Supplementary material for PhD thesis "SPH simulations of X-ray binary systems" -4/4: warped disc movies

This dataset comprises the files contained on a CD-ROM which was attached to the thesis when it was submitted in 2006. It was uploaded to ORDO in 2024 for preservation purposes. For more information, please refer to the thesis SPH simulations of X-ray binary systems via ORO.Thesis abstractIn low mass X-ray binaries a neutron star or a black hole accretes from a low mass companion star via an accretion disc. The physics of accretion discs in these systems is currently an area of vigorous international research activity. In particular the advent of supercomputing has allowed quantitative numerical work on the dynamics of such systems. The numerical simulations are becoming increasingly able to reproduce observed phenomena, and the interplay between simulation and observation is refining the picture derived from analytical work on these systems. Consequently this PhD exploits the synergy between observation and simulation. We present two/three-dimensional smoothed particle hydrodynamics (SPH) simulations of a number of binary systems, such as XTE J1118+480, and reveal complex accretion discs that are continuously varying in shape, kinematics and dissipation. The stream-disc impact region and disc spiral density waves are prominent sources of energy dissipation. For extreme mass ratios the dissipated energy is modulated on the superhump period. We generate synthetic trailed spectrograms that reveal two distinct `S-wave' features, produced by the stream gas and the disc gas at the stream-disc impact shock. These S-waves are non-sinusoidal, and evolve with disc precession phase. We also describe three-dimensional SPH calculations of warped accretion discs in X-ray binary systems. Geometrically thin, optically thick accretion discs are illuminated by a central radiation source. This illumination exerts a non-axisymmetric radiation pressure on the surface of the disc resulting in a torque that acts on the disc to induce a twist or warp. Initially planar discs are shown to be unstable to warping driven by the radiation torque and in general the warps also precess in a retrograde direction relative to the orbital flow. We simulate a number of X-ray binary systems which have different mass ratios using a number of different luminosities for each. Models for X-ray binary systems such as Her X-1 and SS 433 are able to reproduce their observed long period photometric modulations.

本数据集包含2006年提交论文时所附CD-ROM中的文件。为便于保存，该数据集于2024年上传至ORDO平台。欲获取更多信息，请参阅关于通过ORO进行X射线双星系统SPH模拟的论文摘要。在低质量X射线双星系统中，中子星或黑洞通过吸积盘从低质量伴星吸积物质。此类系统吸积盘的物理机制目前是国际研究的热点。特别是，超级计算技术的出现，使得对这类系统动力学进行定量数值研究成为可能。数值模拟在日益精确地再现观测现象，而模拟与观测之间的相互作用正不断丰富着对这些系统分析工作的认识。因此，本研究充分利用了观测与模拟之间的协同效应。我们展示了多个双星系统（如XTE J1118+480）的二维/三维光滑粒子流体动力学（SPH）模拟，揭示了形状、动力学和耗散持续变化的复杂吸积盘。流体-盘面冲击区域和盘面螺旋密度波是能量耗散的重要来源。对于极端质量比，耗散能量以超周期振荡的方式调制。我们生成了合成拖尾光谱图，揭示了由流体气体和盘面气体在流体-盘面冲击激波处产生的两个明显的S波特征。这些S波非正弦波，并随盘面进动相位演化。此外，我们还描述了X射线双星系统中扭曲吸积盘的三维SPH计算。几何上薄的、光学的厚的吸积盘受到中央辐射源的照明。这种照明对盘面施加非轴对称辐射压力，从而在盘面上产生一个扭矩，该扭矩作用于盘面，引起盘面的扭曲或变形。最初平面盘在辐射扭矩驱动的扭曲作用下是不稳定的，一般来说，扭曲也相对于轨道流动以逆行方向进动。我们使用不同的亮度对多个不同质量比的双星系统进行模拟，并能够再现如Her X-1和SS 433等X射线双星系统的观测长期光度调制。