Binary Survival in the Outer Solar System. (arXiv:1905.02282v1 [astro-ph.EP])
<a href="http://arxiv.org/find/astro-ph/1/au:+Nesvorny_D/0/1/0/all/0/1">David Nesvorny</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vokrouhlicky_D/0/1/0/all/0/1">David Vokrouhlicky</a>
As indicated by their special characteristics, the cold classical Kuiper belt
objects (KBOs) formed and survived at 42-47 au. Notably, they show a large
fraction of equal-size binaries whose formation is probably related to the
accretion of KBOs themselves. These binaries are uncommon in other –hot,
resonant, scattered– populations, which are thought to have been implanted
from the massive disk below 30 au to >30 au during Neptune’s migration. Here we
highlight the possibility that equal-size binaries formed in the disk but were
subsequently removed by impacts and/or dynamical effects (e.g., scattering
encounters with Neptune). We determine the dependence of these processes on the
size and separation of binary components. Our results indicate that tighter
binaries, if they formed in the massive disk, have relatively good chances of
survival (unless the disk was long-lived). In contrast, the widest binaries in
the hot population, such as 2002 VF130, have a very low survival probability
(<1%) even if the massive disk was short-lived. They may represent a trace of
lucky survivors of a much larger population of the original disk binaries, or
they formed at ~30-40~au and dodged the impact- and encounter-related
perturbations that we studied here. We find that all known satellites of the
largest KBOs would survive during the dynamical implantation of these bodies in
the Kuiper belt. The low orbital eccentricities of Pluto's small moons may have
been excited by impacts and/or encounters of the Pluto system to Neptune.
As indicated by their special characteristics, the cold classical Kuiper belt
objects (KBOs) formed and survived at 42-47 au. Notably, they show a large
fraction of equal-size binaries whose formation is probably related to the
accretion of KBOs themselves. These binaries are uncommon in other –hot,
resonant, scattered– populations, which are thought to have been implanted
from the massive disk below 30 au to >30 au during Neptune’s migration. Here we
highlight the possibility that equal-size binaries formed in the disk but were
subsequently removed by impacts and/or dynamical effects (e.g., scattering
encounters with Neptune). We determine the dependence of these processes on the
size and separation of binary components. Our results indicate that tighter
binaries, if they formed in the massive disk, have relatively good chances of
survival (unless the disk was long-lived). In contrast, the widest binaries in
the hot population, such as 2002 VF130, have a very low survival probability
(<1%) even if the massive disk was short-lived. They may represent a trace of
lucky survivors of a much larger population of the original disk binaries, or
they formed at ~30-40~au and dodged the impact- and encounter-related
perturbations that we studied here. We find that all known satellites of the
largest KBOs would survive during the dynamical implantation of these bodies in
the Kuiper belt. The low orbital eccentricities of Pluto’s small moons may have
been excited by impacts and/or encounters of the Pluto system to Neptune.
http://arxiv.org/icons/sfx.gif
