2011MNRAS.414.1427V

The distribution of masses for neutron stars is analysed using the Bayesian statistical inference, evaluating the likelihood of the proposed Gaussian peaks by using 54 measured points obtained in a variety of systems. The results strongly suggest the existence of a bimodal distribution of the masses, with the first peak around 1.37 M_☉ and a much wider second peak at 1.73 M_☉. The results support earlier views related to the different evolutionary histories of the members for the first two peaks, which produces a natural separation (even if no attempt to `label' the systems has been made here). They also accommodate the recent findings of ∼M_☉masses quite naturally. Finally, we explore the existence of a subgroup around 1.25 M_☉, finding weak, if any, evidence for it. This recently claimed low-mass subgroup, possibly related to the O–Mg–Ne core collapse events, has a monotonically decreasing likelihood and does not stand out clearly from the rest of the sample.