论文标题

赞美:模拟无线电来源中解决的光谱演变

PRAiSE: Resolved spectral evolution in simulated radio sources

论文作者

Yates-Jones, Patrick M., Turner, Ross J., Shabala, Stanislav S., Krause, Martin G. H.

论文摘要

我们提出了一种将空间分辨的绝热和辐射损失过程应用于来自活性银河核(AGN)无线电的流体动力模拟的合成无线电发射的方法。 Lagrangian示踪剂颗粒,每个颗粒代表电子集合,都注入模拟和自记录以来的位置,网格压力以及时间。这些数量用于通过无线电源跟踪电子数据包的损失,类似于半分析环境(升高)形式主义的无线电AGN,后者使用全局源属性来计算每个粒子外词的发射率。通过这种方法的后处理性质提供了选择观察参数(包括红移)的自由。我们将此框架应用于在不同环境(包括不对称环境)中的喷气机的仿真。我们发现无线电源特性对频率和红移的强烈依赖性与观察结果和先前的建模工作非常吻合。由于高红移时更突出的反群体损失,无线电光谱的强劲演变具有红移。较密集的环境中的无线电源具有平坦的光谱指数,这表明光谱指数不对称可能是有用的环境示踪剂。我们模拟了中间的马赫数喷射,该机器数喷射在到达叶的尖端之前中断,并发现它们保留了边缘闪烁的Fanaroff-Riley II型形态,我们研究的所有环境和我们研究的所有环境和红移,最突出的发射量保持在裂片尖端附近。

We present a method for applying spatially resolved adiabatic and radiative loss processes to synthetic radio emission from hydrodynamic simulations of radio sources from active galactic nuclei (AGN). Lagrangian tracer particles, each representing an ensemble of electrons, are injected into simulations and the position, grid pressure, and time since the last strong shock are recorded. These quantities are used to track the losses of the electron packet through the radio source in a manner similar to the Radio AGN in Semi-analytic Environments (RAiSE) formalism, which uses global source properties to calculate the emissivity of each particle ex-situ. Freedom in the choice of observing parameters, including redshift, is provided through the post-processing nature of this approach. We apply this framework to simulations of jets in different environments, including asymmetric ones. We find a strong dependence of radio source properties on frequency and redshift, in good agreement with observations and previous modelling work. There is a strong evolution of radio spectra with redshift due to the more prominent inverse-Compton losses at high redshift. Radio sources in denser environments have flatter spectral indices, suggesting that spectral index asymmetry may be a useful environment tracer. We simulate intermediate Mach number jets that disrupt before reaching the tip of the lobe, and find that these retain an edge-brightened Fanaroff-Riley Type II morphology, with the most prominent emission remaining near the tip of the lobes for all environments and redshifts we study.

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