Potential Jupiter-Family Comet Contamination of the Main Asteroid Belt
Henry H. Hsieh, Nader Haghighipour
(Submitted on 28 Apr 2016)
We present the results of “snapshot” numerical integrations of test particles representing comet-like and asteroid-like objects in the inner solar system aimed at investigating the short-term dynamical evolution of objects close to the dynamical boundary between asteroids and comets as defined by the Tisserand parameter with respect to Jupiter, T_J (i.e., T_J=3). As expected, we find that T_J for individual test particles is not always a reliable indicator of initial orbit types. Furthermore, we find that a few percent of test particles with comet-like starting elements (i.e., similar to Jupiter-family comets) reach main-belt-like orbits (at least temporarily) during our 2 Myr integrations, even without the inclusion of non-gravitational forces, apparently via a combination of gravitational interactions with the terrestrial planets and temporary trapping by mean-motion resonances with Jupiter. We estimate that the fraction of real Jupiter-family comets occasionally reaching main-belt-like orbits on Myr timescales could be on the order of ~0.1-1%, although the fraction that remain on such orbits for appreciable lengths of time is certainly far lower. Thus, the number of JFC-like interlopers in the main-belt population at any given time is likely to be small, but still non-zero, a finding with significant implications for efforts to use main-belt comets to trace the primordial distribution of volatile material in the inner solar system. The test particles with comet-like starting orbital elements that transition onto main-belt-like orbits in our integrations appear to be largely prevented from reaching low eccentricity, low inclination orbits. We therefore find that low-eccentricity, low-inclination main-belt comets may provide a more reliable means for tracing the primordial ice content of the main asteroid belt than the main-belt comet population as a whole.
Comments: 31 pages, 16 figures; accepted for publication in Icarus
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1604.08557 [astro-ph.EP] (or arXiv:1604.08557v1 [astro-ph.EP] for this version)
Submission history
From: Henry Hsieh
[v1] Thu, 28 Apr 2016 18:53:53 GMT (12780kb,D)
http://arxiv.org/abs/1604.08557
