标题： Ia型超新星的多样性源于对称破缺 显示英文标题

标题： The Diversity of Type Ia Supernovae from Broken Symmetries

摘要： Ia型超新星爆发于双星系统中的碳氧白矮星从伴星吸积质量，达到临界质量后爆炸。它们光变曲线的近似均匀性使这些超新星成为测量宇宙膨胀的良好标准烛光，但必须加以校正以考虑更亮的超新星具有更宽光变曲线的事实。在一维建模中，通过选择特定参数可以重现亮度-宽度关系的一般趋势，但最近研究表明点火和引爆过程本质上是不对称的。我们在此报告了多维建模的爆炸物理和辐射转移，揭示了球对称性的破坏是决定亮度-宽度关系及其周围观测散射的关键因素。偏离球对称性也可以解释某些超新星光度中检测到的有限偏振。亮度-宽度关系的斜率和归一化值对白矮星前身天体的一些性质（特别是碳和氧以外元素的痕量丰度）有较弱的依赖性。未能对此效应进行校正可能导致对遥远超新星距离的系统高估达2%。 显示英文摘要

摘要： Type Ia supernovae result when carbon-oxygen white dwarfs in binary systems accrete mass from companion stars, reach a critical mass, and explode. The near uniformity of their light curves makes these supernovae good standard candles for measuring cosmic expansion, but a correction must be applied to account for the fact that the brighter supernovae have broader light curves. One-dimensional modelling, with a certain choice of parameters, can reproduce this general trend in the width-luminosity relation, but the processes of ignition and detonation have recently been shown to be intrinsically asymmetric. Here we report on multi-dimensional modelling of the explosion physics and radiative transfer that reveals that the breaking of spherical symmetry is a critical factor in determining both the width luminosity relation and the observed scatter about it. The deviation from sphericity can also explain the finite polarization detected in the light from some supernovae. The slope and normalization of the width-luminosity relation has a weak dependence on certain properties of the white dwarf progenitor, in particular the trace abundances of elements other than carbon and oxygen. Failing to correct for this effect could lead to systematic overestimates of up to 2% in the distance to remote supernovae.