Sources of zodiacal dust

TL;DR

This study estimates the proportions of asteroidal, cometary, and trans-Neptunian particles in zodiacal dust using models and observations, finding roughly equal contributions from each source with specific orbital characteristics.

Contribution

The paper provides a quantitative analysis of the sources of zodiacal dust, integrating numerical models with observational data to estimate the fractions from different origins.

Findings

Approximately one-third of zodiacal dust originates from each of asteroidal, cometary, and trans-Neptunian sources.

Particles from Encke-type comets constitute no more than 15% of the dust population.

Trans-Neptunian particles are not dominant inside Jupiter's orbit due to distribution constraints.

Abstract

Fractions of asteroidal particles, particles originating beyond Jupiter's orbit (including trans-Neptunian particles), and cometary particles originating inside Jupiter's orbit among zodiacal dust are estimated to be about 1/3 each, with a possible deviation from 1/3 up to 0.1-0.2. These estimates were based on the comparison of our models of the zodiacal cloud that use results of numerical integration of the orbital evolution of dust particles produced by asteroids, comets, and trans-Neptunian objects with different observations (e.g., WHAM [Wisconsin H-Alpha Mapper spectrometer] observations of spectra of zodiacal light, the number density at different distances from the Sun). The fraction of particles produced by Encke-type comets (with e~0.8-0.9) does not exceed 0.15 of the overall population. The estimated fraction of particles produced by long-period and Halley-type comets among zodiacal dust also does not exceed 0.1-0.15. Though trans-Neptunian particles fit different observations of dust inside Jupiter's orbit, they cannot be dominant in the zodiacal cloud because studies of the distribution of number density with a distance from the Sun shows that trans-Neptunian particles cannot be dominant between orbits of Jupiter and Saturn. Mean eccentricities of zodiacal particles that better fit the WHAM observations were about 0.2-0.5, with a more probable value of about 0.3.