AN INVESTIGATION OF THE TYPE M MORPHOLOGICAL STRUCTURE OF IC59: A NEW MODEL FOR BRIGHT RIM CLOUDS?

We report the results from a smoothed particle hydrodynamics simulation designed to model recent observational data on the nebula and Bright Rim Cloud IC59. We further examine, in the context of radiative-driven implosion (RDI) models, the possible formation mechanisms of the morphological structure of IC59. The results of the simulation reveal the existence of a new, fourth morphological state for Bright Rim Clouds (BRCs)-which we propose to call a Type M BRC morphology. We discuss the necessary conditions for the appearance of Type M BRCs, based on analytical and numerical simulations. The simulated physical properties from our model are consistent with the available observations of IC59. We further show that the prospect of RDI triggered star formation in all Type M BRCs is not supported by the simulations.