The Formation of Free-Floating Brown Dwarves & Planetary-Mass Objects by Photo-Erosion of Prestellar Cores

Abstract

We explore the possibility that, in the vicinity of an OB star, a prestellar core which would otherwise have formed an intermediate or low-mass star may instead form a free-floating brown dwarf or planetary-mass object, because the outer layers of the core are eroded by the ionizing radiation from the OB star before they can accrete onto the protostar at the centre of the core. We find that the mechanism is robust, in the sense that it operates under a wide range of conditions, but it is also inefficient, in the sense that a rather massive core is required to produce a single brown dwarf.