) can be made using iron emission lines that arise due to fluorescence of iron in the disk, and these indicate that Rin is very close to the black hole at high and moderate luminosities (near 1% of the Eddington luminosity, Ledd). Here, we report on X-ray observations of the black hole GX 339-4 in the hard state by Suzaku and the Rossi X-ray Timing Explorer (RXTE) that extend iron line studies to 0.14% Ledd and show that Rin increases by a factor of >27 over the value found when GX 339-4 was bright. The exact value of Rin depends on the inclination of the inner disk (i), and we derive 90% confidence limits of Rin > 35 Rg at i = 0 degrees and Rin > 175 Rg at i = 30 degrees. This provides direct evidence that the inner portion of the disk is not present at low luminosity, allowing for the possibility that the inner disk is replaced by advection- or magnetically-dominated accretion flows.

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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