Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Orbital Modification of the Himalia Family during an Early Solar System Dynamical Instability

Li, Daohai LU orcid and Christou, Apostolos A. (2017) In The Astronomical Journal 154(5).
Abstract

Among the irregular satellites orbiting Jupiter, the Himalia family is characterized by a high velocity dispersion dv of several hundred m s-1 among its members, inconsistent with a collisional origin. Efforts to account for this through internecine gravitational interactions do not readily reproduce this feature. Here, we revisit the problem in the context of recent cosmogonical models, where the giant planets migrated significantly through interaction with a planetesimal disk and suffered encounters with planetesimals and planet-sized objects. Our starting assumption is that family formation either predated this phase or occurred soon after its onset. We simulate numerically the diffusive effect of three distinct... (More)

Among the irregular satellites orbiting Jupiter, the Himalia family is characterized by a high velocity dispersion dv of several hundred m s-1 among its members, inconsistent with a collisional origin. Efforts to account for this through internecine gravitational interactions do not readily reproduce this feature. Here, we revisit the problem in the context of recent cosmogonical models, where the giant planets migrated significantly through interaction with a planetesimal disk and suffered encounters with planetesimals and planet-sized objects. Our starting assumption is that family formation either predated this phase or occurred soon after its onset. We simulate numerically the diffusive effect of three distinct populations of perturbers on a set of test particles representing the family: Moonsized (MPT) and Pluto-sized (PPT) planetesimals, and planetary-mass objects (PMO) with masses typical of icegiant planets. We find that PPT flybys are inefficient, but encounters with MPTs raise the dv of ∼60% of our test particles to >200 m s-1 with respect to Himalia, in agreement with observations. As MPTs may not have been abundant in the disk, we simulate encounters between Jupiter and PMOs. We find that too few encounters generate less dispersion than MPTs while too many essentially destroy the family. For PMO masses in the range 520 mA, the family orbital distribution is reproduced by a few tens of encounters.

(Less)
Please use this url to cite or link to this publication:
author
and
publishing date
type
Contribution to journal
publication status
published
subject
keywords
celestial mechanics, planets and satellites: dynamical evolution and stability, planets and satellites: individual (Himalia family)
in
The Astronomical Journal
volume
154
issue
5
article number
209
publisher
IOP Publishing
external identifiers
  • scopus:85034454479
ISSN
0004-6256
DOI
10.3847/1538-3881/aa8fc9
language
English
LU publication?
no
id
c0716f28-a7c3-4142-89a3-212b104092f0
date added to LUP
2019-04-29 13:32:45
date last changed
2022-04-25 23:01:49
@article{c0716f28-a7c3-4142-89a3-212b104092f0,
  abstract     = {{<p>Among the irregular satellites orbiting Jupiter, the Himalia family is characterized by a high velocity dispersion dv of several hundred m s<sup>-1</sup> among its members, inconsistent with a collisional origin. Efforts to account for this through internecine gravitational interactions do not readily reproduce this feature. Here, we revisit the problem in the context of recent cosmogonical models, where the giant planets migrated significantly through interaction with a planetesimal disk and suffered encounters with planetesimals and planet-sized objects. Our starting assumption is that family formation either predated this phase or occurred soon after its onset. We simulate numerically the diffusive effect of three distinct populations of perturbers on a set of test particles representing the family: Moonsized (MPT) and Pluto-sized (PPT) planetesimals, and planetary-mass objects (PMO) with masses typical of icegiant planets. We find that PPT flybys are inefficient, but encounters with MPTs raise the dv of ∼60% of our test particles to &gt;200 m s-1 with respect to Himalia, in agreement with observations. As MPTs may not have been abundant in the disk, we simulate encounters between Jupiter and PMOs. We find that too few encounters generate less dispersion than MPTs while too many essentially destroy the family. For PMO masses in the range 520 m<sub>A</sub>, the family orbital distribution is reproduced by a few tens of encounters.</p>}},
  author       = {{Li, Daohai and Christou, Apostolos A.}},
  issn         = {{0004-6256}},
  keywords     = {{celestial mechanics; planets and satellites: dynamical evolution and stability; planets and satellites: individual (Himalia family)}},
  language     = {{eng}},
  month        = {{11}},
  number       = {{5}},
  publisher    = {{IOP Publishing}},
  series       = {{The Astronomical Journal}},
  title        = {{Orbital Modification of the Himalia Family during an Early Solar System Dynamical Instability}},
  url          = {{http://dx.doi.org/10.3847/1538-3881/aa8fc9}},
  doi          = {{10.3847/1538-3881/aa8fc9}},
  volume       = {{154}},
  year         = {{2017}},
}