标题： Ia型超新星中的不完全碳氧爆炸 显示英文标题

标题： Incomplete carbon-oxygen detonation in Type Ia supernovae

摘要： 在白矮星以Ia型超新星（SNIa）爆炸的低密度外层中，可能发生的不完全碳-氧爆轰，在领先12C + 12C反应（C-爆轰）中燃烧12C后反应终止。 先前对低密度下碳-氧爆轰结构和稳定性的研究是基于“爆轰波”的“速度”来自于碳和氧完全燃烧成铁的假设。 实际上，在密度<10^6 g/cm3时，SNIa中的爆轰可能释放的能量不到可用核能的一半。 在本文中我们研究了这种爆轰的基本特性。 我们发现，无支撑的稳态C-爆轰的长度是之前估计的30-100倍，并且减少的能量对爆轰稳定性有显著影响。 与完全爆轰不同，完全爆轰是一维稳定的，而C-爆轰可能是一维不稳定的，并通过自发燃烧周期性地重新点燃自身来传播。 在rho < 10^6 g/cm3时的重新点燃周期估计大于SNIa爆炸的时间尺度。 这表明，在这些密度下C-爆轰的传播和熄灭可能受到不稳定性的影响。 讨论了这种效应的潜在观测意义。 显示英文摘要

摘要： Incomplete carbon-oxygen detonation with reactions terminating after burning of 12C in the leading 12C + 12C reaction (C-detonation) may occur in the low density outer layers of white dwarfs exploding as Type Ia supernovae (SNIa). Previous studies of carbon-oxygen detonation structure and stability at low densities were performed under the assumption that the "velocity" of a detonation wave derives from complete burning of carbon and oxygen to iron. In fact, at densities <10^6 g/cm3 the detonation in SNIa may release less than a half of the available nuclear energy. In this paper we study basic properties of such detonations. We find that the length of an unsupported steady-state C-detonation is 30-100 times greater than previously estimated, and that the decreased energy has a drastic effect on the detonation stability. In contrast to complete detonations which are one-dimensionally stable, C-detonations may be one-dimensionally unstable and propagate by periodically re-igniting themselves via spontaneous burning. The re-ignition period at rho < 10^6 g/cm3 is estimated to be greater than the time-scale of a SNIa explosion. This suggests that propagation and quenching of C-detonations at these densities could be affected by the instability. Potential observational implications of this effect are discussed.