Meteor observations as a tool to constrain cosmogonic models of the Solar System

TL;DR

The paper tackles constraining cosmogonic Solar System models by inferring the Oort cloud's ice-to-rock ratio from meteor observations. It analyzes two AMOS databases to identify large rocky meteoroids on cometary orbits with $T_J<2$ and to classify material using $K_B$, $P_E$, and $P_{E,\mathrm{mod}}$, with a mass threshold of $m_\infty \ge 1$ g. Fluxes are derived using a geometric model of the AMOS effective area, applying $F(m>m_{\mathrm{lim}}) = \frac{N(m>m_{\mathrm{lim}})}{A_{\mathrm{eff}} t_{obs}}$, and estimating $A_{\mathrm{eff}}$ and $t_{obs}$ through two approaches. Initial results identify 9 rocky meteoroids on Oort-cloud-like orbits and 53 cometary meteoroids, demonstrating the viability of meteor-based constraints on cosmogonic models. The study lays groundwork for comparing observed meteor fluxes with model predictions to infer the Oort cloud's composition and to discriminate among competing cosmogonic scenarios.

Abstract

Recent observations of small bodies of the Solar System showed evidence of the presence of refractory (asteroidal) material in the Oort cloud. Different models of the origin of the Solar System predict different numbers of rocky objects in the Oort cloud, meaning that measurement of this population can be used as an observational constraint for cosmogonic models. The aim of our work is to study how the data obtained from meteor observations can be used as a tool for distinguishing among the existing cosmogonic models. We investigated two meteor databases collected by the cameras of the All-Sky Meteor Orbit System (AMOS) located in the Canary Islands and in Chile. We describe methodology and results of the search for unusually strong rocky meteoroids on cometary orbits with the origin in the Oort cloud. These data will be used to calculate the fluxes of meteors of different compositions in order to constrain the ratio of icy and rocky components of the Oort cloud. For the flux determination, we estimate the observational time and effective area of the AMOS system.

Figures (3)

• Figure 1: Geometry of AMOS Canary (left) and AMOS Chile (right) stations used in this work.
• Figure 2: Representation of the effective area for a double-station meteor observation (schematic side view). Outer, light blue area represents the atmosphere, inner yellow area represents the Earth, dashed black line is the sea level. $H$ is the height above sea level for which the effective area is calculated, $R_1, R_2$ are the Earth's radii at station locations, $h_1, h_2$ are altitudes of each station, angles $\alpha_1, \alpha_2$ represent angular fields of view of each camera. Green (towards the left) and dark blue (towards the right) areas are the areas seen by individual stations. Red area in middle, where green and dark blue overlap, is the effective area $A_\mathrm{eff}$ observed by both cameras.
• Figure 3: Representation of the effective area of the Canary stations (schematic top view). Green and blue dots represent individual cameras. Stations are aligned along x-axis. Green (left) and blue (right) areas are the areas seen by individual stations. For each camera, the longer side of the green/blue polygon corresponds to the longer side of the FOV. Central red intersection is the effective area.