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arXiv 2007.05526astro-ph.HEgr-qcnucl-th
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GW190814:伴中子星的自旋和状态方程

GW190814: Spin and equation of state of a neutron star companion

Antonios Tsokaros, Milton Ruiz, Stuart L. Shapiro

摘要:

LIGO/Virgo最近发现了一个合并的双星系统,它有一个$\sim 23 M_\odot$黑洞和一个$\sim 2.6 M_\odot$紧凑的伴星,这引发了一场关于次级黑洞性质的争论,它落入了所谓的质量间隙。在这里,我们探讨的假设,次级是一个中子星(NS)的一些后果。我们表明,迄今可行的状态方程(EOSs),快速均匀旋转的具体例子可能既不是必要的一些EOSs,也不足以为其他解释存在的NS。从GW 170817得到的球形NS最大质量的绝对上限已经表明,这个未知的致密伴星可能是一个缓慢甚至不旋转的NS。然而,GW 170817所青睐的几个具有最大球形质量$\lesssim 2.1 M_\odot$的软NS EOS不能用来解释这个物体,即使允许最大均匀旋转。相比之下,足够坚硬的EOS产生缓慢旋转或在某些情况下不旋转的$2.6 M_\odot$ NS,并且与GW 170817和NICER的结果兼容,可以解释黑洞伴星。

英文摘要:

The recent discovery by LIGO/Virgo of a merging binary having a $\sim 23 M_\odot$ black hole and a $\sim 2.6 M_\odot$ compact companion has triggered a debate regarding the nature of the secondary, which falls into the so-called mass gap. Here we explore some consequences of the assumption that the secondary was a neutron star (NS). We show with concrete examples of heretofore viable equations of state (EOSs) that rapid uniform rotation may neither be necessary for some EOSs nor sufficient for others to explain the presence of a NS. Absolute upper limits for the maximum mass of a spherical NS derived from GW170817 already suggest that this unknown compact companion might be a slowly or even a nonrotating NS. However several soft NS EOSs favored by GW170817 with maximum spherical masses $\lesssim 2.1 M_\odot$ cannot be invoked to explain this object, even allowing for maximum uniform rotation. By contrast, sufficiently stiff EOSs that yield $2.6 M_\odot$ NSs which are slowly rotating or, in some cases, nonrotating, and are compatible with GW170817 and the results of NICER, can account for the black hole companion.

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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