A dynamical survey of the trans-Neptunian space II.: Diffusion and stability

Kővári Emese, Kovács Tamás, Forgács-Dajka Emese (2022.01.01 - 2022.03.30)
Eötvös Loránd University, Center for Astrophysics and Space Science

Abstract: The trans-Neptunian space is of great interest of dynamical studies with an inexhaustible number of intriguing problems to be solved. Our aim is to carry out a large-scale survey of trans-Neptunian objects (TNOs) by means of dynamical maps. In the first part of the research, we concentrate on the dynamical role of mean-motion resonances (MMRs) among the TNOs, and the tools of understanding are dynamical maps of classical chaos indicators. In the second part, our focus becomes the quantification of the chaotic diffusion and that of the stability times of the small bodies. The chaotic diffusion is of fundamental importance for its rate will determine the long-term dynamics of a given celestial system. To estimate the rate of the diffusion (that is, to compute the diffusion coefficients) in the case of the 4125 TNOs selected in the first part of our study, we initiate the use of the Shannon entropy. This latter quantity allows, on the one hand, to measure the extent of unstable regions in the phase space (and thus serves as an indicator of chaos), and also enables the direct measurement of the diffusion coefficients. The characteristic times of stability - in the case of normal diffusion - are then achieved by taking the inverse of the diffusion coefficients. In the knowledge of the chaotic diffusion and stability times for as large a TNO sample as the one indicated above, the overall structure of the trans-Neptunian space might be mapped as well, along with the specification of dynamical classes or the update of the existing ones.

Next Post Previous Post