KMS of Xinjiang Astronomical Observatory, CAS
| 中子星X 射线双星GX 349+2 交叉相关分析 | |
| Alternative Title | The cross-correlation analysis of Neutron Star X-ray Binaries GX 349+2 |
张文雅
| |
| Subtype | 硕士 |
| Thesis Advisor | 丁国强 |
| 2015 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 中国科学院新疆天文台 |
| Degree Discipline | 理学 |
| Keyword | x 射线双星 时延 Gx 349+2 吸积盘 |
| Abstract | 致密天体是恒星演化的终结产物，可以单独存在，也可以和另外一个恒星组成双星系统。在X 射线双星系统中，致密星通过吸积的方式获取伴星的物质，并辐射X 射线。能谱和时变的分析是研究X 射线双星的两种主要手段，在时变分析中，交叉相关分析法被用来研究不同能段的光变曲线之间的关系。通过分析不同能段间光变曲线的交叉相关函数，可以得到高、低能光变曲线间时间延迟和相关性，这有利于研究吸积盘的结构和X 射线双星的物理机制。 本文使用罗西X 射线时变探测器（Rossi X-ray Timing Explorer，RXTE）对中子星X 射线双星GX 349+2 的观测数据，系统分析了其高、低能光变曲线交叉相关性。GX 349+2 在1998 年1 月1 日至1 月29 日这段观测时间里，在其强度硬度图（Hardness-Intensity Diagram, HID）上展现出完整的Z 形轨迹，我们对其交叉相关性沿HID 图轨迹的演化做了系统的分析。在HID 多数区域我们探测到了正相关和正相关的时延。不在HID 上观测号中，8%的观测号是反相关，正相关占了87%，我们发现反相关的时延尺度远大于正相关时延尺度，这表明这两种类型的时延产生物理机制有很大的不同。经过分析，我们发现过去解释短时标时延模型和截断吸积盘模型都不能解释中子星X 射线双星中的长时标时延。我们认为延展的吸积盘冕的模型可以用来解释中子星X 射线双星中的长时标时延。 |
| Other Abstract | Compact objects, including white dwarfs, neutron stars, and black holes, are the outcomes of stellar evolution. A compact object and a star can compose a X-ray binary. In X-ray binaries, the compact objects attract matter from their companion stars and, thus, X-rays are emitted.The spectral and timing analysis are two main methods for studying X-ray binaries. Among the timing analyses, the cross-correlation analysis can be used to study the relation of light curves in different energy bands. By analyzing the cross-correlation function of light curves in the different energy bands, the correlations and time lags between soft and hard X-ray light curves can be obtained, which are useful and important to investigate the structures of accretion disk and the mechanisms for producing X-rays. Using all the observations from RXTE for Z source GX 349+2, we systematically carry out cross-correlation analysis between its soft and hard X-ray light curves. During the observations from January 1, 1998 to January 29, 1998, GX 349+2 traced out the most extensive Z track on its hardness-intensity diagram, we study the cross-correlation evolution along the Z track of GX 349+2. The positive correlations and positively correlated time lags are detected throughout the Z track. Outsidethe Z track, anti-correlations and anti-correlated time lags are found, but the anti-correlated time lags are much longer than the positively correlated time lags, which might indicate different mechanisms for producing the two types of time lags. We argue that neither the short-term time lag models nor the truncated accretion disk model can account for the long-term time lags in neutron star X-ray binaries (NSXBs). We suggest that the extended accretion disk corona model could be an alternative model to explain the long-term time lags detected in NSXBs. |
| Subject Area | 天体物理 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/652 |
| Collection | 研究生学位论文 射电天文研究室 |
| Recommended Citation GB/T 7714 | 张文雅. 中子星X 射线双星GX 349+2 交叉相关分析[D]. 中国科学院新疆天文台. 中国科学院大学,2015. |
| Files in This Item: | ||||||
| File Name/Size | DocType | Version | Access | License | ||
| 学位论文-张文雅.pdf（2323KB） | 暂不开放 | CC BY-NC-ND | Application Full Text | |||
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