Kilonova from post-merger ejecta as an optical and near-infrared counterpart of GW170817
Kilonova from post-merger ejecta as an optical and near-infrared counterpart of GW170817
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DOI：
10.1093/pasj/psx121
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发表时间：
2017-10
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通讯作者：
Masaomi Tanaka;Y. Utsumi;P. Mazzali;N. Tominaga;Michitoshi Yoshida;Y. Sekiguchi;T. Morokuma;K. Motohara;K. Ohta;K. Kawabata;F. Abe;K. Aoki;Y. Asakura;S. Baar;S. Barway;I. Bond;M. Doi;T. Fujiyoshi;H. Furusawa;S. Honda;Y. Itoh;M. Kawabata;N. Kawai;J. H. Kim;Chien-Hsiu Lee;S. Miyazaki;K. Morihana;H. Nagashima;T. Nagayama;T. Nakaoka;F. Nakata;R. Ohsawa;T. Ohshima;H. Okita;Tomoki Saito;T. Sumi;A. Tajitsu;J. Takahashi;M. Takayama;Y. Tamura;I. Tanaka;T. Terai;P. Tristram;N. Yasuda;T. Zenko
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文献类型：
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作者：
Masaomi Tanaka;Y. Utsumi;P. Mazzali;N. Tominaga;Michitoshi Yoshida;Y. Sekiguchi;T. Morokuma;K. Motohara;K. Ohta;K. Kawabata;F. Abe;K. Aoki;Y. Asakura;S. Baar;S. Barway;I. Bond;M. Doi;T. Fujiyoshi;H. Furusawa;S. Honda;Y. Itoh;M. Kawabata;N. Kawai;J. H. Kim;Chien-Hsiu Lee;S. Miyazaki;K. Morihana;H. Nagashima;T. Nagayama;T. Nakaoka;F. Nakata;R. Ohsawa;T. Ohshima;H. Okita;Tomoki Saito;T. Sumi;A. Tajitsu;J. Takahashi;M. Takayama;Y. Tamura;I. Tanaka;T. Terai;P. Tristram;N. Yasuda;T. Zenko
最近从中子星星（NS）合并事件GW 170817的引力波的检测和电磁对应物的识别提供了一个独特的机会，研究在NS合并的物理过程。为了获得从NS合并喷出的材料的属性，我们进行kilonova，光学和近红外辐射的辐射传输模拟供电的r-过程核的放射性衰变的合并中合成。我们发现，观测到的近红外发射持续超过10天的解释是0.03 Msun的喷出物含有镧系元素。然而，在初始阶段观察到的蓝色光学成分需要具有相对高的电子分数（Ye）的喷出物成分。我们表明，光学和近红外发射同时再现的喷出物与介质叶~ 0.25。我们认为，一个占主导地位的组件供电的排放合并后的喷出物，这表明，质量喷射后，第一次动态喷射是相当有效的。我们的研究结果表明，NS合并综合了广泛的r-过程元素，并加强了假设，NS合并是宇宙中的r-过程元素的起源。
Recent detection of gravitational waves from a neutron star (NS) merger event GW170817 and identification of an electromagnetic counterpart provide a unique opportunity to study the physical processes in NS mergers. To derive properties of ejected material from the NS merger, we perform radiative transfer simulations of kilonova, optical and near-infrared emissions powered by radioactive decays of r-process nuclei synthesized in the merger. We find that the observed near-infrared emission lasting for > 10 days is explained by 0.03 Msun of ejecta containing lanthanide elements. However, the blue optical component observed at the initial phases requires an ejecta component with a relatively high electron fraction (Ye). We show that both optical and near-infrared emissions are simultaneously reproduced by the ejecta with a medium Ye of ~ 0.25. We suggest that a dominant component powering the emission is post-merger ejecta, which exhibits that mass ejection after the first dynamical ejection is quite efficient. Our results indicate that NS mergers synthesize a wide range of r-process elements and strengthen the hypothesis that NS mergers are the origin of r-process elements in the Universe.