arXiv 0905.38182009-05astro-ph.HE

对类星体热X射线发射的认识

Toward an understanding of thermal X-ray emission of pulsars

M. Yu, R. X. Xu

备注：: Astroparticle Physics Accepted

摘要：

我们提出了一个理论模型的热X射线发射和冷却的孤立双星，假设双星是固体夸克星。我们计算了这类夸克星的热容，结果表明剩余热能不能维持典型孤立X射线星的热X射线亮度.我们的结论是，其他加热机制必须在运作中，如果实际上是固体夸克星的恒星。两种可能的加热机制进行了探讨。首先，对于磁层活动很少的超新星，来自星际介质或相关超新星遗迹中的物质的吸积可能为观测到的热辐射提供动力。在螺旋桨区，盘吸积率${\dot M}\sim$为爱丁顿吸积率的1%，并以$\sim 0.1% {\dot M}$的吸积率吸积到恒星表面，可以解释孤立的昏暗中子星和中心致密天体观测到的发射光度。其次，对于磁层活动显著的脉冲星，其自旋下降光度可能是通过反向等离子体电流流动产生热能的来源。脉冲星辐射热X射线光度与自旋能量损失率之间的唯象研究表明，可能存在1/2定律或线性定律，即$L_{\rm bol}^{\infty}\propto\dot{E}^{1/2}$或$L_{\rm bol}^{\infty}\propto\dot{E}$。这一结果与固体夸克星的热性质一起使我们能够计算此类恒星的热演化。计算了热演化曲线或冷却曲线，并与从17个活跃的X射线天体获得的"温度-年龄"数据进行了比较。结果表明，这些辐射源的辐射热X射线观测与固体夸克星脉冲星模型是一致的。

英文摘要：

We present a theoretical model for the thermal X-ray emission and cooling of isolated pulsars, assuming that pulsars are solid quark stars. We calculate the heat capacity for such a quark star, and the results show that the residual thermal energy cannot sustain the observed thermal X-ray luminosities seen in typical isolated X-ray pulsars. We conclude that other heating mechanisms must be in operation if the pulsars are in fact solid quark stars. Two possible heating mechanisms are explored. Firstly, for pulsars with little magnetospheric activities, accretion from the interstellar medium or from the material in the associated supernova remnants may power the observed thermal emission. In the propeller regime, a disk-accretion rate ${\dot M}\sim$1% of the Eddington rate with an accretion onto the stellar surface at a rate of $\sim 0.1% {\dot M}$ could explain the observed emission luminosities of the dim isolated neutron stars and the central compact objects. Secondly, for pulsars with significant magnetospheric activities, the pulsar spindown luminosities may have been as the sources of the thermal energy via reversing plasma current flows. A phenomenological study between pulsar bolometric X-ray luminosities and the spin energy loss rates presents the probable existence of a 1/2-law or a linear law, i.e. $L_{\rm bol}^{\infty}\propto\dot{E}^{1/2}$ or $L_{\rm bol}^{\infty}\propto\dot{E}$. This result together with the thermal properties of solid quark stars allow us to calculate the thermal evolution of such stars. Thermal evolution curves, or cooling curves, are calculated and compared with the `temperature-age' data obtained from 17 active X-ray pulsars. It is shown that the bolometric X-ray observations of these sources are consistent with the solid quark star pulsar model.

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。

摘要：

英文摘要：

相关论文