arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1702.03086astro-ph.EP
收藏

地球轨道周围尘埃分布的尺度依赖性

Size Dependence of Dust Distribution around the Earth Orbit

Takahiro Ueda, Hiroshi Kobayashi, Taku Takeuchi, Daisuke Ishihara, Toru Kondo, Hidehiro Kaneda

摘要:

在太阳系中,主要由小行星碰撞和彗星活动产生的行星际尘埃粒子由于坡印廷-罗伯逊阻力而漂移到地球轨道。我们分析了日本第一颗红外天文卫星AKARI观测到的IDPs的热辐射。观测到的地球轨道尾向表面亮度在$9{\rm μm}$波段比前向高3.7%,在$18{\rm μm}$波段比前向高3.0%。为了揭示尘埃属性导致的领先的拖尾表面亮度不对称,我们数值积分的太阳,地球和尘埃粒子的轨道作为一个限制性的三体问题,包括来自太阳的辐射。粒子的初始轨道是根据主带小行星或木星族彗星的轨道确定的。平均运动共振中的轨道捕获导致了显著的首尾不对称性,因此中等大小的尘埃(~10 - 100 ${\rm μm}$)产生了比黄道光更大的不对称性。在$9{\rm μm}$和$18{\rm μm}$波段,小行星尘埃的大小分布上积分的前后表面亮度差分别为27.7%和25.3%。相反,如果尘埃的最大半径被设置为$s_{\rm max} = 3000{\rm μm}$,则彗星尘埃的亮度差在$9{\rm μm}$和$18{\rm μm}$波段分别为3.6%和3.1%。考虑到这些值和它们的误差,我们得出结论,小行星尘埃的贡献的黄道光的红外辐射小于~10%,而彗星尘埃的数量级为1毫米主要占黄道光的红外。

英文摘要:

In the Solar System, interplanetary dust particles (IDPs) originating mainly from asteroid collisions and cometary activities drift to the Earth orbit due to the Poynting-Robertson drag. We analyzed the thermal emission from IDPs that was observed by the first Japanese infrared astronomical satellite, AKARI. The observed surface brightness in the trailing direction of the Earth orbit is 3.7% greater than that in the leading direction in the $9{\rm μm}$ band and 3.0% in the $18{\rm μm}$ band. In order to reveal dust properties causing the leading-trailing surface brightness asymmetry, we numerically integrated orbits of the Sun, the Earth, and a dust particle as a restricted three-body problem including radiation from the Sun. The initial orbits of particles are determined according to the orbits of main-belt asteroids or Jupiter-family comets. The orbital trapping in mean motion resonances results in a significant leading-trailing asymmetry so that intermediate sized dust (~10-100${\rm μm}$) produces a greater asymmetry than the zodiacal light has. The leading-trailing surface brightness difference integrated over the size distribution of the asteroidal dust is obtained to be the values of 27.7% and 25.3% in the $9{\rm μm}$ and $18{\rm μm}$ bands, respectively. In contrast, the brightness difference for cometary dust is calculated as the values of 3.6% and 3.1% in the $9{\rm μm}$ and $18{\rm μm}$ bands, respectively, if the maximum dust radius is set to be $s_{\rm max} = 3000{\rm μm}$. Taking into account these values and their errors, we conclude that the contribution of asteroidal dust to the zodiacal infrared emission is less than ~10%, while cometary dust of the order of 1 mm mainly accounts for the zodiacal light in infrared.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑