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arXiv 1902.01904astro-ph.HEastro-ph.SR
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Ia型超新星的光谱序列。II。碳作为爆炸机理的诊断工具

Spectral sequences of Type Ia supernovae. II. Carbon as a diagnostic tool for explosion mechanisms

E. Heringer, M. H. van Kerkwijk, S. A. Sim, W. E. Kerzendorf, Melissa L. Graham

摘要:

一颗惰性的碳氧白矮星如何爆炸成Ia型超新星仍然是未知的。理论模型的一个有希望的测试是限制未燃烧材料的分布,特别是碳。到目前为止,大多数调查使用线识别代码来检测喷出物中的碳,这种方法无法与模型预测进行比较,因为它需要假设不透明度和温度。在这里,我们使用层析成像技术来研究SN~ 2011 fe内层中的碳含量,从Mazzali等人先前发表的层析成像分析开始。从早期光学中碳特征的存在及其后来的消失,我们推导出$13500 \lesssim v \lesssim 16000\ \rm{km\ s^{-1}}$范围内速度的平均碳质量分数在0.001和0.05之间,并且在该区域内的上限为0.005。基于我们的模型和假设的密度分布,只有少量的碳应该处于中性状态,太少了,不能对以前被确定为中性碳的近红外光谱中看到的特征负责;我们讨论了这种差异的可能原因。我们将我们的结果与一套爆炸模型进行比较,尽管模型和模拟中的不确定性使得很难得出明确的结论。

英文摘要:

How an otherwise inert carbon-oxygen white dwarf can be made to explode as a Type Ia supernova remains unknown. A promising test of theoretical models is to constrain the distribution of material that is left unburned, in particular of carbon. So far, most investigations used line identification codes to detect carbon in the ejecta, a method that cannot be readily compared against model predictions because it requires assumed opacities and temperatures. Here, we instead use tomographic techniques to investigate the amount of carbon in the inner layers of SN~2011fe, starting from the previously published tomographic analysis of Mazzali et al. From the presence of the carbon feature in the optical at early epochs and its disappearance later on, we derive an average carbon mass fraction between 0.001 and 0.05 for velocities in the range $13500 \lesssim v \lesssim 16000\ \rm{km\ s^{-1}}$, and an upper limit of 0.005 inside that region. Based on our models and the assumed density profile, only small amounts of carbon should be in the neutral state, too little to be responsible for features seen in near-infrared spectra that were previously identified as due to neutral carbon; We discuss possible reasons for this discrepancy. We compare our results against a suite of explosion models, although uncertainties in both the models and our simulations make it difficult to draw definitive conclusions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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