论文标题
各向同性球形密度簇（II）物理特性和碰撞前核心的负热容量
Self-similar orbit-averaged Fokker-Planck equation for isotropic spherical dense clusters (ii) physical properties and negative heat capacity of pre-collapse core
论文作者
论文摘要
这是我们有关自相似轨道平均福克群岛（OAFP）方程的一系列作品的第二篇论文，并详细介绍了各向同性前崩溃解决方案的物理特性。球形恒星簇的后期后期的基本核心崩溃过程可以用自相似的OAFP方程来描述。最近在第一篇论文中发现了准确的光谱溶液。目前的工作详细介绍了基于从溶液中获得的恒星DF的模型的热力学方面。我们的计算显示了以下本地属性（i）状态方程为$ p =1.0ρ/χ_\ text {esc {esc} $，其中$ p $是压力，$ρ$的密度和$χ_\ text {ens cevt {ens cistect {Esc} $缩放的逃生能量，而它是$ p = 0.5ρ^{1.1} {1.1} {1.1}/up text $ atect $ prade。 （ii）如果我们认为核心的中心是多环形的，则多环形指数为177。此外，作为全球性质，我们构建了模型的热量曲线，以便与病毒一起讨论热容量。特别的重点是核心负热容量的原因。可以直接将良好的放射线芯与阳性热容量的等温球进行比较。将我们的结果与以前的作品进行比较，我们得出结论，在自相似的演化中，由于无碰撞和高温恒星的负热容量会产生，这些恒星经历了通过恒星和热流的平均场电位迅速变化，而不是由于核心与周围环境的（准）隔离。
This is the second paper of a series of our works on the self-similar orbit-averaged Fokker-Planck (OAFP) equation and details physical properties of isotropic pre-collapse solution. The fundamental core collapse process at the late stage of relaxation evolution of spherical star clusters can be described by the self-similar OAFP equation. The accurate spectral solution was found recently in the first paper. The present work details the thermodynamic aspects of the model based on the stellar DF obtained from the solution. Our calculation shows the following local properties (i) Equation of state is $p=1.0ρ/χ_\text{esc}$ in the core where $p$ is the pressure, $ρ$ the density and $χ_\text{esc}$ the scaled escape energy, while it is $p=0.5ρ^{1.1}/χ_\text{esc}$ at large radii. (ii) If we consider the center of the core is polytropic, the polytropic index is 177. Also, as a global property we construct caloric curves of the model to discuss the heat capacity together with Virial. Special focus is the cause of negative heat capacity of the core; the well-relaxed core can be directly compared to the isothermal sphere with positive heat capacity. Comparing our results to the previous works, we conclude, in the self-similar evolution, the negative heat capacity in the core holds due to collisionless and high-temperature stars that experience a rapid change in mean field potential through stellar- and heat- flows, rather than due to the (quasi-)isolation of the core from surroundings.
