Dust yields in clumpy supernova shells: SN 1987A revisited
Dust yields in clumpy supernova shells: SN 1987A revisited
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DOI：
10.1111/j.1365-2966.2006.11336.x
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发表时间：
2006-11
影响因子：
4.8
通讯作者：
B. Ercolano;M. Barlow;B. Sugerman
中科院分区：
文献类型：
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作者：
B. Ercolano;M. Barlow;B. Sugerman
我们提出了一个研究的成团的影响上的出射光谱能量分布（SED）从尘埃超新星（SN）壳照明的漫辐射源分布在整个介质。这些模型适用于年龄超过几百天的II型超新星，此时能量输入主要是来自56 Co衰变的γ射线。完全三维辐射输运问题的解决，使用Monte Carlo代码，MOCASSIN，我们提出了一套模型，旨在调查的SED的灵敏度，各种聚簇参数。我们发现，与分析处方的预测相反，光学和红外（IR）观测数据集的组合足以约束尘埃质量，即使在光学厚团块存在的情况下。使用平滑变化和聚集的颗粒密度分布，我们通过拟合Wooden等人在两个时期（第615天和第775天）的光学和红外分光光度数据，获得了II型SN 1987 A凝聚的尘埃质量的新估计。当使用无定形碳颗粒时，我们对观测数据的最佳拟合意味着，到第615天，SN 1987 A的包层中约有2.0 x 10 - 4 M O的尘埃凝结，到第775天，在2.0 x 10 - 4和4.2 x 10 - 3 M O之间。我们发现，在观测到的中红外光谱中没有硅酸盐发射或吸收特征意味着SN 1987 A周围形成的尘埃中不超过15%可能是硅酸盐颗粒的形式。我们的模型对石墨颗粒的情况需要更大的尘埃质量，即在第615天在4.2 x 10 - 4和6.6 x 10 - 4 M之间，在第775天在4.5 x 10 - 4和7.5 x 10 - 4 M之间。从我们的数值模型中，我们得出的尘埃质量SN 1987 A是以前的分析成团石墨颗粒质量估计相媲美，至少两个数量级低于0.1-0.3 M的已被预测为尘埃颗粒在原始的核心塌陷SN喷出物凝聚。SN 1987 A的这种低冷凝效率与SN 2003 gd的情况相反，后者的尘埃冷凝效率最近估计高达0.12。
We present a study of the effects of clumping on the emergent spectral energy distribution (SED) from dusty supernova (SN) shells illuminated by a diffuse radiation source distributed throughout the medium. These models are appropriate for Type II SNe older than a few hundred days, when the energy input is dominated by γ-rays from 56 Co decay. The fully 3D radiation transport problem is solved using a Monte Carlo code, MOCASSIN, and we present a set of models aimed at investigating the sensitivity of the SEDs to various ·clumping parameters. We find that, contrary to the predictions of analytical prescriptions, the combination of an optical and infrared (IR) observational data set is sufficient to constrain dust masses even in the case where optically thick clumps are present. Using both smoothly varying and clumped grain density distributions, we obtain new estimates for the mass of dust condensed by the Type II SN 1987A by fitting the optical and IR spectrophotometric data of Wooden et al. at two epochs (day 615 and day 775). When using amorphous carbon grains, our best fits to the observational data imply that about 2.0 x 10 -4 M O of dust had condensed in the envelope of SN 1987A by day 615 and between 2.0 x 10 -4 and 4.2 x 10 -3 M ⊙ by day 775. We find that the absence of a silicate emission or absorption feature in the observed mid-IR spectra implies that no more than 15 per cent of the dust formed around SN 1987A can have been in the form of silicate particles. Our models require larger dust masses for the case of graphite grains, namely between 4.2 x 10 -4 and 6.6 x 10 -4 M ⊙ at day 615 and between 4.5 x 10 -4 and 7.5 x 10 -4 M ⊙ at day 775. From our numerical models, we derive dust masses for SN 1987A that are comparable to previous analytic clumped graphite grain mass estimates, and at least two orders of magnitude below the 0.1-0.3 M ⊙ that have been predicted to condense as dust grains in primordial core-collapse SN ejecta. This low condensation efficiency for SN 1987A is in contrast to the case of SN 2003gd, for which a dust condensation efficiency as large as 0.12 has recently been estimated.