The Combined Ultraviolet, Optical, and Near-infrared Light Curves of the Kilonova Associated with the Binary Neutron Star Merger GW170817: Unified Data Set, Analytic Models, and Physical Implications
The Combined Ultraviolet, Optical, and Near-infrared Light Curves of the Kilonova Associated with the Binary Neutron Star Merger GW170817: Unified Data Set, Analytic Models, and Physical Implications
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DOI：
10.3847/2041-8213/aa9c84
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发表时间：
2017-10
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通讯作者：
V. Villar;J. Guillochon;E. Berger;B. Metzger;P. Cowperthwaite;M. Nicholl;K. Alexander;P. Blanchard-P.-Blanchar
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作者：
V. Villar;J. Guillochon;E. Berger;B. Metzger;P. Cowperthwaite;M. Nicholl;K. Alexander;P. Blanchard-P.-Blanchar
我们首次对双中子星合并GW170817的电磁对应体的紫外、光学和近红外数据集进行了汇总、均匀化和统一建模。通过收集来自18篇不同论文和46种不同仪器的所有可用数据，我们能够识别和减轻单个数据集之间的系统偏移，并识别出明确的外围测量值，由此修剪和调整的数据集为扩展千nova的研究提供了机会。统一的数据集包括647个单独的通量测量值，跨越合并后0.45-29.4天，因此比任何单一数据集对物理模型具有更大的约束能力。我们测试了一些半解析模型，发现数据可以用三组分千诺瓦模型很好地建模：具有和的“蓝色”贫镧组分（cm2 g−1）和具有和的中间不透明度“紫色”组分（cm2 g−1）和具有和的“红色”富镧组分（cm2 g−1）。我们进一步探讨了喷射不对称的可能性及其对估计参数的影响。从推断的参数中，我们得出了有关各种喷射成分的物理机制，中子星的特性，并结合最新的合并率，通过该通道进行r过程富集的含义的结论。为了便于今后对这一关键事件的研究，我们公开了统一的数据集和建模代码。
We present the first effort to aggregate, homogenize, and uniformly model the combined ultraviolet, optical, and near-infrared data set for the electromagnetic counterpart of the binary neutron star merger GW170817. By assembling all of the available data from 18 different papers and 46 different instruments, we are able to identify and mitigate systematic offsets between individual data sets and to identify clear outlying measurements, with the resulting pruned and adjusted data set offering an opportunity to expand the study of the kilonova. The unified data set includes 647 individual flux measurements, spanning 0.45–29.4 days post-merger, and thus has greater constraining power for physical models than any single data set. We test a number of semi-analytical models and find that the data are well modeled with a three-component kilonova model: a “blue” lanthanide-poor component ( cm2 g−1) with and an intermediate opacity “purple” component ( cm2 g−1) with and and a “red” lanthanide-rich component ( cm2 g−1) with and . We further explore the possibility of ejecta asymmetry and its impact on the estimated parameters. From the inferred parameters we draw conclusions about the physical mechanisms responsible for the various ejecta components, the properties of the neutron stars, and, combined with an up-to-date merger rate, the implications for r-process enrichment via this channel. To facilitate future studies of this keystone event we make the unified data set and our modeling code public.