g -mode oscillations in hybrid stars: A tale of two sounds
g -mode oscillations in hybrid stars: A tale of two sounds
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DOI：
10.1103/physrevd.103.123009
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发表时间：
2021-01
期刊：
影响因子：
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通讯作者：
P. Jaikumar;A. Semposki;M. Prakash;C. Constantinou
中科院分区：
文献类型：
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作者：
P. Jaikumar;A. Semposki;M. Prakash;C. Constantinou
我们研究了含有夸克物质的混合恒星的主核心g模振荡，发现它们与相同质量的普通中子星或自束缚夸克恒星相比，具有异常大的频率范围（≈200 600 Hz）。提供了理论论据和数值计算，将这种影响追溯到夸克和核子混合相中平衡和绝热声速行为的差异。我们提出，核心g模振荡对中子星中非核物质的敏感性可能是由于混合夸克-核子相的存在。根据我们的分析，我们得出结论，对于双星合并，其中一个或两个组成部分可能是混合星，在混合星中泵入共振g模式的潮汐能的比例可以超过正常中子星的2-3倍，尽管共振发生在吸气的最后阶段。另一方面，自束缚恒星与g模的潮汐重叠要弱得多。混合星的累积潮汐相位误差∆φ ~ = 0.5 rad与普通中子星的潮汐相误差相当，这给区分这两种情况带来了挑战。然而，如果主g模被激发到足够的振幅，可以在内部有夸克物质的合并后残余物中检测到，那么它的频率将可能是中子星中存在非核物质的指示。
We study the principal core g-mode oscillation in hybrid stars containing quark matter and find that they have an unusually large frequency range (≈ 200 600 Hz) compared to ordinary neutron stars or self-bound quark stars of the same mass. Theoretical arguments and numerical calculations that trace this effect to the difference in the behaviour of the equilibrium and adiabatic sound speeds in the mixed phase of quarks and nucleons are provided. We propose that the sensitivity of core g-mode oscillations to non-nucleonic matter in neutron stars could be due to the presence of a mixed quark-nucleon phase. Based on our analysis, we conclude that for binary mergers where one or both components may be a hybrid star, the fraction of tidal energy pumped into resonant g-modes in hybrid stars can exceed that of a normal neutron star by a factor of 2-3, although resonance occurs during the last stages of inspiral. A self-bound star, on the other hand, has a much weaker tidal overlap with the g-mode. The cumulative tidal phase error in hybrid stars, ∆φ ∼= 0.5 rad, is comparable to that from tides in ordinary neutron stars, presenting a challenge in distinguishing between the two cases. However, should the principal g-mode be excited to sufficient amplitude for detection in a postmerger remnant with quark matter in its interior, its frequency would be a possible indication for the existence of non-nucleonic matter in neutron stars.