Angular momentum of two collided rarefied preplanetesimals and formation of binaries

TL;DR

This paper investigates the angular momentum resulting from collisions of rarefied preplanetesimals and proposes models explaining binary formation, including dual contraction centers and disk formation leading to satellites.

Contribution

It introduces models linking collision angular momentum to binary formation, explaining high binary fractions at greater solar distances and potential dual contraction centers.

Findings

Models explain binary formation at larger heliocentric distances.

Binaries can have nearly equal masses and large separations.

Disks around primaries can form, leading to satellite creation.

Abstract

The mean angular momentum associated with the collision of two celestial objects moving in almost circular heliocentric orbits was studied. The results of these studies were used to develop models of the formation of binaries at the stage of rarefied preplanetesimals. The models can explain a greater fraction of binaries formed at greater distances from the Sun. Sometimes there could be two centers of contraction inside the rotating preplanetesimal formed as the result of a collision between two rarefied preplanetesimals. Such formation of binaries could result in binaries with almost the same masses of components separated by a large distance. Formation of a disk around the primary could result because the angular momentum that was obtained by a rarefied preplanetesimal formed by collision was greater than the critical angular momentum for a solid body. One or several satellites of the primary could be formed from the disk.