The long-term evolution of neutron star merger remnants - II. Radioactively powered transients
The long-term evolution of neutron star merger remnants - II. Radioactively powered transients
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DOI：
10.1093/mnras/stt2503
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发表时间：
2014-03-01
影响因子：
4.8
通讯作者：
Piran, Tsvi
中科院分区：
文献类型：
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作者：
Grossman, Doron;Korobkin, Oleg;Piran, Tsvi
我们使用中子星合并抛射物长期演化的三维流体动力学模拟来预测由新产生的r过程核衰变提供动力的电磁瞬变的光曲线。对于潮汐和水动力相互作用下的动态抛射物，我们采用最近研究建议的10 cm(2) g（-1）的灰色不透明。对于1.3-1.4 m圆点合并的参考案例，我们发现合并后2-4天有一个宽的IR峰。峰值亮度约为2 × 10(40) erg s（-1）的平均方向，但增加了多达4个因素，更有利的二进制参数和视角。这些信号相当微弱，在引力波触发的大误差框（类似于100度(2)）内很难检测到。第二种电磁瞬变是由中微子驱动的风产生的。这些风产生的“弱”r-过程物质的强度为50 < A < 130，丰度模式在不同的合并情况下差异很大。对于采用的不透明度为1 cm(2) g(-1)，合并后约6小时的紫外/光学瞬态峰值，光度约为10(41)erg(-1)（对于0.01 m的风圆点）。这些信号在深度后续搜索（例如使用斯巴鲁上的Hypersuprime相机）中是边缘检测到的。随后对较弱但持续时间较长的红外信号的探测将有助于确定合并事件。我们简要地讨论了我们的结果对最近探测到的伴随GRB 130603B的近红外（nIR）瞬态信号的影响。
We use 3D hydrodynamic simulations of the long-term evolution of neutron star merger ejecta to predict the light curves of electromagnetic transients that are powered by the decay of freshly produced r-process nuclei. For the dynamic ejecta that are launched by tidal and hydrodynamic interaction, we adopt grey opacities of 10 cm(2) g(-1), as suggested by recent studies. For our reference case of a 1.3-1.4 M-circle dot merger, we find a broad IR peak 2-4 d after the merger. The peak luminosity is approximate to 2 x 10(40) erg s(-1) for an average orientation, but increased by up to a factor of 4 for more favourable binary parameters and viewing angles. These signals are rather weak and hardly detectable within the large error box (similar to 100 deg(2)) of a gravitational wave trigger. A second electromagnetic transient results from neutrino-driven winds. These winds produce 'weak' r-process material with 50 < A < 130 and abundance patterns that vary substantially between different merger cases. For an adopted opacity of 1 cm(2) g(-1), the resulting transients peak in the UV/optical about 6 h after the merger with a luminosity of approximate to 10(41) erg s(-1) (for a wind of 0.01 M-circle dot) These signals are marginally detectable in deep follow-up searches (e. g. using Hypersuprime camera on Subaru). A subsequent detection of the weaker but longer lasting IR signal would allow an identification of the merger event. We briefly discuss the implications of our results to the recent detection of a near infrared (nIR) transient accompanying GRB 130603B.