标题： 小到中型冥王星外天体的表面：倾角与表面类型之间关联的证据 显示英文标题

标题： The Surfaces of Small to Mid-Size Plutinos: Evidence of an Association Between Inclination and Surface Type

摘要： 作为与海王星最人口众多的平均运动共振（MMR）之一，并且靠近当今冷经典盘的内部边界，对3:2 MMR中冥王星族的轨道和表面类别分布的观测提供了关于海王星迁移的约束，并深入了解了迁移前星子盘的组成结构。 在这里，我们通过grz波长范围观测了43个中小型（H_V >~5）柯伊伯带天体（TNOs）的表面反照率，其中14个是冥王星族。 我们使用Fraser及其合作者提出的双表面类别模型（FaintIR和BrightIR表面类别）对这些TNOs的表面进行分类，其中FaintIR表面类别主要由冷经典天体组成。 将文献中类似冥王星族的观测结果纳入总样本量为43个冥王星族的情况下，我们发现FaintIR和BrightIR冥王星族的瞬时倾角分布（i_osc）在99.3%的显著性水平上具有统计学差异，其中（6/7）个i_osc > 4.5{\deg }的冥王星族具有FaintIR表面。 这最容易用以下解释：在被俘获到3:2共振之前，FaintIR和BrightIR星子在原始星子盘中沿径向进行了分区。 虽然这可能是过去具有FaintIR表面的原始冷经典盘在太阳方向上更宽约3天文单位的证据，但我们不能排除另一种解释，即这些FaintIR冥王星族是从~42.5-48 au区域被散射出来并被捕获到3:2共振中的。 显示英文摘要

摘要： Being one of the most populated mean motion resonances (MMR) with Neptune and lying close to the inner boundary of the present day cold classical disk, observations of the orbital and surface class distributions of the plutinos in the 3:2 MMR provide constraints on Neptune's migration and insight into the compositional structure of the pre-migration planetesimal disk. Here, we present observations of the surface reflectance of 43 small to mid-size (H_V >~ 5) transneptunian objects (TNOs) through the grz wavelength range, 14 of which are plutinos. We classify the surfaces of these TNOs using the two-surface class model (FaintIR and BrightIR surface classes) proposed by Fraser and collaborators, where the FaintIR surface class is dominated by cold classicals. Incorporating similar observations of plutinos from the literature for a total sample size of 43 plutinos, we find that the osculating inclination distributions (i_osc) of the FaintIR and BrightIR plutinos are statistically distinguishable at 99.3% significance, where (6/7) of the plutinos with i_osc > 4.5{\deg} have FaintIR surfaces. This is most easily explained if the FaintIR and BrightIR planetesimals were radially partitioned in the primordial planetesimal disk before being captured into the 3:2 resonance. While this could be evidence that the primordial cold classical disk with FaintIR surfaces was broader in the past by ~3 au in the sunward direction, we cannot rule out the alternative explanation that these FaintIR plutinos were scattered from the ~42.5-48 au region from the Sun and captured into the 3:2 resonance.