Supplementary material for PhD thesis "SPH simulations of X-ray binary systems" - 1/4: 2d 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.

本数据集囊括了2006年提交论文时所附载于光盘上的文件。为保障数据的长久保存，该数据集于2024年上传至ORDO。欲获取详细信息，请参阅基于ORO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中吸积物质。此类系统中吸积盘的物理机制目前是国际研究的热点。特别是，超级计算的出现使得对这类系统动力学的定量数值研究成为可能。数值模拟正日益能够再现观测到的现象，而模拟与观测之间的相互作用正不断精炼对这些系统进行解析研究所得到的图景。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/三维平滑粒子流体动力学（SPH）模拟，揭示了形状、运动学和耗散不断变化的复杂吸积盘。流-盘碰撞区域和盘螺旋密度波是能量耗散的显著来源。对于极端质量比，耗散的能量在超级周期上呈现调制现象。我们生成了合成拖尾光谱图，揭示了由流气体和盘气体在流-盘碰撞冲击处产生的两个明显的S波特征。这些S波非正弦波，并随盘进动相位演变。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、光学上厚的吸积盘被中央辐射源照亮。这种照明对盘面施加非轴对称辐射压力，从而在盘上产生扭矩，使盘产生扭曲或变形。初始平面盘对由辐射扭矩驱动的扭曲表现出不稳定性，并且一般来说，扭曲也相对于轨道流动以逆行方向进动。我们使用多种不同的亮度模拟了多个具有不同质量比的X射线双星系统。Her X-1和SS 433等X射线双星系统的模型能够再现其观测到的长周期光变振幅。