arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1111.3451astro-ph.HE
收藏

旋转驱动毫秒脉冲星不同演化阶段的X射线和Gamma-ray辐射

X-ray and Gamma-ray Emissions from Different Evolutionary Stage of Rotation Powered Millisecond Pulsars

J. Takata, K. S. Cheng, R. E. Taam

摘要:

$Fermi$ -LAT已经揭示了旋转动力毫秒双星(MSP)是银河系$γ$射线源群的主要贡献者。这样的双星在模拟几个低质量X射线双星(LMXB)的静止状态时也可能是重要的,其中伴星的光学观测表明可能存在旋转动力的MSP。为了了解不同演化阶段的MSPs的观测特性,我们研究了与外隙模型相关的X射线和$γ$射线辐射。对于旋转供电的MSP,外间隙的大小和高能发射的性质由表面附近的光子-光子对产生过程或磁对产生过程控制。对于这些类星体,我们发现由磁对产生过程控制的外隙模型在解释$γ$射线光度或非热X射线光度与自旋下降功率之间的可能相关性方面是更好的。对于静态LMXB中的吸积MSP,由深部地壳加热引起的中子星表面的热X射线发射可以控制外隙的条件。我们认为,在几个LMXB的静态观察到的光调制起源于照射的施主星的$γ$ -射线从外部间隙。在这些系统中,对于大质量的中子星,可以实现对SAXJ1808.4 -3658等源进行光学调制所需的辐照光度。最后,我们讨论了与黑寡妇系统,如PSR B1957+20的双星内激波相关的高能辐射。

英文摘要:

The $Fermi$-LAT has revealed that rotation powered millisecond pulsars (MSPs) are a major contributor to the Galactic $γ$-ray source population. Such pulsars may also be important in modeling the quiescent state of several low mass X-ray binaries (LMXBs), where optical observations of the companion star suggest the possible existence of rotation powered MSPs. To understand the observational properties of the different evolutionary stages of MSPs, the X-ray and $γ$-ray emission associated with the outer gap model is investigated. For rotation powered MSPs, the size of the outer gap and the properties of the high-energy emission are controlled by either the photon-photon pair-creation process or magnetic pair-creation process near the surface. For these pulsars, we find that the outer gap model controlled by the magnetic pair-creation process is preferable in explaining the possible correlations between the $γ$-ray luminosity or non-thermal X-ray luminosity versus the spin down power. For the accreting MSPs in quiescent LMXBs, the thermal X-ray emission at the neutron star surface resulting from deep crustal heating can control the conditions in the outer gap. We argue that the optical modulation observed in the quiescent state of several LMXBs originates from the irradiation of the donor star by $γ$-rays from the outer gap. In these systems, the irradiation luminosity required for the optical modulation of the source such as SAX J1808.4-3658 can be achieved for a neutron star of high mass. Finally, we discuss the high-energy emission associated with an intra-binary shock in black widow systems, e.g. PSR B1957+20.

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。

↑