Modeling the Anomalous Microwave Emission with Spinning Nanoparticles: No PAHs Required
Modeling the Anomalous Microwave Emission with Spinning Nanoparticles: No PAHs Required
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DOI：
10.3847/1538-4357/aa5c37
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发表时间：
2017-02-20
影响因子：
4.9
通讯作者：
Draine, B. T.
中科院分区：
文献类型：
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作者：
Hensley, Brandon S.;Draine, B. T.
鉴于最近的观测结果表明，多环芳烃的反常微波辐射(AME)和中红外辐射之间缺乏明显的相关性，我们评估了旋转硅酸盐和/或铁纳米粒子的旋转发射是否可以解释观测到的AME，而不违反对星际丰度、紫外线消光和红外辐射的观测约束。通过修改SpDust程序来计算这些颗粒的旋转发射，我们发现纳米硅酸盐颗粒可以解释观察到的AME的全部，而铁颗粒可能只占一小部分，甚至是对超小铁纳米颗粒中集中的星际铁的量的极端假设。考虑到来自多个颗粒群的贡献对总自旋尘埃排放的增加的复杂性，以及由于约束较差的颗粒大小、电荷和偶极矩分布而存在的不确定性，我们讨论了自旋尘埃理论和有助于识别AME载流子的观测试验的一般的、与载体无关的预测(S)。
In light of recent observational results indicating an apparent lack of correlation between the anomalous microwave emission (AME) and mid-infrared emission from polycyclic aromatic hydrocarbons, we assess whether rotational emission from spinning silicate and/or iron nanoparticles could account for the observed AME without violating observational constraints on interstellar abundances, ultraviolet extinction, and infrared emission. By modifying the SpDust code to compute the rotational emission from these grains, we find that nanosilicate grains could account for the entirety of the observed AME, whereas iron grains could be responsible for only a fraction, even for extreme assumptions on the amount of interstellar iron concentrated in ultrasmall iron nanoparticles. Given the added complexity of contributions from multiple grain populations to the total spinning dust emission, as well as existing uncertainties due to the poorly constrained grain size, charge, and dipole moment distributions, we discuss generic, carrier-independent predictions of spinning dust theory and observational tests that could help identify the AME carrier(s).