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arXiv 1908.05150astro-ph.HE
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暗物质混合白矮星的吸积诱导坍缩-- II:自转和引力波信号

Accretion-Induced Collapse of Dark Matter Admixed White Dwarfs -- II: Rotation and Gravitational-wave Signals

Shuai Zha, Ming-Chung Chu, Shing-Chi Leung, Lap-Ming Lin

摘要:

利用轴对称流体动力学方法模拟了暗物质与旋转白矮星的吸积诱导坍缩及其引力波爆发信号。对于中心重子密度相同的初始WD模型,发现混合DM延迟了AIC的坍落和反弹阶段,并降低了产生的原中子星(PNS)的中心密度和质量。反弹时间,中心密度和PNS质量通常取决于两个参数,混合DM质量$M_\mathrm{DM}$和反弹时内核的旋转动能和引力能之间的比率$β_\mathrm{ic,b}$。所发射的GWs具有一般的波形形状,其幅度的变化$h_+$在$β_\mathrm{ic,b}$和$M_\mathrm{DM}$上显示出简并性。我们发现,反弹周围的GW振幅峰值之间的比率允许打破$β_\mathrm{ic,b}$和$M_\mathrm{DM}$两者的简并和提取。即使在核物质状态方程的不确定性范围内,如果DM核的质量大于0.03 $M_{\odot}$,也可以推断出DM核。我们还讨论了可能的DM对PNS g模振荡发出的GW信号的影响。GW可以提高AIC的检测可能性,以及打开一个新的窗口,在DM的间接检测。

英文摘要:

We present axisymmetric hydrodynamical simulations of accretion-induced collapse (AIC) of dark matter (DM) admixed rotating white dwarfs (WD) and their burst gravitational-wave (GW) signals. For initial WD models with the same central baryon density, the admixed DM is found to delay the plunge and bounce phases of AIC, and decrease the central density and mass of the proto-neutron star (PNS) produced. The bounce time, central density and PNS mass generally depend on two parameters, the admixed DM mass $M_\mathrm{DM}$ and the ratio between the rotational kinetic and gravitational energies of the inner core at bounce $β_\mathrm{ic,b}$. The emitted GWs have generic waveform shapes and the variation of their amplitudes $h_+$ show a degeneracy on $β_\mathrm{ic,b}$ and $M_\mathrm{DM}$. We found that the ratios between the GW amplitude peaks around bounce allow breaking the degeneracy and extraction of both $β_\mathrm{ic,b}$ and $M_\mathrm{DM}$. Even within the uncertainties of nuclear matter equation of state, a DM core can be inferred if its mass is greater than 0.03 $M_{\odot}$. We also discuss possible DM effects on the GW signals emitted by PNS g-mode oscillations. GW may boost the possibility for the detection of AIC, as well as open a new window in the indirect detection of DM.

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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