arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1910.04448astro-ph.HE
收藏

用毫秒级双星的X射线观测加强r模振幅的界限

Strengthening the bounds on the r-mode amplitude with X-ray observations of millisecond pulsars

Tuğba Boztepe, Ersin Göğüs, Tolga Güver, Kai Schwenzer

摘要:

r模式振荡已被证明具有限制快速自旋中子星的组成的巨大潜力。由于它们的高旋转速率,如果可以推断出它们的表面温度,毫秒级恒星(MSP)提供了一个独特的平台来限制这种振荡的性质。我们提出了我们的档案X射线数据的一些MSP,以及最近的XMM牛顿观测PSR J1810+1744和PSR J2241-5236的调查结果。使用中子星大气(NSA)模型,并考虑到各种不确定性,我们提出了这些源的表面温度的新的界限。因此,我们显着加强以前的界限的r-模式振荡的振幅在毫秒脉冲,并找到严格的值低至$α\lesssim 3 \times 10^{-9}$。这比中子星的标准饱和机制所能提供的要低三个数量级,而标准饱和机制需要内部有非常强的耗散,这强烈地表明这些源的结构复杂或成分奇特。在这样低的温度下,源甚至可能在不稳定区域之外,考虑到各种不确定性,我们获得了一个简单的频率范围,低于该频率范围,在旋转较慢的恒星中排除了r模式。

英文摘要:

r-mode oscillations have been shown to have a significant potential to constrain the composition of fast spinning neutron stars. Due to their high rotation rates, millisecond pulsars (MSPs) provide a unique platform to constrain the properties of such oscillations, if their surface temperatures can be inferred. We present the results of our investigations of archival X-ray data of a number of MSPs, as well as recent XMM-Newton observations of PSR J1810+1744 and PSR J2241-5236. Using the neutron star atmosphere (NSA) model and taking into account various uncertainties, we present new bounds on the surface temperature of these sources. Thereby we significantly strengthen previous bounds on the amplitude of the r-mode oscillations in millisecond pulsars and find rigorous values as low as $α\lesssim 3 \times 10^{-9}$. This is by now about three orders of magnitude below what standard saturation mechanisms in neutron stars could provide, which requires very strong dissipation in the interior, strongly pointing towards a structurally complex or exotic composition of these sources. At such low temperatures sources could even be outside of the instability region, and taking into account the various uncertainties we obtain for an observed surface temperature a simple frequency bound below which r-modes are excluded in slower spinning pulsars.

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。

↑