Constraining Inputs to Realistic Kilonova Simulations through Comparison to Observed r-process Abundances
Constraining Inputs to Realistic Kilonova Simulations through Comparison to Observed r-process Abundances
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DOI：
10.3847/1538-4357/acf3e0
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发表时间：
2022-06
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影响因子：
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通讯作者：
M. Ristić;E. Holmbeck;R. Wollaeger;O. Korobkin;E. Champion;R. O’Shaughnessy;Chris L. Fryer;C. Fontes;M. Mumpower;T. Sprouse
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作者：
M. Ristić;E. Holmbeck;R. Wollaeger;O. Korobkin;E. Champion;R. O’Shaughnessy;Chris L. Fryer;C. Fontes;M. Mumpower;T. Sprouse
Kilonovae是与中子星星合并有关的电磁辐射源之一，由富含中子的合并喷出物中的放射性同位素衰变提供动力。与GW 170817的电磁对应物一致的kilonova排放模型预测了特征丰度模式，该模式由流出物中不同类型物质的相对平衡决定。假设观测到的源是典型的，这个推断的丰度模式反过来必须与通过其他方法推断的r-过程丰度相匹配，例如在太阳系中观测到的。我们报告的分析比较我们的辐射传输模拟中采用的输入质量加权的元素组成的元素在太阳中的质量分数，作为一个实际的原型，潜在的普遍丰度签名中子星星合并。我们的参数推断结果取决于我们假设的成分的动力和风喷出物，并检查如何与以前的工作相比，新的结果。我们发现，使用FRDM 2012核质量和FRLDM裂变模型计算的动态喷出物成分具有极丰富的中子喷出物（Y e = 0.035）沿着，（Y e = 0.27）风喷出物成分产生风与动力质量比M w /M d = 0.47，这与观测到的AT 2017 gfo kilonova光变曲线最匹配，同时也产生了太阳系中最匹配的中子捕获元素丰度，尽管考虑到系统学，该比率可能高达1阶。
Kilonovae, one source of electromagnetic emission associated with neutron star mergers, are powered by the decay of radioactive isotopes in the neutron-rich merger ejecta. Models for kilonova emission consistent with the electromagnetic counterpart to GW170817 predict characteristic abundance patterns, determined by the relative balance of different types of material in the outflow. Assuming that the observed source is prototypical, this inferred abundance pattern in turn must match r-process abundances deduced by other means, such as what is observed in the solar system. We report on analysis comparing the input mass-weighted elemental compositions adopted in our radiative transfer simulations to the mass fractions of elements in the Sun, as a practical prototype for the potentially universal abundance signature from neutron star mergers. We characterize the extent to which our parameter inference results depend on our assumed composition for the dynamical and wind ejecta and examine how the new results compare to previous work. We find that a dynamical ejecta composition calculated using the FRDM2012 nuclear mass and FRLDM fission models with extremely neutron-rich ejecta (Y e = 0.035) along with moderately neutron-rich (Y e = 0.27) wind ejecta composition yields a wind-to-dynamical mass ratio of M w /M d = 0.47, which best matches the observed AT2017gfo kilonova light curves while also producing the best-matching abundance of neutron capture elements in the solar system, though, allowing for systematics, the ratio may be as high as of order unity.