标题： 一个处于特殊双星系统中的超大质量快速自转白矮星 显示英文标题

标题： An ultra-massive fast-spinning white dwarf in a peculiar binary system

摘要： 白矮星的质量通常集中在约 0.6 倍太阳质量（M⊙）的一个狭窄范围内。仅有少数超大质量白矮星（M > 1.2 M⊙）被发现。那些位于双星系统中的白矮星尤其值得关注，因为少量吸积的质量就可能使它们超过钱德拉塞卡极限，在此极限之外它们会变得引力不稳定。利用 XMM-Newton 卫星的数据，我们仅基于动力学测量表明，X 射线脉动源 RX J0648.0-4418 是一个质量 > 1.2 M⊙ 的白矮星。这个位于后公共包层双星系统中的超大质量白矮星，与一颗热亚矮星伴星一起，当其富氦的伴星以增加的速率通过洛希瓣溢出转移质量时，可能达到钱德拉塞卡极限，并有可能作为 Ia 型超新星爆发。 显示英文摘要

摘要： White dwarfs typically have masses in a narrow range centered at about 0.6 solar masses (Msun). Only a few ultra-massive white dwarfs (M>1.2 Msun) are known. Those in binary systems are of particular interest because a small amount of accreted mass could drive them above the Chandrasekhar limit, beyond which they become gravitationally unstable. Using data from the XMM-Newton satellite, we show that the X-ray pulsator RX J0648.0-4418 is a white dwarf with mass > 1.2 Msun, based only on dynamical measurements. This ultra-massive white dwarf in a post-common envelope binary with a hot subdwarf can reach the Chandrasekhar limit, and possibly explode as a Type Ia supernova, when its helium-rich companion will transfer mass at an increased rate through Roche lobe overflow.