Other
Scientific paper
Aug 2004
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004phdt.........5c&link_type=abstract
Thesis (PhD). CORNELL UNIVERSITY, Source DAI-B 65/02, p. 787, Aug 2004, 192 pages.
Other
Scientific paper
This thesis is divided in two parts. First, we consider the dynamical mobility for members of asteroid families, while the second part concerns irregular satellites of jovian planets. Asteroid families are groupings of minor planets identified by clustering in their proper orbital elements, these objects have spectral signatures consistent with an origin in the break-up of a common parent body. From the current values of proper semimajor axes a of family members one can estimate the ejection velocities with which the fragments left the break-up event. However the ejection velocities so inferred are consistently higher than N-body and hydro-code simulations, as well as laboratory experiments, suggest. To explain this discrepancy, we study whether asteroid family members might have been ejected from the collision at low speeds and then gradually drifted to their current positions, via two mechanisms: (i)close encounters with massive asteroids, and (ii)the Yarkovsky non-gravitational effect. Because the Yarkovsky effect for km-sized bodies decreases with asteroid diameter D, it is unlikely to have appreciably moved large asteroids (say those with D > 15km) over the typical family age (1 2 Gyr). Our results show that, for ≃10% of the simulated bodies, close encounters increased the “inferred” ejection velocities from sub-100 m/s up to values of 150 m/s, beyond what hydro-code and N-body simulations suggest are the maximum possible initial ejection velocity for members of the Adeona and Gefion families with D > 15 km. Thus this mechanism of mobility may be responsible for the unusually high “inferred” ejection speeds of a few of the largest family members. The second part of the thesis concerns the dynamics of irregular satellites of jovian planets, moons that occupy large orbits of significant eccentricity e and/or inclination I, and circle each of the giant planets. The irregulars often extend close to the orbital stability limit, about 1/3 1/2 of the size of their planet's Hill sphere. The distant, elongated and inclined orbits suggest capture, which pre-sumably would give a random distribution of inclinations. Yet, none of the 100+ known irregulars have inclinations (relative to the ecliptic) between 55° and 141°. We show that many high-I orbits are unstable due to secular solar perturbations. High- inclination orbits suffer appreciable periodic changes in eccentricity; large eccentricities can either drive particles with 70° < I < 110° deep into the realm of the regular satellites (where collisions and scatterings may remove them from planetocentric orbits) or expel them from the planet's Hill sphere. Finally, we study chaotic orbits in the region of the Kozai resonance near the orbit of Kiviuq, a saturnian irregular satellite. Our results show that the Kozai resonance is crossed by a web of secondary resonances, whose arguments involve combinations of the argument of pericenter, the Great-Inequality's argument (2λJupiter - 5λ Saturn), longitude of the node Ω, and other terms related to the planetary secular frequencies g5, g6, and s6. Circulating test, particles whose precession period are close to the Great- Inequality period (883 yrs), or some of its harmonics; are caught in these secondary resonances, and show significant chaotic behavior.
No associations
LandOfFree
Dynamics of asteroid families and irregular satellites of jovian planets does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Dynamics of asteroid families and irregular satellites of jovian planets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dynamics of asteroid families and irregular satellites of jovian planets will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1098000