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arXiv 1005.5243astro-ph.HE
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船帆座X-1的X射线变化统计和风聚集

X-ray variation statistics and wind clumping in Vela X-1

Felix Fürst, Ingo Kreykenbohm, Katja Pottschmidt, Jörn Wilms, Manfred Hanke, Richard E. Rothschild, Peter Kretschmar, Norbert S. Schulz, David P. Huenemoerder, … 展开作者

Felix Fürst, Ingo Kreykenbohm, Katja Pottschmidt, Jörn Wilms, Manfred Hanke, Richard E. Rothschild, Peter Kretschmar, Norbert S. Schulz, David P. Huenemoerder, Dmitry Klochkov, Rüdiger Staubert

摘要:

通过分析中子星X射线双星系统Vela X-1的耀斑行为,研究了其星风的结构。船帆座X-1显示出持续的耀斑,其中一些耀斑在20-60 keV之间达到超过3.0 Crab的通量达100秒,而平均通量约为250 mCrab。我们分析了所有存档的INTEGRAL数据,计算了20-60 keV波段的亮度分布,正如我们所示,它严格遵循对数正态分布。轨道分辨分析表明,该结构是强可变的,可以解释的冲击和波动的吸积尾流。对RXTE ASM数据的分析表明,N_H的轨道发生了强烈的变化。由INTEGRAL数据得到的吸积团块质量约为5 × 10^19 - 10^21 g。我们表明,光变曲线可以描述与模型的乘法随机数。在模拟过程中,我们计算了系统在20-100 keV能量带的功率谱密度,并表明它遵循红噪声功率定律。我们认为,混合cloudsmooth风,冲击和湍流可以解释测量的质量分布。由于最近发现的一类超巨星快速X射线瞬变(SFXT)似乎显示出相同的风参数,因此持久的HMXB(如船帆座X-1)和SFXT之间的联系进一步加强。

英文摘要:

We investigate the structure of the wind in the neutron star X-ray binary system Vela X-1 by analyzing its flaring behavior. Vela X-1 shows constant flaring, with some flares reaching fluxes of more than 3.0 Crab between 20-60 keV for several 100 seconds, while the average flux is around 250 mCrab. We analyzed all archival INTEGRAL data, calculating the brightness distribution in the 20-60 keV band, which, as we show, closely follows a log-normal distribution. Orbital resolved analysis shows that the structure is strongly variable, explainable by shocks and a fluctuating accretion wake. Analysis of RXTE ASM data suggests a strong orbital change of N_H. Accreted clump masses derived from the INTEGRAL data are on the order of 5 x 10^19 -10^21 g. We show that the lightcurve can be described with a model of multiplicative random numbers. In the course of the simulation we calculate the power spectral density of the system in the 20-100 keV energy band and show that it follows a red-noise power law. We suggest that a mixture of a clumpy wind, shocks, and turbulence can explain the measured mass distribution. As the recently discovered class of supergiant fast X-ray transients (SFXT) seems to show the same parameters for the wind, the link between persistent HMXB like Vela X-1 and SFXT is further strengthened.

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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