论文标题
在白色矮人和中子星二进制中的非球形增生剂上的对流增生：一种新的冲击形成情况
Advective accretion onto a non-spherical accretor in white dwarf and neutron star binaries: a new scenario of shock formation
论文作者
论文摘要
大量有关围绕紧凑型物体（例如，白色矮人（WD），中子星（NS）或黑洞（BH））的开普勒式流体动力学以及亚雄性积聚盘的大量研究。虽然，当紧凑的物体（例如WD或NS）具有有限的表面时，其快速旋转时，恒星磁场可能会导致球形对称性的变形。较早的开普勒盘研究表明，与紧凑型物体的球形对称性偏离可能会在高频下影响观察到的光曲线和光谱。在这里，我们探索了紧凑型物体非球体性质对光学薄，几何厚的亚菌水对流流的水动力学的影响。我们发现，由于中央增生器的非球形形状，有可能在靠近增生器的亚菌流流中触发兰肯 - 霍尼奥特休克，而无需考虑任何一般的相对论效应或恒星硬表面的存在。我们的结果与在WD上的积聚更相关，因为图片中几乎没有任何一般的相对论效应。 We propose that some observational features e.g., high significance of fitting the spectra with multi-temperature plasma models rather than single temperature models, and variable efficiency of X-ray emission (X-ray luminosity in comparison with optical and UV luminosity of the disk) in nonmagnetic cataclysmic variables can be explained by the presence of a shock in the sub-Keplerian advective flow.
Numerous studies on hydrodynamics of the Keplerian as well as the sub-Keplerian accretion disc around a compact object (e.g., white dwarf (WD), neutron star (NS), or a black hole (BH)) attempted to explain the observed UV, soft and hard X-ray spectra. Although, when the compact object (e.g., a WD or an NS) has a finite surface, its rapid rotation, the stellar magnetic field could cause deformation of the spherical symmetry. Earlier studies for Keplerian disc showed that a deviation from the spherical symmetry of the compact object could affect the observed light curve and spectra at high frequencies. Here, we have explored the effect of the non-spherical nature of a compact object on the hydrodynamics of an optically thin, geometrically thick sub-Keplerian advective flow. We find that due to non-spherical shape of the central accretor, there is a possibility to trigger Rankine-Hugoniot shock in the sub-Keplerian advective flow close to the accretor without considering any general relativistic effect or presence of the hard surface of the star. Our results are more relevant for accretion onto WD as hardly any general relativistic effect will come in the picture. We propose that some observational features e.g., high significance of fitting the spectra with multi-temperature plasma models rather than single temperature models, and variable efficiency of X-ray emission (X-ray luminosity in comparison with optical and UV luminosity of the disk) in nonmagnetic cataclysmic variables can be explained by the presence of a shock in the sub-Keplerian advective flow.
