Benchmarking the calculation of stochastic heating and emissivity of dust grains in the context of radiative transfer simulations
Benchmarking the calculation of stochastic heating and emissivity of dust grains in the context of radiative transfer simulations
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DOI：
10.1051/0004-6361/201525998
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发表时间：
2015-08-01
影响因子：
6.5
通讯作者：
Steinacker, Juergen
中科院分区：
文献类型：
--
作者：
Camps, Peter;Misselt, Karl;Steinacker, Juergen
上下文随机加热尘埃颗粒的热辐射在尘埃介质的辐射传输问题中起着重要的作用。因此，在研究空间分布和其他模式参数对模拟观测值的影响之前，验证RT代码正确地计算了沙尘排放是必要的。我们定义了一个适当的问题，基准灰尘发射率计算的RT模拟的背景下，特别是包括从SHGs的排放。我们的目的是提供一个自包含的指南，这样的功能的实施者，并提供洞察到的各种近似和实施的参与代码，以加速计算的效果。基准问题的定义包括一个典型的天文尘埃混合物与硅酸盐，石墨和PAH组件的光学和量热材料的性能和粒度分布。它还包括一系列分析定义的辐射场，尘埃种群将暴露于其中，以及所需输出的说明。我们处理这个问题，使用六个RT代码参与这个基准的努力，并将结果与参考解决方案计算与公开可用的粉尘排放代码DustEM.Results.参与的代码实现不同的算法以将计算时间保持在可接受的水平。我们研究了这些机制的影响计算的解决方案和报告的水平（不）参与代码之间的协议。对于所有的，但最极端的输入领域，我们发现在10%的协议在整个重要的波长范围3 μ m
Context. Thermal emission by stochastically heated dust grains (SHGs) plays an important role in the radiative transfer (RT) problem for a dusty medium. It is therefore essential to verify that RT codes properly calculate the dust emission before studying the effects of spatial distribution and other model parameters on the simulated observables.Aims. We define an appropriate problem for benchmarking dust emissivity calculations in the context of RT simulations, specifically including the emission from SHGs. Our aim is to provide a self-contained guide for implementors of such functionality and to offer insight into the effects of the various approximations and heuristics implemented by the participating codes to accelerate the calculations.Methods. The benchmark problem definition includes the optical and calorimetric material properties and the grain size distributions for a typical astronomical dust mixture with silicate, graphite, and PAH components. It also includes a series of analytically defined radiation fields to which the dust population is to be exposed and instructions for the desired output. We processed this problem using six RT codes participating in this benchmark effort and compared the results to a reference solution computed with the publicly available dust emission code DustEM.Results. The participating codes implement different heuristics to keep the calculation time at an acceptable level. We study the effects of these mechanisms on the calculated solutions and report on the level of (dis) agreement between the participating codes. For all but the most extreme input fields, we find agreement within 10% across the important wavelength range 3 mu m