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arXiv 0803.1334astro-ph
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形成亚毫秒脉冲的两种可能途径

Two possible approaches to form sub-millisecond pulsars

Yuanjie Du, R. X. Xu, G. J. Qiao, J. L. Han

摘要:

脉冲星被认为是正常的中子星或夸克星。亚毫秒级的中子星如果被探测到,将在区分夸克星和中子星方面发挥重要作用。一个关键问题是亚毫秒级的恒星是如何形成的。本文讨论了亚开普勒情形(中子星和夸克星)和超开普勒情形(夸克星受强相互作用约束),以探讨形成亚毫秒双星的可能途径。在次开普勒的情况下,中子星和夸克星的平衡周期都可以低至~0.4毫秒,当它们通过吸积在双星系统中旋转时。在超开普勒的情况下,如果不同质量的夸克星可以从白矮星的吸积诱导坍缩(AIC)中形成,那么夸克星的初始周期很可能为0.1 ms。由于引力波辐射的存在,亚毫秒脉冲星保持周期<1 ms的时间尺度受到限制。我们发现中子星在亚毫秒周期内的时间尺度约为10年,但对于低质量夸克星估计的时间尺度(> 1000万年)可能足够长,我们可以检测到。

英文摘要:

Pulsars have been recognized as normal neutron stars or quark stars. Sub-millisecond pulsars, if detected, would play an essential and important role in distinguishing quark stars from neutron stars. A key question is how sub-millisecond pulsars could form. Both sub-Keplerian (for neutron and quark stars) and super-Keplerian cases (only for quark stars, which are bound additionally by strong interaction) have been discussed in this paper in order to investigate possible ways of forming sub-millisecond pulsars. In the sub-Keplerian case, the equilibrium periods of both neutron and quark stars could be as low as ~0.4 ms when they are spun up through accretion in binary systems. In the super-Keplerian case, pulsars could very likely have an initial period of ~0.1 ms if quark stars with different mass could be formed from accretion-induced collapse (AIC) of white dwarfs. The timescale for a sub-millisecond pulsar to keep its period <1 ms is restricted due to gravitational wave radiation. We found that the timescales of neutron stars within sub-millisecond periods are approximately ~10 yr, but the timescales estimated (>10 Myr) for low-mass quark stars could be long enough for us to detect.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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