arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1008.3013astro-ph.HEastro-ph.SRcond-mat.supr-con
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超流毫秒星系中的长周期热振荡

Long-period thermal oscillations in superfluid millisecond pulsars

Cristobal Petrovich, Andreas Reisenegger

摘要:

在以前的论文中,我们已经证明,当中子星的旋转速度减慢时,由于粒子混合物的逐渐变化,它的内部会被加热(旋转化学加热)。在以前研究的情况下(非超流中子星或只有修改Urca反应的超流星),这导致了一个准稳态,其中恒星辐射热光子很长一段时间,可能解释了从毫秒脉冲星J 0437 -4715观察到的紫外线辐射。第一次,我们探讨了旋转化学加热与直接Urca反应和均匀和各向同性的超流能隙的不同大小的现象。我们首先做探索性的工作,通过整合的热和化学演化方程数值不同的能隙,揭示了丰富的现象学的稳定和不稳定的解决方案。为了理解这些,我们围绕准稳态进行稳定性分析,确定增长,衰减和振荡解决方案的特征时间。对于小的差距,现象是类似于以前研究的情况下,在这个意义上说,解决方案迅速收敛到一个准稳态。对于大的能隙($\gtrsim 0.05$ MeV),这些解变得不稳定,导致周期性的极限环行为($\sim 10^{6-7} yr, in which the star is hot ($ T_s \gtrsim 10^5 $ K) for a small fraction of the cycle ($ \sim 5- 20%$),并且冷的时间更长。

英文摘要:

In previous papers, we have shown that, as the rotation of a neutron star slows down, it will be internally heated as a consequence of the progressively changing mix of particles (rotochemical heating). In previously studied cases (non-superfluid neutron stars or superfluid stars with only modified Urca reactions), this leads to a quasi-steady state in which the star radiates thermal photons for a long time, possibly accounting for the ultraviolet radiation observed from the millisecond pulsar J0437-4715. For the first time, we explore the phenomenology of rotochemical heating with direct Urca reactions and uniform and isotropic superfluid energy gaps of different sizes. We first do exploratory work by integrating the thermal and chemical evolution equations numerically for different energy gaps, which uncovers a rich phenomenology of stable and unstable solutions. To understand these, we perform a stability analysis around the quasi-steady state, identifying the characteristic times of growing, decaying, and oscillating solutions. For small gaps, the phenomenology is similar to the previously studied cases, in the sense that the solutions quickly converge to a quasi-steady state. For large gaps ($\gtrsim 0.05$ MeV), these solutions become unstable, leading to a limit-cycle behavior of periodicity $\sim 10^{6-7} yr, in which the star is hot ($T_s\gtrsim 10^5$ K) for a small fraction of the cycle ($\sim 5- 20 %$), and cold for a longer time.

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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