Explosive ejections generated by gravitational interactions

Abstract

During the fragmentation and collapse of a molecular cloud, it is expected to have close encounters between (proto)stellar objects that can lead to the ejection of a fraction of them as runaway objects. However, the duration and the consequences of such encounters perhaps are small such that there is no direct evidence of their occurrence. As a first approximation, in this work, we analytically analyze the interaction of a massive object that moves at high velocity into a cluster of negligible mass particles with an initial number density distribution $\propto R^{-\alpha }$. We have found that the runaway conditions of the distribution after the encounter are related to the mass and the velocity of the star and the impact parameter of each particle to the stellar object. Then, the cluster particles are gravitationally accelerated by the external approaching star, destroying the cluster and the dispersion and velocities of the particles have explosive characteristics. We compare this analytical model with several numerical simulations and finally, we applied our results to the Orion Fingers in the Orion BN/KL region, which show an explosive outflow that could be triggered by the gravitational interaction of several (proto)stellar objects.

12 pages

References in corpus (9)

• Theory of Star Formation
• Dynamics of Planetary Systems in Star Clusters
• The ALMA View of the OMC1 Explosion in Orion
• The Orion Protostellar Explosion and Runaway Stars Revisited: Stellar Masses, Disk Retention, and an Outflow from BN
• The Proper Motions of the Double Radio Source n in the Orion BN/KL Region
• Winds from clu\sters with non-uniform stellar distributions
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• G5.89: An Explosive Outflow Powered by a Proto-Stellar Merger?
• Formation of Orion Fingers