From cores to stars: searching for a universal rule for star formation

Star formation is generally considered to be ‘universal’, meaning that it is statistically the same everywhere (and at all times). We investigate whether it is possible to find a simple rule for the conversion of molecular cores into bound stellar systems, along with the resulting secular decay and dynamical destruction of these systems, which can match the field initial mass functions (IMFs) and multiplicity statistics. We find that extreme cases, in which the core fragmentation is self-similar or has a strong dependence on initial core mass, cannot reproduce the observations of the field. However, a model in which core fragmentation is fairly weakly dependent on core mass has some success, if we include the effects of secular decay on the multiplicity statistics. This model both fits the IMF well and has an overabundance of low-mass binary systems over the field that matches local star-forming regions. However, it is unclear whether this overabundance could be dynamically processed to match the field.