arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1109.3402astro-ph.HEgr-qc
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从黑洞-中子星合并中提取状态方程参数。I.非旋转黑洞

Extracting equation of state parameters from black hole-neutron star mergers. I. Nonspinning black holes

Benjamin D. Lackey, Koutarou Kyutoku, Masaru Shibata, Patrick R. Brady, John L. Friedman

摘要:

黑洞-中子星(BHNS)系统的晚期螺旋、合并和衰荡可以提供有关中子星状态方程(EOS)的信息。候选EOS可以近似为一个参数化的分段多变EOS以上的核密度,匹配到一个固定的低密度EOS,我们报告的结果从一个大的BHNS螺旋模拟系统地改变两个参数。为了在模拟的准确性,我们发现,除了中子星质量,一个单一的物理参数λ,描述其变形性,可以提取从后期的螺旋,合并,和振铃波形。这个参数与中子星的半径、质量和l=2勒夫数k_2的关系为λ = 2 k_2 R^5/3 M_{NS} ^[5],它也是决定在早期螺旋中偏离点粒子动力学的参数。因此,从BHNS螺旋观测到的引力波将状态方程限制在参数空间中常数λ的表面上,并因测量误差而变厚。使用单个高级LIGO探测器的各种配置,我们发现中子星可以与相同质量的黑洞区分开来,并且在距离为100 Mpc的质量比为Q=2和3的单个事件中可以以10-40%的精度提取λ ^{1/5}或等效R,而使用拟议的爱因斯坦望远镜,EOS参数的提取精度可以提高一个数量级。

英文摘要:

The late inspiral, merger, and ringdown of a black hole-neutron star (BHNS) system can provide information about the neutron-star equation of state (EOS). Candidate EOSs can be approximated by a parametrized piecewise-polytropic EOS above nuclear density, matched to a fixed low-density EOS; and we report results from a large set of BHNS inspiral simulations that systematically vary two parameters. To within the accuracy of the simulations, we find that, apart from the neutron-star mass, a single physical parameter Lambda, describing its deformability, can be extracted from the late inspiral, merger, and ringdown waveform. This parameter is related to the radius, mass, and l=2 Love number, k_2, of the neutron star by Lambda = 2k_2 R^5/3M_{NS}^5, and it is the same parameter that determines the departure from point-particle dynamics during the early inspiral. Observations of gravitational waves from BHNS inspiral thus restrict the EOS to a surface of constant Lambda in the parameter space, thickened by the measurement error. Using various configurations of a single Advanced LIGO detector, we find that neutron stars are distinguishable from black holes of the same mass and that Lambda^{1/5} or equivalently R can be extracted to 10-40% accuracy from single events for mass ratios of Q=2 and 3 at a distance of 100 Mpc, while with the proposed Einstein Telescope, EOS parameters can be extracted to accuracy an order of magnitude better.

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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