arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2003.00693astro-ph.HE
收藏

燃烧中子星到夸克星相变的引力波特征

Gravitational wave signature from phase transition of a combusting neutron star to quark star

Ritam Mallick, Shailendra Singh, R Prasad

摘要:

在中子星中心的涨落产生了一个非常接近恒星中心的小的退禁闭夸克核。夸克-强子边界的密度不连续性引发了一个冲击波,它向恒星外传播。冲击波有足够的能量将恒星中的核物质燃烧成2味夸克物质。在弱相互作用时间尺度上,2味夸克物质是不稳定的,并沉降到稳定的3味夸克物质。本文研究了二味物质向三味物质的转化。我们建立了一个微分方程,把多余的下夸克转化为奇异夸克,其中涉及到夸克的弱反应和扩散。计算反应速率,我们求解微分方程以找到转化前沿的速度。当转换前沿向外移动时,密度分布发生变化,导致恒星的四极矩发生变化,从而发射出引力波。我们发现GW信号强烈依赖于恒星的温度和质量。较冷恒星的GW振幅在目前的探测器能力范围内,但频率略高。相对较热的恒星位于现有探测器的边界上,很容易被未来的探测器探测到,它们的频率也在目前的探测范围内。相比之下,来自银河系彗星的PT很容易用现有的探测器探测到。

英文摘要:

Fluctuation at the neutron star center gives rise to a small deconfined quark core very close to the star center. The density discontinuity at the quark-hadron boundary initiates a shock wave, which propagates outwards of the star. The shock has enough energy to combust nuclear matter to 2-flavor quark matter in the star. The 2-flavor quark matter is not stable and settles to a stable 3-flavor matter in the weakly interacting timescale. In this paper, we study the conversion of 2-flavor matter to 3-flavor matter. We set up a differential equation to convert the excess of down quarks to strange quarks involving weak reaction and diffusion of quarks. Calculating the reaction rate, we solve the differential equation to find the velocity of the conversion front. As the conversion front moves out, the density profile changes, bringing about a change in the star's quadrupole moment and thereby emitting gravitational waves. We find that the GW signal depends strongly on the star temperature and mass. The GW amplitude of a colder star is well within present detector capability, but the frequency is slightly on the higher side. Relatively hotter stars are on the boundary of present detectors and easily detectable with future detectors, and their frequency is also within the present detectability range. In comparison, PT from galactic pulsars is easily detectable with present detectors.

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。

↑