发表机构
University of Pennsylvania; National Research Council of Canada, Herzberg Astronomy and Astrophysics Research Centre; University of Victoria; Northern Arizona University; Space Telescope Science Institute; Center for Astrophysics — Harvard & Smithsonian; University of Michigan（宾夕法尼亚大学; 加拿大国家研究委员会赫茨伯格天体物理学研究中心; 维多利亚大学; 北亚利桑那大学; 太空望远镜科学研究所; 哈佛-史密森尼天体物理中心; 密歇根大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用JWST观测数据拟合冷经典海王星外天体的星等与质量分布，发现其符合对数正态分布，总质量约1.7-2.7×10⁻³地球质量，并指出流不稳定性模拟与观测存在差异。
AI 中文摘要
冷经典海王星外天体（CCs）是唯一可观测的原位星子残留群体，据信它们逃脱了碰撞磨蚀。最近的JWST观测使得拟合CCs在$5<H_r<13$范围内的微分绝对星等分布$dN/dH$成为可能，并据此推断跨越至少5个数量级质量的微分质量分布$dN/dM$。我们发现$dN/dM$可由对数正态分布很好地拟合，同样也可由广义$\Gamma$分布或双幂律分布很好地拟合。每对数质量间隔内CC总质量的最大比例位于直径约75公里或约$10^{-7.5}M_\oplus$的天体中。将拟合的$dN/dH$函数外推到$H_r>13$是不明智的，因为不同的解析形式会发散。目前仍不清楚$dN/dH$是否在暗端发生转折。CC带总质量的不确定性主要源于$M$与$H$之间关系的不确定性。利用CC双星进行的校准表明CC总质量为1.7--2.7$\times10^{-3}\\,M_\oplus$。数据中可能存在较小天体密度较低和/或反照率较高的趋势，这将降低估算的CC总质量。将推导出的质量分布与流不稳定性（SI）数值模拟结果进行定性比较表明，模拟产生的$dN/dM$分布比CCs的更尖锐，且在亮端更陡。这些差异可能归因于经典带中尚未纳入模型的非均匀形成条件。目前，由最先进的SI模拟推导出的$dN/dM$的多样性和不确定性排除了对SI假说的任何决定性检验。
英文摘要
The cold classical trans-Neptunian objects (CCs) are the only observable \textit{in situ} population of planetesimal remnants believed to have escaped collisional grinding. Recent JWST observations make it possible to fit the differential absolute magnitude distribution $dN/dH$ of the CCs from $5<H_r<13,$ and infer the differential mass distribution $dN/dM$ across $\ge5$ orders of magnitude in mass. We find $dN/dM$ well fit by a lognormal distribution, and equally well by a generalized $Γ$ distribution or a double power law. The maximum fraction of the total CC mass per log interval in $M$ is in bodies near 75~km diameter, or $\approx10^{-7.5}M_\oplus.$ Extrapolation of the fitted $dN/dH$ functions to $H_r>13$ is unwise, as the different analytic forms diverge. It remains unclear if $dN/dH$ turns over at faint $H.$ The uncertainty in the total mass of the CC belt is dominated by uncertainty in the relation between $M$ and $H$. A calibration using CC binaries suggests a total CC mass of 1.7--2.7$\times10^{-3}\,M_\oplus.$ A trend toward lower density and/or higher albedo for smaller bodies may be present in the data, and would lower the estimated total CC mass. Qualitative comparison of the derived mass distribution to the results of numerical simulations of the streaming instability (SI) suggest the simulations produce $dN/dM$ distributions that are more sharply peaked, and steeper at the bright end, than the CCs. Such differences could be ascribed to inhomogeneous formation conditions in the classical belt that are not yet included in modeling. The variety and uncertainty of $dN/dM$ derived from state-of-the-art SI simulations currently preclude any definitive test of the SI hypothesis.
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