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标题：OSSOS. IX. Two Objects in Neptune's 9:1 Resonance—Implications for Resonance Sticking in the Scattering Population
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作者：Kathryn Volk ; Ruth A. Murray-Clay ; Brett J. Gladman 等
期刊名称：The Astronomical journal
印刷版ISSN：0004-6256
电子版ISSN：1538-3881
出版年度：2018
卷号：155
期号：6
页码：1-9
DOI：10.3847/1538-3881/aac268
语种：English
出版社：American Institute of Physics
摘要：We discuss the detection in the Outer Solar System Origins Survey (OSSOS) of two objects in Neptune’s distant 9:1 mean motion resonance at semimajor axis a≈130 au. Both objects are securely resonant on 10Myr timescales, with one securely in the 9:1 resonance’s leading asymmetric libration island and the other in either the symmetric or trailing asymmetric island. These objects are the largest semimajor axis objects with secure resonant classifications, and their detection in a carefully characterized survey allows for the first robust resonance population estimate beyond 100au. The detection of these objects implies a 9:1 resonance population of 1.1×104 objects with Hr<8.66 (D 100 km) on similar orbits (95% confidence range of ∼(0.4–3)×104). Integrations over 4Gyr of an ensemble of clones spanning these objects’ orbit-fit uncertainties reveal that they both have median resonance occupation timescales of ∼1Gyr. These timescales are consistent with the hypothesis that these objects originate in the scattering population but became transiently stuck to Neptune’s 9:1 resonance within the last ∼1Gyr of solar system evolution. Based on simulations of a model of the current scattering population, we estimate the expected resonance sticking population in the 9:1 resonance to be 1000–4500 objects with Hr<8.66; this is marginally consistent with the OSSOS 9:1 population estimate. We conclude that resonance sticking is a plausible explanation for the observed 9:1 population, but we also discuss the possibility of a primordial 9:1 population, which would have interesting implications for the Kuiper Belt’s dynamical history.
关键词：Kuiper belt: general