The effect of low-velocity, low-mass intruders (collisionless gas) on the dynamical evolution of a binary system

Abstract

The present, 20,000 or more computer-simulated encounters between comparatively low mass intruders and binary systems pertain to the important limit where the intruder velocity is small by comparison to the orbital velocity of the binary. The dependence of the encounters on orbital eccentricity, binary component mass ratios, and the impact parameter, are found, and it is noted that while the average incraese in the binding energy is proportional to the square of the binary orbital eccentricity at zero impact parameter, the increase in the binding energy decreases much faster with increasing impact parameter as the eccentricity increases. As a result, the total cross section for increasing the binary's binding energy through encounters with low mass intruders is independent of the orbital eccentricity of the binary.