3D radiative transfer: Continuum and line scattering in non-spherical winds from OB stars
3D radiative transfer: Continuum and line scattering in non-spherical winds from OB stars
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3D 辐射传输：OB 星非球形风中的连续散射和线散射
DOI：
10.1051/0004-6361/201731858
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发表时间：
2018
影响因子：
6.5
通讯作者：
Sundqvist J. O.
中科院分区：
文献类型：
--
作者：
Hennicker L;Puls J;Kee N. D;Sundqvist J. O.
背景最先进的定量光谱学利用合成光谱从观测中提取信息。对于热，大质量的恒星，这些合成光谱计算的一维，球对称，NLTE大气和光谱合成代码。然而，某些恒星的大气，显示出强烈的偏离球对称性，并需要在3D.AimsWe目前和测试一个新开发的三维辐射传输代码，量身定制的快速膨胀的恒星大气中的辐射场的解决方案。我们应用我们的代码的连续传输风烧蚀模型，并在磁winds.MethodsWe的紫外线共振线形成使用了3D有限体积法的时间无关的辐射传输方程的解决方案，研究连续和线散射问题，目前近似由一个两级原子。通过将形式求解器耦合到非局部近似Λ-迭代格式来加速收敛。特别强调了仔细的测试，通过比较与替代解决方案的一维，球对称模型大气。这些测试使我们能够了解某些缺点的方法，并估计极限情况下，实际上可以calculated.ResultsThe收敛的源函数的典型误差，相比，一维的解决方案，是10- 20%的顺序，并迅速增加光学厚（τ <$10）连续，主要是由于我们的解决方案的准确性的顺序。在拱星盘中，从风到盘的（光学薄）过渡区的辐射温度与风中的相应值非常相似。对于动态磁层的MHD模拟，线轮廓，计算与我们的新的3D代码，同意与以前的解决方案，使用3D-SEI方法。当与配置文件相比，从所谓的分析动力磁层（ADM）模型，然而，显着的差异变得apparent.ConclusionsDue相似的辐射温度在风和过渡区的光盘，相同的线强度分布可以应用在辐射流体动力学计算光学厚拱盘在“吸积大质量恒星”。为了正确地描述动态磁层中紫外线的形成，ADM模型需要进一步发展，至少在很大一部分的外风。
ContextState of the art quantitative spectroscopy utilizes synthetic spectra to extract information from observations. For hot, massive stars, these synthetic spectra are calculated by means of 1D, spherically symmetric, NLTE atmosphere and spectrum-synthesis codes. Certain stellar atmospheres, however, show strong deviations from spherical symmetry, and need to be treated in 3D.AimsWe present and test a newly developed 3D radiative transfer code, tailored to the solution of the radiation field in rapidly expanding stellar atmospheres. We apply our code to the continuum transfer in wind-ablation models, and to the UV resonance line formation in magnetic winds.MethodsWe have used a 3D finite-volume method for the solution of the time-independent equation of radiative transfer, to study continuum- and line-scattering problems, currently approximated by a two-level-atom. Convergence has been accelerated by coupling the formal solver to a non-local approximateΛ-iteration scheme. Particular emphasis has been put on careful tests, by comparing with alternative solutions for 1D, spherically symmetric model atmospheres. These tests allowed us to understand certain shortcomings of the methods, and to estimate limiting cases that can actually be calculated.ResultsThe typical errors of the converged source functions, when compared to 1D solutions, are of the order of 10–20%, and rapidly increase for optically thick (τ≳ 10) continua, mostly due to the order of accuracy of our solution scheme. In circumstellar discs, the radiation temperatures in the (optically thin) transition region from wind to disc are quite similar to corresponding values in the wind. For MHD simulations of dynamical magnetospheres, the line profiles, calculated with our new 3D code, agree well with previous solutions using a 3D-SEI method. When compared with profiles resulting from the so-called analytic dynamical magnetosphere (ADM) model, however, significant differences become apparent.ConclusionsDue to similar radiation temperatures in the wind and the transition region to the disc, the same line-strength distribution can be applied within radiation hydrodynamic calculations for optically thick circumstellar discs in “accreting high-mass stars”. To properly describe the UV line formation in dynamical magnetospheres, the ADM model needs to be further developed, at least in a large part of the outer wind.
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磁性 OB 星星周发射的刚性旋转磁层模型
DOI：
--
发表时间：
2004
期刊：
影响因子：
--
作者：
R. Townsend;S. Owocki
通讯作者：
S. Owocki
DOI：
--
发表时间：
1995
期刊：
影响因子：
--
作者：
K. Gayley
通讯作者：
K. Gayley
DOI：
10.1086/305350
发表时间：
1998-03
期刊：
The Astrophysical Journal
影响因子：
--
作者：
D. Hillier;Doug L. Miller
通讯作者：
D. Hillier;Doug L. Miller
DOI：
--
发表时间：
1973
期刊：
影响因子：
--
作者：
C. Cannon
通讯作者：
C. Cannon
首次对大质量恒星磁层进行 3DMHD 模拟，并将其应用于 θ1 Ori C 的 Hα 发射
影响因子：
4.8
作者：
A. ud;J. Sundqvist;S. Owocki;V. Petit;R. Townsend
通讯作者：
R. Townsend