arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2003.04955astro-ph.EPphysics.ao-ph
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海王星外天体的挥发演化和大气

Volatile evolution and atmospheres of Trans-Neptunian Objects

Leslie A. Young, Felipe Braga-Ribas, Robert E. Johnson

摘要:

在30-50 K(柯伊伯带表面的典型温度)下(例如Stern & Trafton 2008),只有七种物质的升华压力高于1毫巴(Fray & Schmitt 2009):Ne、N $_2$、CO、Ar、O $_2$、CH $_4$和Kr。其中,N $_2$、CO和CH $_4$已经在海王星外天体(TNO)的表面上被探测到或推断出。这些挥发性冰上方的稀薄大气取决于升华压力,升华压力对挥发性冰的成分、温度和混合状态非常敏感。因此,挥发分在TNO上的滞留与其形成环境和热历史有关。表面挥发物可能是通过季节性变化的大气输送的,它们的凝结可能是其中一些天体表面高辐射的原因。对稀薄大气最敏感的搜索是通过恒星掩星的方法进行的,这对海卫一和冥王星的大气研究至关重要,迄今为止已经对其他11个天体的大气设定了上限。最近发布的盖亚天体测量目录导致了一个“黄金时代”的能力,预测TNO掩星,以增加观测数据库。

英文摘要:

At 30-50 K, the temperatures typical for surfaces in the Kuiper Belt (e.g. Stern & Trafton 2008), only seven species have sublimation pressures higher than 1 nbar (Fray & Schmitt 2009): Ne, N$_2$, CO, Ar, O$_2$, CH$_4$, and Kr. Of these, N$_2$, CO, and CH$_4$ have been detected or inferred on the surfaces of Trans-Neptunian Objects (TNOs). The presence of tenuous atmospheres above these volatile ices depends on the sublimation pressures, which are very sensitive to the composition, temperatures, and mixing states of the volatile ices. Therefore, the retention of volatiles on a TNO is related to its formation environment and thermal history. The surface volatiles may be transported via seasonally varying atmospheres and their condensation might be responsible for the high surface albedos of some of these bodies. The most sensitive searches for tenuous atmospheres are made by the method of stellar occultation, which have been vital for the study of the atmospheres of Triton and Pluto, and has to-date placed upper limits on the atmospheres of 11 other bodies. The recent release of the Gaia astrometric catalog has led to a "golden age" in the ability to predict TNO occultations in order to increase the observational data base.

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。

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