Could 1I/&#39;Oumuamua be an Icy Fractal Aggregate?

doi:10.3847/2041-8213/ab05df

	Could 1I/'Oumuamua be an Icy Fractal Aggregate?
	Moro-Martin, Amaya
	2019-02-20
发表期刊	ASTROPHYSICAL JOURNAL LETTERS
ISSN	2041-8205
EISSN	2041-8213
卷号	872 期号:2
摘要	1I/'Oumuamua is the first interstellar interloper to be detected, and it shows a non-gravitational acceleration that cannot be accounted for by outgassing, given the strict upper limits of outgassing evident from Spitzer observations, unless the relative abundances of the common volatiles are very different to those in comets. As an alternative, it has been suggested that its peculiar acceleration is due to radiation pressure, requiring a planar-sheet geometry of an unknown natural or artificial origin. Here we assess whether or not the internal structure of 1I/'Oumuamua, rather than its geometry, could support a radiation-pressure-driven scenario. We adopt a mass fractal structure and find that the type of aggregate that could yield the required area-to-mass ratio would have to be extraordinarily porous, with a density similar to 10(-5) g cm(-3). Such porous aggregates can naturally arise from the collisional grow of icy dust particles beyond the snowline of a protoplanetary disk, and we propose that 1I/'Oumuamua might be a member of this population. This is a hypothesis worth investigating because, if this were the case, 1I/'Oumuamua would have opened a new observation window on to the study of the building blocks of planets around other stars. This could set unprecedented constraints on planet formation models.
关键词	ISM: individual objects (1I/2017 U1) minor planets, asteroids: general protoplanetary disks planets and satellites: formation
DOI	10.3847/2041-8213/ab05df
收录类别	SCI
语种	英语
WOS关键词	Astronomy & Astrophysics
WOS研究方向	Science & Technology
WOS类目	Astronomy & Astrophysics
WOS记录号	WOS:000459572300002
出版者	IOP PUBLISHING LTD
引用统计
文献类型	期刊论文
专题	任务一_子任务一循证社会科学证据集成任务一
作者单位	Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA
推荐引用方式 GB/T 7714	Moro-Martin, Amaya. Could 1I/'Oumuamua be an Icy Fractal Aggregate?[J]. ASTROPHYSICAL JOURNAL LETTERS,2019,872(2).
APA	Moro-Martin, Amaya.(2019).Could 1I/'Oumuamua be an Icy Fractal Aggregate?.ASTROPHYSICAL JOURNAL LETTERS,872(2).
MLA	Moro-Martin, Amaya."Could 1I/'Oumuamua be an Icy Fractal Aggregate?".ASTROPHYSICAL JOURNAL LETTERS 872.2(2019).