发表机构
Tsung-Dao Lee Institute, Shanghai Jiao-Tong University; Institute of Fundamental Physics and Quantum Technology, School of Physical Science and Technology, Ningbo University; Zhejiang Key Laboratory of Extreme Universe; School of Physics & Astronomy, Shanghai Jiao-Tong University; Key Laboratory for Particle Physics, Astrophysics and Cosmology, Shanghai Key Laboratory for Particle Physics and Cosmology, Shanghai Jiao-Tong University; Institut für Theoretische Physik, Goethe Universität; Mullard Space Science Laboratory, University College London; Institut für Theoretische Physik und Astrophysik, Universität Würzburg（上海交大李政道研究所; 宁波大学物理科学与技术学院基础物理与量子技术研究所; 浙江极端宇宙重点实验室; 上海交通大学物理与天文学院; 上海交通大学粒子物理、天体物理与宇宙学重点实验室; 法兰克福歌德大学理论物理研究所; 伦敦大学学院穆拉德空间科学实验室; 维尔茨堡大学理论与天体物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文通过GRMHD模拟和GRRT计算，量化了不同状态方程和电子加热模型对黑洞吸积流热力学及合成图像的影响，发现可变EoS更自洽且变率更大，对EHT观测建模至关重要。
AI 中文摘要
已有文献记载，黑洞阴影图像主要由时空几何和控制吸积流的等离子体微观物理决定。然而，状态方程（EoS）的影响仍未得到充分探索。本文中，我们量化了不同的等离子体微观物理设定，特别是EoS和电子加热模型的选择，如何影响流热力学及相应的合成黑洞图像。我们使用两种常数-γ理想EoS（γ=4/3和5/3）以及一种依赖温度的可变EoS（TM），在两种吸积流状态——标准及正常演化（SANE）和磁 arrested 盘（MAD）——下进行了三维广义相对论磁流体动力学（GRMHD）模拟。动力学模型通过广义相对论辐射转移（GRRT）计算在86GHz和230GHz下进行后处理，采用热和混合κ电子分布函数用于同步辐射。我们还比较了基于湍流加热和磁重联的两种温度电子加热方案。常数-γ EoS在盘和喷流区域系统性地高估或低估气体和电子温度，而可变EoS提供了两种极限状态之间更平滑的跨相对论插值。这些差异实质性地影响同步辐射发射率、图像形态和通量变率幅度。特别是，可变EoS表现出比常数-γ模型系统性地更大的时间变率。这些结果表明，采用物理自洽的EoS描述对于吸积流热力学和如事件视界望远镜（EHT）观测的地平线尺度图像的逼真建模至关重要。
英文摘要
Previous literature has documented that black hole shadow images are mainly shaped by spacetime geometry and plasma microphysics governing accretion flows. However, the influence of equations of state (EoS) remains under-explored. In this paper, we quantify how different plasma microphysics prescriptions, specifically the choice of EoS and electron-heating models, affect flow thermodynamics and the corresponding synthetic black-hole images. We perform three-dimensional general-relativistic magnetohydrodynamics (GRMHD) simulations using two constant-$γ$ ideal EoSs with $γ= 4/3$ and 5/3 and a temperature-dependent variable EoS (TM) in both accretion flow states: Standard And Normal Evolution (SANE) and Magnetically Arrested Disk (MAD) regimes. The dynamical models are post-processed with general-relativistic radiative transfer (GRRT) calculations at 86GHz and 230GHz, employing thermal and hybrid $κ$ electron distribution functions for synchrotron radiation. We also compare the two-temperature electron heating prescription based on turbulent heating and magnetic reconnection. The constant-$γ$ EoSs systematically overestimate or underestimate gas and electron temperatures across disk and jet regions, whereas the variable EoS provides a smoother trans-relativistic interpolation between the two limiting regimes. These differences substantively impact the synchrotron emissivity, image morphology, and the amplitude of flux variability. In particular, the variable EoS exhibits systematically larger temporal variability than the constant-$γ$ models. These results demonstrate that adopting a physically self-consistent description of the EoS is essential for realistic modeling of accretion-flow thermodynamics and horizon-scale images like Event Horizon Telescope (EHT) observations.
Comments21 pages, 20 figures, 0 table, accepted for publication in the ApJ
