KMS of Xinjiang Astronomical Observatory, CAS
| 中子星低质量X射线双星天蝎座X-1硬X射线辐射研究 | |
| Alternative Title | Hard X-ray study of neutron star low mass X-ray binary Scorpius X-1 |
陈婷婷
| |
| Subtype | 硕士 |
| Thesis Advisor | 丁国强 |
| 2020 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Name | 理学硕士 |
| Degree Discipline | 天体物理 |
| Keyword | 中子星 X 射线双星 Scorpius X-1 |
| Abstract | 中子星低质量X射线双星（NS-LMXB）系统由一个弱磁场、快速旋转的中子星（NS）和一个低质量恒星伴星组成。NS-LMXBs系统中，伴星通过洛希瓣溢出将物质转移到致密星上。硬X射线辐射在黑洞X射线双星中很常见，但在NS-LMXBs中很少见。对 NS-LMXBs 硬X射线辐射的研究一直是高能天体物理领域的一个研究课题。 本学位论文利用在1996年2月至2012年1月期间X射线天文卫星罗西X射线时变探索者上搭载的高能X射线时变实验室（HEXTE）观测天蝎座X-1（Sco X-1）的所有数据，系统地寻找该源在20-220 keV能量范围的硬X射线能谱中存在硬X射线幂律尾巴，并结合正比计数器阵列（PCA）的数据，研究硬X射线尾巴沿其硬度-强度图（HID）中Z型轨迹演化。发现在30个观测能谱中存在硬 X 射线尾巴，且它的出现并不局限于HID上的特定位置。但总体来看硬 X 射线尾 巴在水平分支(HB)和正常分支(NB)上出现频繁，在耀斑分支(FB)上却很少见。能谱分析表明，当源沿 HB→NB→FB 序列变化时，硬X射线尾巴变硬，且其流量减小。在3-220 keV能量范围内，通过联合拟合了PCA+HEXTE的能谱，发现吸积流的团块康普顿化 (BMC) 是产生该源的 HB 和 NB 硬 X 射线尾巴的一种可能机制。 BMC过程的种子光子的温度分布在∼（2.4-2.6）keV范围内，这表明种子光子可能来自中子星表面或边界层，因此，BMC 过程可能发生在中子星周围或边界层。FB 上的硬 X 射线尾巴与HB和 NB上的有很大的不同，这意味着FB上的硬X射线尾巴的产生机制可能是不同的，给出了一些 FB上产生硬 X 射线尾巴的可能机制。 |
| Other Abstract | The neutron star low-mass X-ray binary (NS-LMXB) consists of a weakly magnetized and fast rotating neutron star (NS) and a low-mass star as its companion. In NS-LMXBs, the mass accretion onto the compact star is performed via Roche-lobe overflow. The hard X-ray emission has been commonly observed in black hole X-ray binaries, but uncommonly in NS-LMXBs. The study of hard X-ray emission in NS-LMXBs has been a subject in high-energy astrophysics.In this paper, using all the data of the High Energy X-ray Timing Experiment (HEXTE) on board the Rossi X-ray Timing Explorer for Sco X-1 from 1996 February to 2012 January, we systematically search for hard X-ray tails in the X-ray spectra in 20-220 keV and together with the data of the Proportional Counter Array (PCA) investigate the evolution of the detected hard X-ray tails along the Z track on its hardness-intensity diagram (HID). The hard X-ray tails are detected in 30 observations and their presence is not confined to a specific position on the HID. The hard X-ray tails are present frequently on the horizontal branch (HB) and the normal branch (NB) and, however, uncommonly on the flaring branch (FB). Our analysis suggests that in the sequence HB→NB→FB on the HID the hard X-ray tails becomes hard and its flux decreases. Jointly fitting the PCA+HEXTE spectra in 3-220 keV, it is found that the Bulk-Motion Comptonization (BMC) could be an alternative mechanism for producing the hard X-ray tails on the HB and the NB of this source. The temperature of the seed photon for the BMC spans in the range of ∼ (2.4-2.6) keV, indicating that the seed photons might come from the surface of the neutron star (NS) or the boundary layer and, therefore, the BMC process could take place around the NS or in the boundary layer. The hard X-ray tails on the FB differ from those on the HB and the NB very much, implying that the mechanisms of the hard X-ray tails of the FB could be different. Some possible mechanisms for producing the hard X-ray tails on the FB are given. |
| Pages | 50 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xao.ac.cn/handle/45760611-7/4137 |
| Collection | 研究生学位论文 |
| Affiliation | 中国科学院新疆天文台 |
| First Author Affilication | Xinjiang Astronomical Observatory, Chinese Academy of Sciences |
| Recommended Citation GB/T 7714 | 陈婷婷. 中子星低质量X射线双星天蝎座X-1硬X射线辐射研究[D]. 北京. 中国科学院大学,2020. |
| Files in This Item: | ||||||
| File Name/Size | DocType | Version | Access | License | ||
| 陈婷婷.pdf（13851KB） | 学位论文 | 暂不开放 | CC BY-NC-SA | Application Full Text | ||
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