Double neutron star formation via consecutive type II supernova explosions

Since the discovery of first double neutron star (DNS) system, number these exotic binaries has reached fifteen. Here we investigate a channel DNS formation in binary systems with components above mass limit type II supernova explosion (SN II), i.e. 8 MSun. We apply spherically symmetric homologous envelope expansion model to account for loss, and follow dynamical evolution system numerically high-precision integrator. The SN occurs whose orbital parameters are pre-defined, then, is applied again newly formed system. Analysing 1 658 880 models find that via subsequent explosions requires fine-tuning initial parameters. Our can explain separation greater than 2.95 au. eccentricity spans wide range thanks circularisation effect due second explosion. sensitive progenitor position preceding In agreement majority observations systems, centre-of velocities be less 60 km/s. Neutron stars become unbound either gain peculiar velocity 0.02 - 240 our model, tight post-explosion orbit-shrinking mechanism, possibly driven by ejected envelopes.