论文标题
中子星周围的两个温度辐射热积聚
Two-temperature radiative hot accretion flow around neutron stars
论文作者
论文摘要
进行了辐射两温热积聚流（HAF）的数值模拟周围中子恒星（NSS）。我们假设HAF围绕NS携带的所有能量都将被热化并在NS表面辐射。热光子将径向向外传播并冷却HAF Vis Comptonization。我们将$ \ dot m $定义为中心对象表面的质量积聚率（$ \ dot m _ {\ rm edd} = 10l _ {\ rm edd}/c^2 $，$ l _ {\ rm edd} $和$ c $ cum uminty and ed lumdton and和eddington均为$ l _ {\ rm edd} $。当$ \ dot m $低于$ \ sim 10^{ - 4} $时，HAF的冷却并不重要，流出非常强。当$ \ dot m> \ sim 10^{ - 3} $时，冷却变得很重要，流出明显较弱。在$ 10^{ - 4} <\ dot m <10^{ - 3} $的范围内，HAFS瞬变从强大的流出阶段到非常弱的流出阶段，增加了$ \ dot m $。还将NS周围HAF的特性与BH围绕HAF的特性进行了比较。我们发现，使用类似的$ \ dot m $，ns周围的HAF的动态属性与BH周围HAF的动力学属性非常相似。但是，由于存在来自NS表面的热软X射线组件，因此NS周围HAF的发射光谱与BH周围的HAF频谱可能完全不同。
Numerical simulations of radiative two-temperature hot accretion flows (HAFs) around Neutron stars (NSs) are performed. We assume that all of the energy carried by the HAF around a NS will be thermalized and radiated out at the surface of the NS. The thermal photons will propagate outwards radially and cool the HAF vis Comptonization. We define $\dot m$ as the mass accretion rate at the surface of the central object in unit of Eddington accretion rate ($\dot M_{\rm Edd}=10L_{\rm Edd}/c^2$, with $L_{\rm Edd}$ and $c$ being Eddington luminosity and speed of light, respectively). When $\dot m$ is lower than $\sim 10^{-4}$, the cooling of the HAF is not important and outflows are very strong. When $\dot m > \sim 10^{-3}$, cooling becomes important and outflows are significantly weak. In the range $10^{-4} < \dot m < 10^{-3}$, the HAFs transients from a strong outflow phase to a very weak outflow phase with increase of $\dot m$. The properties of the HAF around a NS are also compared to those of the HAF around a BH. We find that with a similar $\dot m$, the dynamical properties of the HAF around a NS are quite similar as those of the HAF around a BH. However, the emitted spectrum of a HAF around a NS can be quite different from that of a HAF around a BH due to the presence of a thermal soft X-ray component coming from the surface of the NS.
