标题： 类似 shot 噪声在 Cyg X-1、GRO J0422+32 和 1E 1724-3045 中出现 显示英文标题

标题： Similar Shot Noise in Cyg X-1, GRO J0422+32 and 1E 1724-3045

摘要： 我们研究了1997年1月17日和20日用Rossi时变探测器（RXTE）观测到的Cyg X-1的快速变化。低于200 Hz的功率谱可以用两个“短脉冲噪声”分量和一个中心频率为0.2 Hz的峰噪声来描述。这与另一个黑洞候选体GRO J0422+32以及中子星X射线双星1E 1724-3045所观测到的“短脉冲噪声”相似。这种相似性表明，“短脉冲噪声”和峰噪声的产生机制在黑洞系统和中子星系统中可能类似，并且在高质质量X射线双星（HMXBS）和低质量X射线双星（LMXBs）中也可能类似。我们还分析了从Cyg X-1光变曲线中选出的约500个最亮的短脉冲。短脉冲周围的能谱变化时间尺度可以长达几秒钟，这与Ginga的结果一致。不同能量带上的叠加短脉冲轮廓之间的差异可归因于不同能量带之间的时间延迟和短脉冲宽度的不同。由短脉冲轮廓的自相关函数定义的短脉冲宽度并未显示出双峰分布。 显示英文摘要

摘要： We study the rapid variability in Cyg X-1 observed with the Rossi Timing Explorer (RXTE) on Jan 17 and 20 of 1997. The power spectra below 200 Hz can be characterized by two ``shot noise'' components and a peaked-noise centered at 0.2 Hz. This is similar to those ``shot noise'' observed in another black hole candidate GRO J0422+32 and a neutron star X-ray binary 1E 1724-3045. The similarity suggests that the generation mechanism of ``shot noise'' and peaked-noise is probably similar in both black hole systems and neutron star systems, and in both high mass X-ray binaries (HMXBS) and low mass X-ray binaries (LMXBs). We have also analyzed ~ 500 brightest shots selected from the Cyg X-1 light curves. The time scale of the spectral variation around the shot can be as long as ~ a few seconds, consistent with Ginga results. The difference between the superposed shot profile in different energy bands can be attributed to the time lag and the different shot width between different energy bands. The shot width defined from the auto-correlation function of shot profile does not show a bimodal distribution.