An improved model for the infrared emission from the zodiacal dust cloud: cometary, asteroidal and interstellar dust
An improved model for the infrared emission from the zodiacal dust cloud: cometary, asteroidal and interstellar dust
复制标题
黄道尘埃云红外发射的改进模型：彗星、小行星和星际尘埃
DOI：
--
复制
发表时间：
2012
期刊：
影响因子：
--
通讯作者：
B. May
中科院分区：
文献类型：
--
作者：
M. Rowan‐Robinson;B. May
我们模拟了IRAS和COBE探测到的黄道带尘埃的红外发射，目的是估计小行星、彗星和星际尘埃对黄道带云的相对贡献。我们最重要的结果是探测到由星际尘埃引起的前景辐射的各向同性成分。众所周知，太阳系内部的尘埃呈扇形分布。如果假设这延伸到火星轨道，我们发现彗星、小行星和星际尘埃分别占风扇尘埃的70%、22%和7.5%。如果假设扇子延伸到木星的轨道，我们会发现一个更糟糕的匹配。我们的模型与尤利西斯号和其他航天器探测到的行星际尘埃的分析大体一致。我们对太阳系内部星际尘埃的质量密度的估计与尤利西斯的估计一致，为1.5 au，但比尤利西斯的估计高出一个数量级。在我们的模型中，到达地球的黄道带尘埃中只有1%是星际尘埃。我们的模型可以通过基于地面的黄道带云的运动学研究来进一步测试，这需要延长数年的时间来监测星际尘埃中的太阳周期变化，通过动态模拟和航天器的现场测量。
We model the infrared emission from zodiacal dust detected by the IRAS and COBE missions, with the aim of estimating the relative contributions of asteroidal, cometary and interstellar dust to the zodiacal cloud. Our most important result is the detection of an isotropic component of foreground radiation due to the interstellar dust. The dust in the inner Solar system is known to have a fan-like distribution. If this is assumed to extend to the orbit of Mars, we find that cometary, asteroidal and interstellar dust account for 70, 22 and 7.5 per cent of the dust in the fan. We find a worse fit if the fan is assumed to extend to the orbit of Jupiter. Our model is broadly consistent with the analysis of interplanetary dust detected by Ulysses and other spacecraft. Our estimate of the mass–density of interstellar dust in the inner Solar system is consistent with estimates from Ulysses at 1.5 au, but is an order of magnitude higher than Ulysses estimates at r > 4 au. Only 1 per cent of the zodiacal dust arriving at the earth would be interstellar, in our model. Our models can be further tested by ground-based kinematical studies of the zodiacal cloud, which need to extend over a period of years to monitor solar cycle variations in interstellar dust, by dynamical simulations, and by in situ measurements from spacecraft.