Applications of an improved Monte Carlo code to the synthesis of early-time Supernova spectra
Applications of an improved Monte Carlo code to the synthesis of early-time Supernova spectra
复制标题
改进的蒙特卡罗代码在早期超新星光谱合成中的应用
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
P. Mazzali
中科院分区：
文献类型：
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作者：
P. Mazzali
一个最初为恒星风开发的蒙特卡罗程序，后来被修改为计算超新星光球相的合成光谱，该程序采用了物质框架中相干散射形成谱线的简化假设。在一个改进的代码（露西1999a），线吸收的一包辐射能量是由相同数量的能量在物质框架中的发射之前，但现在的包的光子的频率选择，以便，统计，分支到可用的允许向下跃迁是正确的表示。这种分支的包含对于超新星光谱是有一定重要性的，正如平托和伊士曼（2000）在光变曲线研究中所强调的那样。新规范还采用了改进的谱线表，并采用形式积分计算了新规范的涌现谱。合成光谱计算与这种新的代码Ia型和II型超新星的例子，并介绍了引入分支的改进进行了讨论。以前的结果与一个纯散射的代码被证明是不会失效。可能进一步的代码开发，以实现一个完整的NLTE蒙特卡罗代码进行了简要介绍。
A Monte Carlo code developed originally for stellar winds and subsequently modified to compute synthetic spectra for the photospheric phases of supernovae adopted the simplifying assumption of line formation by coherent scattering in the matter frame. In an improved code (Lucy 1999a), the line absorption of a packet of radiant energy is followed as before by the emission of an identical amount of energy in the matter frame but now the frequency of the packet’s photons is chosen so that, statistically, the branching into the available permitted downward transitions is correctly represented. This inclusion of branching is of some importance for supernova spectra, as emphasized in the light curve studies of Pinto & Eastman (2000). An improved line list is also adopted in the new code, and the emergent spectrum is computed using the formal integral. Examples of synthetic spectra computed with this new code for supernovae of types Ia and II are presented and the improvements introduced by the incorporation of branching are discussed. Previous results obtained with a pure scattering code are shown not to be invalidated. Possible further code developments to achieve a fully NLTE Monte Carlo code are briefly described.