More Realistic Planetesimal Masses Alter Kuiper Belt Formation Models and Add Stochasticity
Icarus(2024)
摘要
We perform simulations here that include the gravitational effects of the
primordial planetesimal belt consisting of 10^5 massive bodies. In our
simulations, Neptune unlocks from resonance with the other giant planets and
begins to migrate outward due to interactions with planetesimals before a
planetary orbital instability is triggered, and afterward, residual Neptunian
migration completes the formation of the modern Kuiper belt. Our present work
exhibits a number of notable differences from prior work. First, Neptune's
planetary resonance unlocking requires the Neptunian 3:2 mean motion resonance
to sweep much of the primordial disk interior to 30 au prior to the giant
planet instability. The pre-instability population of planetesimals is
consequently lower in semimajor axis, eccentricity, and inclination, and this
effect persists after the instability. Second, direct scattering between
Pluto-mass bodies and other small bodies removes material from Neptunian
resonances more efficiently than resonant dropout resulting from small changes
in Neptune's semimajor axis during scattering between Pluto-mass bodies and
Neptune. Thus, the primordial population of Pluto-mass bodies may be as few as
200 objects. Finally, our simulation end states display a wide variety of
orbital distributions, and clear relationships between final bulk Kuiper belt
properties and Neptune's migration or initial planetesimal properties largely
elude us. In particular, we find that the rapid, stochastic planetary orbital
evolution occurring during the giant planet instability can significantly alter
final Kuiper belt properties such as its inclination dispersion and the
prominence of resonant populations. This complicates using modern Kuiper belt
properties to confidently constrain early solar system events and conditions,
including planetary orbital migration and the primordial Kuiper belt's
characteristics.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要